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Data Structures | Typedefs | Functions

nodeWindowAgg.c File Reference

#include "postgres.h"
#include "access/htup_details.h"
#include "catalog/objectaccess.h"
#include "catalog/pg_aggregate.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "executor/executor.h"
#include "executor/nodeWindowAgg.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/clauses.h"
#include "parser/parse_agg.h"
#include "parser/parse_coerce.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/datum.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/syscache.h"
#include "windowapi.h"
Include dependency graph for nodeWindowAgg.c:

Go to the source code of this file.

Data Structures

struct  WindowObjectData
struct  WindowStatePerFuncData
struct  WindowStatePerAggData

Typedefs

typedef struct WindowObjectData WindowObjectData
typedef struct
WindowStatePerFuncData 
WindowStatePerFuncData
typedef struct
WindowStatePerAggData 
WindowStatePerAggData

Functions

static void initialize_windowaggregate (WindowAggState *winstate, WindowStatePerFunc perfuncstate, WindowStatePerAgg peraggstate)
static void advance_windowaggregate (WindowAggState *winstate, WindowStatePerFunc perfuncstate, WindowStatePerAgg peraggstate)
static void finalize_windowaggregate (WindowAggState *winstate, WindowStatePerFunc perfuncstate, WindowStatePerAgg peraggstate, Datum *result, bool *isnull)
static void eval_windowaggregates (WindowAggState *winstate)
static void eval_windowfunction (WindowAggState *winstate, WindowStatePerFunc perfuncstate, Datum *result, bool *isnull)
static void begin_partition (WindowAggState *winstate)
static void spool_tuples (WindowAggState *winstate, int64 pos)
static void release_partition (WindowAggState *winstate)
static bool row_is_in_frame (WindowAggState *winstate, int64 pos, TupleTableSlot *slot)
static void update_frameheadpos (WindowObject winobj, TupleTableSlot *slot)
static void update_frametailpos (WindowObject winobj, TupleTableSlot *slot)
static WindowStatePerAggDatainitialize_peragg (WindowAggState *winstate, WindowFunc *wfunc, WindowStatePerAgg peraggstate)
static Datum GetAggInitVal (Datum textInitVal, Oid transtype)
static bool are_peers (WindowAggState *winstate, TupleTableSlot *slot1, TupleTableSlot *slot2)
static bool window_gettupleslot (WindowObject winobj, int64 pos, TupleTableSlot *slot)
TupleTableSlotExecWindowAgg (WindowAggState *winstate)
WindowAggStateExecInitWindowAgg (WindowAgg *node, EState *estate, int eflags)
void ExecEndWindowAgg (WindowAggState *node)
void ExecReScanWindowAgg (WindowAggState *node)
void * WinGetPartitionLocalMemory (WindowObject winobj, Size sz)
int64 WinGetCurrentPosition (WindowObject winobj)
int64 WinGetPartitionRowCount (WindowObject winobj)
void WinSetMarkPosition (WindowObject winobj, int64 markpos)
bool WinRowsArePeers (WindowObject winobj, int64 pos1, int64 pos2)
Datum WinGetFuncArgInPartition (WindowObject winobj, int argno, int relpos, int seektype, bool set_mark, bool *isnull, bool *isout)
Datum WinGetFuncArgInFrame (WindowObject winobj, int argno, int relpos, int seektype, bool set_mark, bool *isnull, bool *isout)
Datum WinGetFuncArgCurrent (WindowObject winobj, int argno, bool *isnull)

Typedef Documentation


Function Documentation

static void advance_windowaggregate ( WindowAggState winstate,
WindowStatePerFunc  perfuncstate,
WindowStatePerAgg  peraggstate 
) [static]

Definition at line 217 of file nodeWindowAgg.c.

References WindowAggState::aggcontext, FunctionCallInfoData::arg, arg, FunctionCallInfoData::argnull, WindowFuncExprState::args, datumCopy(), DatumGetPointer, ExprContext::ecxt_per_tuple_memory, ExecEvalExpr, FmgrInfo::fn_strict, FunctionCallInvoke, i, InitFunctionCallInfoData, FunctionCallInfoData::isnull, lfirst, MemoryContextSwitchTo(), WindowStatePerAggData::noTransValue, NULL, WindowStatePerFuncData::numArguments, pfree(), WindowAggState::tmpcontext, WindowStatePerAggData::transfn, WindowStatePerAggData::transtypeByVal, WindowStatePerAggData::transtypeLen, WindowStatePerAggData::transValue, WindowStatePerAggData::transValueIsNull, WindowStatePerFuncData::wfuncstate, and WindowStatePerFuncData::winCollation.

Referenced by eval_windowaggregates().

{
    WindowFuncExprState *wfuncstate = perfuncstate->wfuncstate;
    int         numArguments = perfuncstate->numArguments;
    FunctionCallInfoData fcinfodata;
    FunctionCallInfo fcinfo = &fcinfodata;
    Datum       newVal;
    ListCell   *arg;
    int         i;
    MemoryContext oldContext;
    ExprContext *econtext = winstate->tmpcontext;

    oldContext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);

    /* We start from 1, since the 0th arg will be the transition value */
    i = 1;
    foreach(arg, wfuncstate->args)
    {
        ExprState  *argstate = (ExprState *) lfirst(arg);

        fcinfo->arg[i] = ExecEvalExpr(argstate, econtext,
                                      &fcinfo->argnull[i], NULL);
        i++;
    }

    if (peraggstate->transfn.fn_strict)
    {
        /*
         * For a strict transfn, nothing happens when there's a NULL input; we
         * just keep the prior transValue.
         */
        for (i = 1; i <= numArguments; i++)
        {
            if (fcinfo->argnull[i])
            {
                MemoryContextSwitchTo(oldContext);
                return;
            }
        }
        if (peraggstate->noTransValue)
        {
            /*
             * transValue has not been initialized. This is the first non-NULL
             * input value. We use it as the initial value for transValue. (We
             * already checked that the agg's input type is binary-compatible
             * with its transtype, so straight copy here is OK.)
             *
             * We must copy the datum into aggcontext if it is pass-by-ref. We
             * do not need to pfree the old transValue, since it's NULL.
             */
            MemoryContextSwitchTo(winstate->aggcontext);
            peraggstate->transValue = datumCopy(fcinfo->arg[1],
                                                peraggstate->transtypeByVal,
                                                peraggstate->transtypeLen);
            peraggstate->transValueIsNull = false;
            peraggstate->noTransValue = false;
            MemoryContextSwitchTo(oldContext);
            return;
        }
        if (peraggstate->transValueIsNull)
        {
            /*
             * Don't call a strict function with NULL inputs.  Note it is
             * possible to get here despite the above tests, if the transfn is
             * strict *and* returned a NULL on a prior cycle. If that happens
             * we will propagate the NULL all the way to the end.
             */
            MemoryContextSwitchTo(oldContext);
            return;
        }
    }

    /*
     * OK to call the transition function
     */
    InitFunctionCallInfoData(*fcinfo, &(peraggstate->transfn),
                             numArguments + 1,
                             perfuncstate->winCollation,
                             (void *) winstate, NULL);
    fcinfo->arg[0] = peraggstate->transValue;
    fcinfo->argnull[0] = peraggstate->transValueIsNull;
    newVal = FunctionCallInvoke(fcinfo);

    /*
     * If pass-by-ref datatype, must copy the new value into aggcontext and
     * pfree the prior transValue.  But if transfn returned a pointer to its
     * first input, we don't need to do anything.
     */
    if (!peraggstate->transtypeByVal &&
        DatumGetPointer(newVal) != DatumGetPointer(peraggstate->transValue))
    {
        if (!fcinfo->isnull)
        {
            MemoryContextSwitchTo(winstate->aggcontext);
            newVal = datumCopy(newVal,
                               peraggstate->transtypeByVal,
                               peraggstate->transtypeLen);
        }
        if (!peraggstate->transValueIsNull)
            pfree(DatumGetPointer(peraggstate->transValue));
    }

    MemoryContextSwitchTo(oldContext);
    peraggstate->transValue = newVal;
    peraggstate->transValueIsNull = fcinfo->isnull;
}

static bool are_peers ( WindowAggState winstate,
TupleTableSlot slot1,
TupleTableSlot slot2 
) [static]

Definition at line 1888 of file nodeWindowAgg.c.

References ExprContext::ecxt_per_tuple_memory, execTuplesMatch(), WindowAgg::ordColIdx, WindowAggState::ordEqfunctions, WindowAgg::ordNumCols, PlanState::plan, ScanState::ps, WindowAggState::ss, and WindowAggState::tmpcontext.

Referenced by row_is_in_frame(), update_frameheadpos(), update_frametailpos(), and WinRowsArePeers().

{
    WindowAgg  *node = (WindowAgg *) winstate->ss.ps.plan;

    /* If no ORDER BY, all rows are peers with each other */
    if (node->ordNumCols == 0)
        return true;

    return execTuplesMatch(slot1, slot2,
                           node->ordNumCols, node->ordColIdx,
                           winstate->ordEqfunctions,
                           winstate->tmpcontext->ecxt_per_tuple_memory);
}

static void begin_partition ( WindowAggState winstate  )  [static]

Definition at line 664 of file nodeWindowAgg.c.

References WindowAggState::agg_row_slot, WindowAggState::agg_winobj, WindowAggState::aggregatedbase, WindowAggState::aggregatedupto, WindowAggState::buffer, WindowAggState::current_ptr, WindowAggState::currentpos, EXEC_FLAG_BACKWARD, ExecClearTuple(), ExecCopySlot(), ExecProcNode(), WindowAggState::first_part_slot, WindowAggState::framehead_valid, WindowAggState::frameheadpos, FRAMEOPTION_START_UNBOUNDED_PRECEDING, WindowAggState::frameOptions, WindowAggState::frametail_valid, WindowAggState::frametailpos, i, WindowObjectData::markpos, WindowObjectData::markptr, WindowAggState::more_partitions, WindowAggState::numaggs, WindowAggState::numfuncs, outerPlan, outerPlanState, WindowAggState::partition_spooled, WindowAggState::perfunc, WindowStatePerFuncData::plain_agg, WindowObjectData::readptr, WindowObjectData::seekpos, WindowAggState::spooled_rows, TupIsNull, tuplestore_alloc_read_pointer(), tuplestore_begin_heap(), tuplestore_puttupleslot(), tuplestore_set_eflags(), WindowStatePerFuncData::winobj, and work_mem.

Referenced by ExecWindowAgg().

{
    PlanState  *outerPlan = outerPlanState(winstate);
    int         numfuncs = winstate->numfuncs;
    int         i;

    winstate->partition_spooled = false;
    winstate->framehead_valid = false;
    winstate->frametail_valid = false;
    winstate->spooled_rows = 0;
    winstate->currentpos = 0;
    winstate->frameheadpos = 0;
    winstate->frametailpos = -1;
    ExecClearTuple(winstate->agg_row_slot);

    /*
     * If this is the very first partition, we need to fetch the first input
     * row to store in first_part_slot.
     */
    if (TupIsNull(winstate->first_part_slot))
    {
        TupleTableSlot *outerslot = ExecProcNode(outerPlan);

        if (!TupIsNull(outerslot))
            ExecCopySlot(winstate->first_part_slot, outerslot);
        else
        {
            /* outer plan is empty, so we have nothing to do */
            winstate->partition_spooled = true;
            winstate->more_partitions = false;
            return;
        }
    }

    /* Create new tuplestore for this partition */
    winstate->buffer = tuplestore_begin_heap(false, false, work_mem);

    /*
     * Set up read pointers for the tuplestore.  The current pointer doesn't
     * need BACKWARD capability, but the per-window-function read pointers do,
     * and the aggregate pointer does if frame start is movable.
     */
    winstate->current_ptr = 0;  /* read pointer 0 is pre-allocated */

    /* reset default REWIND capability bit for current ptr */
    tuplestore_set_eflags(winstate->buffer, 0);

    /* create read pointers for aggregates, if needed */
    if (winstate->numaggs > 0)
    {
        WindowObject agg_winobj = winstate->agg_winobj;
        int         readptr_flags = 0;

        /* If the frame head is potentially movable ... */
        if (!(winstate->frameOptions & FRAMEOPTION_START_UNBOUNDED_PRECEDING))
        {
            /* ... create a mark pointer to track the frame head */
            agg_winobj->markptr = tuplestore_alloc_read_pointer(winstate->buffer, 0);
            /* and the read pointer will need BACKWARD capability */
            readptr_flags |= EXEC_FLAG_BACKWARD;
        }

        agg_winobj->readptr = tuplestore_alloc_read_pointer(winstate->buffer,
                                                            readptr_flags);
        agg_winobj->markpos = -1;
        agg_winobj->seekpos = -1;

        /* Also reset the row counters for aggregates */
        winstate->aggregatedbase = 0;
        winstate->aggregatedupto = 0;
    }

    /* create mark and read pointers for each real window function */
    for (i = 0; i < numfuncs; i++)
    {
        WindowStatePerFunc perfuncstate = &(winstate->perfunc[i]);

        if (!perfuncstate->plain_agg)
        {
            WindowObject winobj = perfuncstate->winobj;

            winobj->markptr = tuplestore_alloc_read_pointer(winstate->buffer,
                                                            0);
            winobj->readptr = tuplestore_alloc_read_pointer(winstate->buffer,
                                                         EXEC_FLAG_BACKWARD);
            winobj->markpos = -1;
            winobj->seekpos = -1;
        }
    }

    /*
     * Store the first tuple into the tuplestore (it's always available now;
     * we either read it above, or saved it at the end of previous partition)
     */
    tuplestore_puttupleslot(winstate->buffer, winstate->first_part_slot);
    winstate->spooled_rows++;
}

static void eval_windowaggregates ( WindowAggState winstate  )  [static]

Definition at line 392 of file nodeWindowAgg.c.

References advance_windowaggregate(), WindowAggState::agg_row_slot, WindowAggState::agg_winobj, WindowAggState::aggcontext, WindowAggState::aggregatedbase, WindowAggState::aggregatedupto, WindowAggState::currentpos, datumCopy(), DatumGetPointer, ExprContext::ecxt_aggnulls, ExprContext::ecxt_aggvalues, ExprContext::ecxt_outertuple, ExecClearTuple(), finalize_windowaggregate(), WindowAggState::frameheadpos, FRAMEOPTION_END_CURRENT_ROW, FRAMEOPTION_END_UNBOUNDED_FOLLOWING, WindowAggState::frameOptions, i, initialize_windowaggregate(), WindowObjectData::markptr, MemoryContextResetAndDeleteChildren(), MemoryContextSwitchTo(), WindowAggState::numaggs, WindowAggState::peragg, WindowAggState::perfunc, pfree(), ScanState::ps, PlanState::ps_ExprContext, ResetExprContext, WindowStatePerAggData::resulttypeByVal, WindowStatePerAggData::resulttypeLen, WindowStatePerAggData::resultValue, WindowStatePerAggData::resultValueIsNull, row_is_in_frame(), WindowAggState::ss, WindowAggState::temp_slot_1, WindowAggState::tmpcontext, TupIsNull, update_frameheadpos(), WindowStatePerAggData::wfuncno, window_gettupleslot(), and WinSetMarkPosition().

Referenced by ExecWindowAgg().

{
    WindowStatePerAgg peraggstate;
    int         wfuncno,
                numaggs;
    int         i;
    MemoryContext oldContext;
    ExprContext *econtext;
    WindowObject agg_winobj;
    TupleTableSlot *agg_row_slot;

    numaggs = winstate->numaggs;
    if (numaggs == 0)
        return;                 /* nothing to do */

    /* final output execution is in ps_ExprContext */
    econtext = winstate->ss.ps.ps_ExprContext;
    agg_winobj = winstate->agg_winobj;
    agg_row_slot = winstate->agg_row_slot;

    /*
     * Currently, we support only a subset of the SQL-standard window framing
     * rules.
     *
     * If the frame start is UNBOUNDED_PRECEDING, the window frame consists of
     * a contiguous group of rows extending forward from the start of the
     * partition, and rows only enter the frame, never exit it, as the current
     * row advances forward.  This makes it possible to use an incremental
     * strategy for evaluating aggregates: we run the transition function for
     * each row added to the frame, and run the final function whenever we
     * need the current aggregate value.  This is considerably more efficient
     * than the naive approach of re-running the entire aggregate calculation
     * for each current row.  It does assume that the final function doesn't
     * damage the running transition value, but we have the same assumption in
     * nodeAgg.c too (when it rescans an existing hash table).
     *
     * For other frame start rules, we discard the aggregate state and re-run
     * the aggregates whenever the frame head row moves.  We can still
     * optimize as above whenever successive rows share the same frame head.
     *
     * In many common cases, multiple rows share the same frame and hence the
     * same aggregate value. (In particular, if there's no ORDER BY in a RANGE
     * window, then all rows are peers and so they all have window frame equal
     * to the whole partition.)  We optimize such cases by calculating the
     * aggregate value once when we reach the first row of a peer group, and
     * then returning the saved value for all subsequent rows.
     *
     * 'aggregatedupto' keeps track of the first row that has not yet been
     * accumulated into the aggregate transition values.  Whenever we start a
     * new peer group, we accumulate forward to the end of the peer group.
     *
     * TODO: Rerunning aggregates from the frame start can be pretty slow. For
     * some aggregates like SUM and COUNT we could avoid that by implementing
     * a "negative transition function" that would be called for each row as
     * it exits the frame.  We'd have to think about avoiding recalculation of
     * volatile arguments of aggregate functions, too.
     */

    /*
     * First, update the frame head position.
     */
    update_frameheadpos(agg_winobj, winstate->temp_slot_1);

    /*
     * Initialize aggregates on first call for partition, or if the frame head
     * position moved since last time.
     */
    if (winstate->currentpos == 0 ||
        winstate->frameheadpos != winstate->aggregatedbase)
    {
        /*
         * Discard transient aggregate values
         */
        MemoryContextResetAndDeleteChildren(winstate->aggcontext);

        for (i = 0; i < numaggs; i++)
        {
            peraggstate = &winstate->peragg[i];
            wfuncno = peraggstate->wfuncno;
            initialize_windowaggregate(winstate,
                                       &winstate->perfunc[wfuncno],
                                       peraggstate);
        }

        /*
         * If we created a mark pointer for aggregates, keep it pushed up to
         * frame head, so that tuplestore can discard unnecessary rows.
         */
        if (agg_winobj->markptr >= 0)
            WinSetMarkPosition(agg_winobj, winstate->frameheadpos);

        /*
         * Initialize for loop below
         */
        ExecClearTuple(agg_row_slot);
        winstate->aggregatedbase = winstate->frameheadpos;
        winstate->aggregatedupto = winstate->frameheadpos;
    }

    /*
     * In UNBOUNDED_FOLLOWING mode, we don't have to recalculate aggregates
     * except when the frame head moves.  In END_CURRENT_ROW mode, we only
     * have to recalculate when the frame head moves or currentpos has
     * advanced past the place we'd aggregated up to.  Check for these cases
     * and if so, reuse the saved result values.
     */
    if ((winstate->frameOptions & (FRAMEOPTION_END_UNBOUNDED_FOLLOWING |
                                   FRAMEOPTION_END_CURRENT_ROW)) &&
        winstate->aggregatedbase <= winstate->currentpos &&
        winstate->aggregatedupto > winstate->currentpos)
    {
        for (i = 0; i < numaggs; i++)
        {
            peraggstate = &winstate->peragg[i];
            wfuncno = peraggstate->wfuncno;
            econtext->ecxt_aggvalues[wfuncno] = peraggstate->resultValue;
            econtext->ecxt_aggnulls[wfuncno] = peraggstate->resultValueIsNull;
        }
        return;
    }

    /*
     * Advance until we reach a row not in frame (or end of partition).
     *
     * Note the loop invariant: agg_row_slot is either empty or holds the row
     * at position aggregatedupto.  We advance aggregatedupto after processing
     * a row.
     */
    for (;;)
    {
        /* Fetch next row if we didn't already */
        if (TupIsNull(agg_row_slot))
        {
            if (!window_gettupleslot(agg_winobj, winstate->aggregatedupto,
                                     agg_row_slot))
                break;          /* must be end of partition */
        }

        /* Exit loop (for now) if not in frame */
        if (!row_is_in_frame(winstate, winstate->aggregatedupto, agg_row_slot))
            break;

        /* Set tuple context for evaluation of aggregate arguments */
        winstate->tmpcontext->ecxt_outertuple = agg_row_slot;

        /* Accumulate row into the aggregates */
        for (i = 0; i < numaggs; i++)
        {
            peraggstate = &winstate->peragg[i];
            wfuncno = peraggstate->wfuncno;
            advance_windowaggregate(winstate,
                                    &winstate->perfunc[wfuncno],
                                    peraggstate);
        }

        /* Reset per-input-tuple context after each tuple */
        ResetExprContext(winstate->tmpcontext);

        /* And advance the aggregated-row state */
        winstate->aggregatedupto++;
        ExecClearTuple(agg_row_slot);
    }

    /*
     * finalize aggregates and fill result/isnull fields.
     */
    for (i = 0; i < numaggs; i++)
    {
        Datum      *result;
        bool       *isnull;

        peraggstate = &winstate->peragg[i];
        wfuncno = peraggstate->wfuncno;
        result = &econtext->ecxt_aggvalues[wfuncno];
        isnull = &econtext->ecxt_aggnulls[wfuncno];
        finalize_windowaggregate(winstate,
                                 &winstate->perfunc[wfuncno],
                                 peraggstate,
                                 result, isnull);

        /*
         * save the result in case next row shares the same frame.
         *
         * XXX in some framing modes, eg ROWS/END_CURRENT_ROW, we can know in
         * advance that the next row can't possibly share the same frame. Is
         * it worth detecting that and skipping this code?
         */
        if (!peraggstate->resulttypeByVal)
        {
            /*
             * clear old resultValue in order not to leak memory.  (Note: the
             * new result can't possibly be the same datum as old resultValue,
             * because we never passed it to the trans function.)
             */
            if (!peraggstate->resultValueIsNull)
                pfree(DatumGetPointer(peraggstate->resultValue));

            /*
             * If pass-by-ref, copy it into our aggregate context.
             */
            if (!*isnull)
            {
                oldContext = MemoryContextSwitchTo(winstate->aggcontext);
                peraggstate->resultValue =
                    datumCopy(*result,
                              peraggstate->resulttypeByVal,
                              peraggstate->resulttypeLen);
                MemoryContextSwitchTo(oldContext);
            }
        }
        else
        {
            peraggstate->resultValue = *result;
        }
        peraggstate->resultValueIsNull = *isnull;
    }
}

static void eval_windowfunction ( WindowAggState winstate,
WindowStatePerFunc  perfuncstate,
Datum result,
bool isnull 
) [static]

Definition at line 620 of file nodeWindowAgg.c.

References FunctionCallInfoData::argnull, CurrentMemoryContext, datumCopy(), DatumGetPointer, ExprContext::ecxt_per_tuple_memory, WindowStatePerFuncData::flinfo, FunctionCallInvoke, InitFunctionCallInfoData, FunctionCallInfoData::isnull, MemoryContextContains(), MemoryContextSwitchTo(), NULL, WindowStatePerFuncData::numArguments, ScanState::ps, PlanState::ps_ExprContext, WindowStatePerFuncData::resulttypeByVal, WindowStatePerFuncData::resulttypeLen, WindowAggState::ss, WindowStatePerFuncData::winCollation, and WindowStatePerFuncData::winobj.

Referenced by ExecWindowAgg().

{
    FunctionCallInfoData fcinfo;
    MemoryContext oldContext;

    oldContext = MemoryContextSwitchTo(winstate->ss.ps.ps_ExprContext->ecxt_per_tuple_memory);

    /*
     * We don't pass any normal arguments to a window function, but we do pass
     * it the number of arguments, in order to permit window function
     * implementations to support varying numbers of arguments.  The real info
     * goes through the WindowObject, which is passed via fcinfo->context.
     */
    InitFunctionCallInfoData(fcinfo, &(perfuncstate->flinfo),
                             perfuncstate->numArguments,
                             perfuncstate->winCollation,
                             (void *) perfuncstate->winobj, NULL);
    /* Just in case, make all the regular argument slots be null */
    memset(fcinfo.argnull, true, perfuncstate->numArguments);

    *result = FunctionCallInvoke(&fcinfo);
    *isnull = fcinfo.isnull;

    /*
     * Make sure pass-by-ref data is allocated in the appropriate context. (We
     * need this in case the function returns a pointer into some short-lived
     * tuple, as is entirely possible.)
     */
    if (!perfuncstate->resulttypeByVal && !fcinfo.isnull &&
        !MemoryContextContains(CurrentMemoryContext,
                               DatumGetPointer(*result)))
        *result = datumCopy(*result,
                            perfuncstate->resulttypeByVal,
                            perfuncstate->resulttypeLen);

    MemoryContextSwitchTo(oldContext);
}

void ExecEndWindowAgg ( WindowAggState node  ) 
WindowAggState* ExecInitWindowAgg ( WindowAgg node,
EState estate,
int  eflags 
)

Definition at line 1398 of file nodeWindowAgg.c.

References ACL_EXECUTE, ACL_KIND_PROC, aclcheck_error(), ACLCHECK_OK, WindowAggState::agg_row_slot, WindowAggState::agg_winobj, WindowAggState::aggcontext, ALLOCSET_DEFAULT_INITSIZE, ALLOCSET_DEFAULT_MAXSIZE, ALLOCSET_DEFAULT_MINSIZE, AllocSetContextCreate(), WindowFuncExprState::args, WindowObjectData::argstates, Assert, contain_volatile_functions(), CurrentMemoryContext, ExprContext::ecxt_aggnulls, ExprContext::ecxt_aggvalues, ExprContext::ecxt_per_query_memory, elog, WindowAgg::endOffset, equal(), ERROR, EXEC_FLAG_BACKWARD, EXEC_FLAG_MARK, ExecAssignExprContext(), ExecAssignProjectionInfo(), ExecAssignResultTypeFromTL(), ExecAssignScanTypeFromOuterPlan(), ExecInitExpr(), ExecInitExtraTupleSlot(), ExecInitNode(), ExecInitResultTupleSlot(), ExecInitScanTupleSlot(), ExecSetSlotDescriptor(), execTuplesMatchPrepare(), ExprState::expr, WindowAggState::first_part_slot, fmgr_info_cxt(), fmgr_info_set_expr, WindowAgg::frameOptions, WindowAggState::frameOptions, WindowAggState::funcs, get_func_name(), get_typlenbyval(), GetUserId(), i, initialize_peragg(), InvokeFunctionExecuteHook, lfirst, list_length(), WindowObjectData::localmem, makeNode, WindowObjectData::markptr, NIL, NULL, WindowAggState::numaggs, WindowAggState::numfuncs, WindowAggState::ordEqfunctions, WindowAgg::ordNumCols, WindowAgg::ordOperators, outerPlan, outerPlanState, palloc0(), WindowAggState::partcontext, WindowAggState::partEqfunctions, WindowAgg::partNumCols, WindowAgg::partOperators, WindowAggState::peragg, WindowAggState::perfunc, pg_proc_aclcheck(), WindowAgg::plan, PlanState::plan, ScanState::ps, PlanState::ps_ExprContext, PlanState::ps_TupFromTlist, PlanState::qual, Plan::qual, WindowObjectData::readptr, WindowAggState::ss, ScanState::ss_ScanTupleSlot, WindowAgg::startOffset, WindowAggState::startOffset, PlanState::state, Plan::targetlist, PlanState::targetlist, WindowAggState::temp_slot_1, WindowAggState::temp_slot_2, WindowAggState::tmpcontext, TupleTableSlot::tts_tupleDescriptor, WindowStatePerAggData::wfuncno, WindowFuncExprState::wfuncno, WindowFunc::winfnoid, WindowAgg::winref, WindowFunc::winref, WindowObjectData::winstate, and WindowFuncExprState::xprstate.

Referenced by ExecInitNode().

{
    WindowAggState *winstate;
    Plan       *outerPlan;
    ExprContext *econtext;
    ExprContext *tmpcontext;
    WindowStatePerFunc perfunc;
    WindowStatePerAgg peragg;
    int         numfuncs,
                wfuncno,
                numaggs,
                aggno;
    ListCell   *l;

    /* check for unsupported flags */
    Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));

    /*
     * create state structure
     */
    winstate = makeNode(WindowAggState);
    winstate->ss.ps.plan = (Plan *) node;
    winstate->ss.ps.state = estate;

    /*
     * Create expression contexts.  We need two, one for per-input-tuple
     * processing and one for per-output-tuple processing.  We cheat a little
     * by using ExecAssignExprContext() to build both.
     */
    ExecAssignExprContext(estate, &winstate->ss.ps);
    tmpcontext = winstate->ss.ps.ps_ExprContext;
    winstate->tmpcontext = tmpcontext;
    ExecAssignExprContext(estate, &winstate->ss.ps);

    /* Create long-lived context for storage of partition-local memory etc */
    winstate->partcontext =
        AllocSetContextCreate(CurrentMemoryContext,
                              "WindowAgg_Partition",
                              ALLOCSET_DEFAULT_MINSIZE,
                              ALLOCSET_DEFAULT_INITSIZE,
                              ALLOCSET_DEFAULT_MAXSIZE);

    /* Create mid-lived context for aggregate trans values etc */
    winstate->aggcontext =
        AllocSetContextCreate(CurrentMemoryContext,
                              "WindowAgg_Aggregates",
                              ALLOCSET_DEFAULT_MINSIZE,
                              ALLOCSET_DEFAULT_INITSIZE,
                              ALLOCSET_DEFAULT_MAXSIZE);

    /*
     * tuple table initialization
     */
    ExecInitScanTupleSlot(estate, &winstate->ss);
    ExecInitResultTupleSlot(estate, &winstate->ss.ps);
    winstate->first_part_slot = ExecInitExtraTupleSlot(estate);
    winstate->agg_row_slot = ExecInitExtraTupleSlot(estate);
    winstate->temp_slot_1 = ExecInitExtraTupleSlot(estate);
    winstate->temp_slot_2 = ExecInitExtraTupleSlot(estate);

    winstate->ss.ps.targetlist = (List *)
        ExecInitExpr((Expr *) node->plan.targetlist,
                     (PlanState *) winstate);

    /*
     * WindowAgg nodes never have quals, since they can only occur at the
     * logical top level of a query (ie, after any WHERE or HAVING filters)
     */
    Assert(node->plan.qual == NIL);
    winstate->ss.ps.qual = NIL;

    /*
     * initialize child nodes
     */
    outerPlan = outerPlan(node);
    outerPlanState(winstate) = ExecInitNode(outerPlan, estate, eflags);

    /*
     * initialize source tuple type (which is also the tuple type that we'll
     * store in the tuplestore and use in all our working slots).
     */
    ExecAssignScanTypeFromOuterPlan(&winstate->ss);

    ExecSetSlotDescriptor(winstate->first_part_slot,
                          winstate->ss.ss_ScanTupleSlot->tts_tupleDescriptor);
    ExecSetSlotDescriptor(winstate->agg_row_slot,
                          winstate->ss.ss_ScanTupleSlot->tts_tupleDescriptor);
    ExecSetSlotDescriptor(winstate->temp_slot_1,
                          winstate->ss.ss_ScanTupleSlot->tts_tupleDescriptor);
    ExecSetSlotDescriptor(winstate->temp_slot_2,
                          winstate->ss.ss_ScanTupleSlot->tts_tupleDescriptor);

    /*
     * Initialize result tuple type and projection info.
     */
    ExecAssignResultTypeFromTL(&winstate->ss.ps);
    ExecAssignProjectionInfo(&winstate->ss.ps, NULL);

    winstate->ss.ps.ps_TupFromTlist = false;

    /* Set up data for comparing tuples */
    if (node->partNumCols > 0)
        winstate->partEqfunctions = execTuplesMatchPrepare(node->partNumCols,
                                                        node->partOperators);
    if (node->ordNumCols > 0)
        winstate->ordEqfunctions = execTuplesMatchPrepare(node->ordNumCols,
                                                          node->ordOperators);

    /*
     * WindowAgg nodes use aggvalues and aggnulls as well as Agg nodes.
     */
    numfuncs = winstate->numfuncs;
    numaggs = winstate->numaggs;
    econtext = winstate->ss.ps.ps_ExprContext;
    econtext->ecxt_aggvalues = (Datum *) palloc0(sizeof(Datum) * numfuncs);
    econtext->ecxt_aggnulls = (bool *) palloc0(sizeof(bool) * numfuncs);

    /*
     * allocate per-wfunc/per-agg state information.
     */
    perfunc = (WindowStatePerFunc) palloc0(sizeof(WindowStatePerFuncData) * numfuncs);
    peragg = (WindowStatePerAgg) palloc0(sizeof(WindowStatePerAggData) * numaggs);
    winstate->perfunc = perfunc;
    winstate->peragg = peragg;

    wfuncno = -1;
    aggno = -1;
    foreach(l, winstate->funcs)
    {
        WindowFuncExprState *wfuncstate = (WindowFuncExprState *) lfirst(l);
        WindowFunc *wfunc = (WindowFunc *) wfuncstate->xprstate.expr;
        WindowStatePerFunc perfuncstate;
        AclResult   aclresult;
        int         i;

        if (wfunc->winref != node->winref)      /* planner screwed up? */
            elog(ERROR, "WindowFunc with winref %u assigned to WindowAgg with winref %u",
                 wfunc->winref, node->winref);

        /* Look for a previous duplicate window function */
        for (i = 0; i <= wfuncno; i++)
        {
            if (equal(wfunc, perfunc[i].wfunc) &&
                !contain_volatile_functions((Node *) wfunc))
                break;
        }
        if (i <= wfuncno)
        {
            /* Found a match to an existing entry, so just mark it */
            wfuncstate->wfuncno = i;
            continue;
        }

        /* Nope, so assign a new PerAgg record */
        perfuncstate = &perfunc[++wfuncno];

        /* Mark WindowFunc state node with assigned index in the result array */
        wfuncstate->wfuncno = wfuncno;

        /* Check permission to call window function */
        aclresult = pg_proc_aclcheck(wfunc->winfnoid, GetUserId(),
                                     ACL_EXECUTE);
        if (aclresult != ACLCHECK_OK)
            aclcheck_error(aclresult, ACL_KIND_PROC,
                           get_func_name(wfunc->winfnoid));
        InvokeFunctionExecuteHook(wfunc->winfnoid);

        /* Fill in the perfuncstate data */
        perfuncstate->wfuncstate = wfuncstate;
        perfuncstate->wfunc = wfunc;
        perfuncstate->numArguments = list_length(wfuncstate->args);

        fmgr_info_cxt(wfunc->winfnoid, &perfuncstate->flinfo,
                      econtext->ecxt_per_query_memory);
        fmgr_info_set_expr((Node *) wfunc, &perfuncstate->flinfo);

        perfuncstate->winCollation = wfunc->inputcollid;

        get_typlenbyval(wfunc->wintype,
                        &perfuncstate->resulttypeLen,
                        &perfuncstate->resulttypeByVal);

        /*
         * If it's really just a plain aggregate function, we'll emulate the
         * Agg environment for it.
         */
        perfuncstate->plain_agg = wfunc->winagg;
        if (wfunc->winagg)
        {
            WindowStatePerAgg peraggstate;

            perfuncstate->aggno = ++aggno;
            peraggstate = &winstate->peragg[aggno];
            initialize_peragg(winstate, wfunc, peraggstate);
            peraggstate->wfuncno = wfuncno;
        }
        else
        {
            WindowObject winobj = makeNode(WindowObjectData);

            winobj->winstate = winstate;
            winobj->argstates = wfuncstate->args;
            winobj->localmem = NULL;
            perfuncstate->winobj = winobj;
        }
    }

    /* Update numfuncs, numaggs to match number of unique functions found */
    winstate->numfuncs = wfuncno + 1;
    winstate->numaggs = aggno + 1;

    /* Set up WindowObject for aggregates, if needed */
    if (winstate->numaggs > 0)
    {
        WindowObject agg_winobj = makeNode(WindowObjectData);

        agg_winobj->winstate = winstate;
        agg_winobj->argstates = NIL;
        agg_winobj->localmem = NULL;
        /* make sure markptr = -1 to invalidate. It may not get used */
        agg_winobj->markptr = -1;
        agg_winobj->readptr = -1;
        winstate->agg_winobj = agg_winobj;
    }

    /* copy frame options to state node for easy access */
    winstate->frameOptions = node->frameOptions;

    /* initialize frame bound offset expressions */
    winstate->startOffset = ExecInitExpr((Expr *) node->startOffset,
                                         (PlanState *) winstate);
    winstate->endOffset = ExecInitExpr((Expr *) node->endOffset,
                                       (PlanState *) winstate);

    winstate->all_first = true;
    winstate->partition_spooled = false;
    winstate->more_partitions = false;

    return winstate;
}

void ExecReScanWindowAgg ( WindowAggState node  ) 

Definition at line 1678 of file nodeWindowAgg.c.

References WindowAggState::agg_row_slot, WindowAggState::all_done, WindowAggState::all_first, PlanState::chgParam, ExprContext::ecxt_aggnulls, ExprContext::ecxt_aggvalues, ExecClearTuple(), ExecReScan(), WindowAggState::first_part_slot, PlanState::lefttree, MemSet, NULL, WindowAggState::numfuncs, ScanState::ps, PlanState::ps_ExprContext, PlanState::ps_TupFromTlist, release_partition(), WindowAggState::ss, ScanState::ss_ScanTupleSlot, WindowAggState::temp_slot_1, and WindowAggState::temp_slot_2.

Referenced by ExecReScan().

{
    ExprContext *econtext = node->ss.ps.ps_ExprContext;

    node->all_done = false;

    node->ss.ps.ps_TupFromTlist = false;
    node->all_first = true;

    /* release tuplestore et al */
    release_partition(node);

    /* release all temp tuples, but especially first_part_slot */
    ExecClearTuple(node->ss.ss_ScanTupleSlot);
    ExecClearTuple(node->first_part_slot);
    ExecClearTuple(node->agg_row_slot);
    ExecClearTuple(node->temp_slot_1);
    ExecClearTuple(node->temp_slot_2);

    /* Forget current wfunc values */
    MemSet(econtext->ecxt_aggvalues, 0, sizeof(Datum) * node->numfuncs);
    MemSet(econtext->ecxt_aggnulls, 0, sizeof(bool) * node->numfuncs);

    /*
     * if chgParam of subnode is not null then plan will be re-scanned by
     * first ExecProcNode.
     */
    if (node->ss.ps.lefttree->chgParam == NULL)
        ExecReScan(node->ss.ps.lefttree);
}

TupleTableSlot* ExecWindowAgg ( WindowAggState winstate  ) 

Definition at line 1190 of file nodeWindowAgg.c.

References WindowAggState::all_done, WindowAggState::all_first, Assert, begin_partition(), WindowAggState::buffer, WindowAggState::current_ptr, WindowAggState::currentpos, datumCopy(), DatumGetInt64, ExprContext::ecxt_aggnulls, ExprContext::ecxt_aggvalues, ExprContext::ecxt_outertuple, elog, WindowAggState::endOffset, WindowAggState::endOffsetValue, ereport, errcode(), errmsg(), ERROR, eval_windowaggregates(), eval_windowfunction(), ExecEvalExprSwitchContext(), ExecProject(), ExprState::expr, ExprEndResult, ExprMultipleResult, exprType(), WindowAggState::framehead_valid, FRAMEOPTION_END_VALUE, FRAMEOPTION_ROWS, FRAMEOPTION_START_VALUE, WindowAggState::frameOptions, WindowAggState::frametail_valid, get_typlenbyval(), i, WindowAggState::more_partitions, NULL, WindowAggState::numaggs, WindowAggState::numfuncs, WindowAggState::partition_spooled, WindowAggState::perfunc, WindowStatePerFuncData::plain_agg, ScanState::ps, PlanState::ps_ExprContext, PlanState::ps_ProjInfo, PlanState::ps_TupFromTlist, release_partition(), ResetExprContext, spool_tuples(), WindowAggState::spooled_rows, WindowAggState::ss, ScanState::ss_ScanTupleSlot, WindowAggState::startOffset, WindowAggState::startOffsetValue, tuplestore_gettupleslot(), tuplestore_select_read_pointer(), tuplestore_trim(), value, WindowFuncExprState::wfuncno, and WindowStatePerFuncData::wfuncstate.

Referenced by ExecProcNode().

{
    TupleTableSlot *result;
    ExprDoneCond isDone;
    ExprContext *econtext;
    int         i;
    int         numfuncs;

    if (winstate->all_done)
        return NULL;

    /*
     * Check to see if we're still projecting out tuples from a previous
     * output tuple (because there is a function-returning-set in the
     * projection expressions).  If so, try to project another one.
     */
    if (winstate->ss.ps.ps_TupFromTlist)
    {
        TupleTableSlot *result;
        ExprDoneCond isDone;

        result = ExecProject(winstate->ss.ps.ps_ProjInfo, &isDone);
        if (isDone == ExprMultipleResult)
            return result;
        /* Done with that source tuple... */
        winstate->ss.ps.ps_TupFromTlist = false;
    }

    /*
     * Compute frame offset values, if any, during first call.
     */
    if (winstate->all_first)
    {
        int         frameOptions = winstate->frameOptions;
        ExprContext *econtext = winstate->ss.ps.ps_ExprContext;
        Datum       value;
        bool        isnull;
        int16       len;
        bool        byval;

        if (frameOptions & FRAMEOPTION_START_VALUE)
        {
            Assert(winstate->startOffset != NULL);
            value = ExecEvalExprSwitchContext(winstate->startOffset,
                                              econtext,
                                              &isnull,
                                              NULL);
            if (isnull)
                ereport(ERROR,
                        (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
                         errmsg("frame starting offset must not be null")));
            /* copy value into query-lifespan context */
            get_typlenbyval(exprType((Node *) winstate->startOffset->expr),
                            &len, &byval);
            winstate->startOffsetValue = datumCopy(value, byval, len);
            if (frameOptions & FRAMEOPTION_ROWS)
            {
                /* value is known to be int8 */
                int64       offset = DatumGetInt64(value);

                if (offset < 0)
                    ereport(ERROR,
                            (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                      errmsg("frame starting offset must not be negative")));
            }
        }
        if (frameOptions & FRAMEOPTION_END_VALUE)
        {
            Assert(winstate->endOffset != NULL);
            value = ExecEvalExprSwitchContext(winstate->endOffset,
                                              econtext,
                                              &isnull,
                                              NULL);
            if (isnull)
                ereport(ERROR,
                        (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
                         errmsg("frame ending offset must not be null")));
            /* copy value into query-lifespan context */
            get_typlenbyval(exprType((Node *) winstate->endOffset->expr),
                            &len, &byval);
            winstate->endOffsetValue = datumCopy(value, byval, len);
            if (frameOptions & FRAMEOPTION_ROWS)
            {
                /* value is known to be int8 */
                int64       offset = DatumGetInt64(value);

                if (offset < 0)
                    ereport(ERROR,
                            (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                        errmsg("frame ending offset must not be negative")));
            }
        }
        winstate->all_first = false;
    }

restart:
    if (winstate->buffer == NULL)
    {
        /* Initialize for first partition and set current row = 0 */
        begin_partition(winstate);
        /* If there are no input rows, we'll detect that and exit below */
    }
    else
    {
        /* Advance current row within partition */
        winstate->currentpos++;
        /* This might mean that the frame moves, too */
        winstate->framehead_valid = false;
        winstate->frametail_valid = false;
    }

    /*
     * Spool all tuples up to and including the current row, if we haven't
     * already
     */
    spool_tuples(winstate, winstate->currentpos);

    /* Move to the next partition if we reached the end of this partition */
    if (winstate->partition_spooled &&
        winstate->currentpos >= winstate->spooled_rows)
    {
        release_partition(winstate);

        if (winstate->more_partitions)
        {
            begin_partition(winstate);
            Assert(winstate->spooled_rows > 0);
        }
        else
        {
            winstate->all_done = true;
            return NULL;
        }
    }

    /* final output execution is in ps_ExprContext */
    econtext = winstate->ss.ps.ps_ExprContext;

    /* Clear the per-output-tuple context for current row */
    ResetExprContext(econtext);

    /*
     * Read the current row from the tuplestore, and save in ScanTupleSlot.
     * (We can't rely on the outerplan's output slot because we may have to
     * read beyond the current row.  Also, we have to actually copy the row
     * out of the tuplestore, since window function evaluation might cause the
     * tuplestore to dump its state to disk.)
     *
     * Current row must be in the tuplestore, since we spooled it above.
     */
    tuplestore_select_read_pointer(winstate->buffer, winstate->current_ptr);
    if (!tuplestore_gettupleslot(winstate->buffer, true, true,
                                 winstate->ss.ss_ScanTupleSlot))
        elog(ERROR, "unexpected end of tuplestore");

    /*
     * Evaluate true window functions
     */
    numfuncs = winstate->numfuncs;
    for (i = 0; i < numfuncs; i++)
    {
        WindowStatePerFunc perfuncstate = &(winstate->perfunc[i]);

        if (perfuncstate->plain_agg)
            continue;
        eval_windowfunction(winstate, perfuncstate,
              &(econtext->ecxt_aggvalues[perfuncstate->wfuncstate->wfuncno]),
              &(econtext->ecxt_aggnulls[perfuncstate->wfuncstate->wfuncno]));
    }

    /*
     * Evaluate aggregates
     */
    if (winstate->numaggs > 0)
        eval_windowaggregates(winstate);

    /*
     * Truncate any no-longer-needed rows from the tuplestore.
     */
    tuplestore_trim(winstate->buffer);

    /*
     * Form and return a projection tuple using the windowfunc results and the
     * current row.  Setting ecxt_outertuple arranges that any Vars will be
     * evaluated with respect to that row.
     */
    econtext->ecxt_outertuple = winstate->ss.ss_ScanTupleSlot;
    result = ExecProject(winstate->ss.ps.ps_ProjInfo, &isDone);

    if (isDone == ExprEndResult)
    {
        /* SRF in tlist returned no rows, so advance to next input tuple */
        goto restart;
    }

    winstate->ss.ps.ps_TupFromTlist =
        (isDone == ExprMultipleResult);
    return result;
}

static void finalize_windowaggregate ( WindowAggState winstate,
WindowStatePerFunc  perfuncstate,
WindowStatePerAgg  peraggstate,
Datum result,
bool isnull 
) [static]

Definition at line 331 of file nodeWindowAgg.c.

References FunctionCallInfoData::arg, FunctionCallInfoData::argnull, CurrentMemoryContext, datumCopy(), DatumGetPointer, ExprContext::ecxt_per_tuple_memory, WindowStatePerAggData::finalfn, WindowStatePerAggData::finalfn_oid, FunctionCallInfoData::flinfo, FmgrInfo::fn_strict, FunctionCallInvoke, InitFunctionCallInfoData, FunctionCallInfoData::isnull, MemoryContextContains(), MemoryContextSwitchTo(), NULL, OidIsValid, ScanState::ps, PlanState::ps_ExprContext, WindowStatePerAggData::resulttypeByVal, WindowStatePerAggData::resulttypeLen, WindowAggState::ss, WindowStatePerAggData::transValue, WindowStatePerAggData::transValueIsNull, and WindowStatePerFuncData::winCollation.

Referenced by eval_windowaggregates().

{
    MemoryContext oldContext;

    oldContext = MemoryContextSwitchTo(winstate->ss.ps.ps_ExprContext->ecxt_per_tuple_memory);

    /*
     * Apply the agg's finalfn if one is provided, else return transValue.
     */
    if (OidIsValid(peraggstate->finalfn_oid))
    {
        FunctionCallInfoData fcinfo;

        InitFunctionCallInfoData(fcinfo, &(peraggstate->finalfn), 1,
                                 perfuncstate->winCollation,
                                 (void *) winstate, NULL);
        fcinfo.arg[0] = peraggstate->transValue;
        fcinfo.argnull[0] = peraggstate->transValueIsNull;
        if (fcinfo.flinfo->fn_strict && peraggstate->transValueIsNull)
        {
            /* don't call a strict function with NULL inputs */
            *result = (Datum) 0;
            *isnull = true;
        }
        else
        {
            *result = FunctionCallInvoke(&fcinfo);
            *isnull = fcinfo.isnull;
        }
    }
    else
    {
        *result = peraggstate->transValue;
        *isnull = peraggstate->transValueIsNull;
    }

    /*
     * If result is pass-by-ref, make sure it is in the right context.
     */
    if (!peraggstate->resulttypeByVal && !*isnull &&
        !MemoryContextContains(CurrentMemoryContext,
                               DatumGetPointer(*result)))
        *result = datumCopy(*result,
                            peraggstate->resulttypeByVal,
                            peraggstate->resulttypeLen);
    MemoryContextSwitchTo(oldContext);
}

static Datum GetAggInitVal ( Datum  textInitVal,
Oid  transtype 
) [static]

Definition at line 1866 of file nodeWindowAgg.c.

References getTypeInputInfo(), OidInputFunctionCall(), pfree(), and TextDatumGetCString.

Referenced by initialize_peragg().

{
    Oid         typinput,
                typioparam;
    char       *strInitVal;
    Datum       initVal;

    getTypeInputInfo(transtype, &typinput, &typioparam);
    strInitVal = TextDatumGetCString(textInitVal);
    initVal = OidInputFunctionCall(typinput, strInitVal,
                                   typioparam, -1);
    pfree(strInitVal);
    return initVal;
}

static WindowStatePerAggData * initialize_peragg ( WindowAggState winstate,
WindowFunc wfunc,
WindowStatePerAgg  peraggstate 
) [static]

Definition at line 1715 of file nodeWindowAgg.c.

References ACL_EXECUTE, ACL_KIND_PROC, aclcheck_error(), ACLCHECK_OK, AGGFNOID, Anum_pg_aggregate_agginitval, WindowFunc::args, Assert, build_aggregate_fnexprs(), elog, enforce_generic_type_consistency(), ereport, errcode(), errmsg(), ERROR, exprType(), WindowStatePerAggData::finalfn, WindowStatePerAggData::finalfn_oid, fmgr_info(), fmgr_info_set_expr, FmgrInfo::fn_strict, get_func_name(), get_func_signature(), get_typlenbyval(), GetAggInitVal(), GETSTRUCT, HeapTupleIsValid, i, WindowStatePerAggData::initValue, WindowStatePerAggData::initValueIsNull, WindowFunc::inputcollid, InvokeFunctionExecuteHook, IsBinaryCoercible(), IsPolymorphicType, lfirst, list_length(), ObjectIdGetDatum, OidIsValid, pfree(), pg_proc_aclcheck(), PROCOID, ReleaseSysCache(), WindowStatePerAggData::resulttypeByVal, WindowStatePerAggData::resulttypeLen, SearchSysCache1, SysCacheGetAttr(), WindowStatePerAggData::transfn, WindowStatePerAggData::transfn_oid, WindowStatePerAggData::transtypeByVal, WindowStatePerAggData::transtypeLen, WindowFunc::winfnoid, and WindowFunc::wintype.

Referenced by ExecInitWindowAgg().

{
    Oid         inputTypes[FUNC_MAX_ARGS];
    int         numArguments;
    HeapTuple   aggTuple;
    Form_pg_aggregate aggform;
    Oid         aggtranstype;
    AclResult   aclresult;
    Oid         transfn_oid,
                finalfn_oid;
    Expr       *transfnexpr,
               *finalfnexpr;
    Datum       textInitVal;
    int         i;
    ListCell   *lc;

    numArguments = list_length(wfunc->args);

    i = 0;
    foreach(lc, wfunc->args)
    {
        inputTypes[i++] = exprType((Node *) lfirst(lc));
    }

    aggTuple = SearchSysCache1(AGGFNOID, ObjectIdGetDatum(wfunc->winfnoid));
    if (!HeapTupleIsValid(aggTuple))
        elog(ERROR, "cache lookup failed for aggregate %u",
             wfunc->winfnoid);
    aggform = (Form_pg_aggregate) GETSTRUCT(aggTuple);

    /*
     * ExecInitWindowAgg already checked permission to call aggregate function
     * ... but we still need to check the component functions
     */

    peraggstate->transfn_oid = transfn_oid = aggform->aggtransfn;
    peraggstate->finalfn_oid = finalfn_oid = aggform->aggfinalfn;

    /* Check that aggregate owner has permission to call component fns */
    {
        HeapTuple   procTuple;
        Oid         aggOwner;

        procTuple = SearchSysCache1(PROCOID,
                                    ObjectIdGetDatum(wfunc->winfnoid));
        if (!HeapTupleIsValid(procTuple))
            elog(ERROR, "cache lookup failed for function %u",
                 wfunc->winfnoid);
        aggOwner = ((Form_pg_proc) GETSTRUCT(procTuple))->proowner;
        ReleaseSysCache(procTuple);

        aclresult = pg_proc_aclcheck(transfn_oid, aggOwner,
                                     ACL_EXECUTE);
        if (aclresult != ACLCHECK_OK)
            aclcheck_error(aclresult, ACL_KIND_PROC,
                           get_func_name(transfn_oid));
        InvokeFunctionExecuteHook(transfn_oid);
        if (OidIsValid(finalfn_oid))
        {
            aclresult = pg_proc_aclcheck(finalfn_oid, aggOwner,
                                         ACL_EXECUTE);
            if (aclresult != ACLCHECK_OK)
                aclcheck_error(aclresult, ACL_KIND_PROC,
                               get_func_name(finalfn_oid));
            InvokeFunctionExecuteHook(finalfn_oid);
        }
    }

    /* resolve actual type of transition state, if polymorphic */
    aggtranstype = aggform->aggtranstype;
    if (IsPolymorphicType(aggtranstype))
    {
        /* have to fetch the agg's declared input types... */
        Oid        *declaredArgTypes;
        int         agg_nargs;

        get_func_signature(wfunc->winfnoid,
                           &declaredArgTypes, &agg_nargs);
        Assert(agg_nargs == numArguments);
        aggtranstype = enforce_generic_type_consistency(inputTypes,
                                                        declaredArgTypes,
                                                        agg_nargs,
                                                        aggtranstype,
                                                        false);
        pfree(declaredArgTypes);
    }

    /* build expression trees using actual argument & result types */
    build_aggregate_fnexprs(inputTypes,
                            numArguments,
                            aggtranstype,
                            wfunc->wintype,
                            wfunc->inputcollid,
                            transfn_oid,
                            finalfn_oid,
                            &transfnexpr,
                            &finalfnexpr);

    fmgr_info(transfn_oid, &peraggstate->transfn);
    fmgr_info_set_expr((Node *) transfnexpr, &peraggstate->transfn);

    if (OidIsValid(finalfn_oid))
    {
        fmgr_info(finalfn_oid, &peraggstate->finalfn);
        fmgr_info_set_expr((Node *) finalfnexpr, &peraggstate->finalfn);
    }

    get_typlenbyval(wfunc->wintype,
                    &peraggstate->resulttypeLen,
                    &peraggstate->resulttypeByVal);
    get_typlenbyval(aggtranstype,
                    &peraggstate->transtypeLen,
                    &peraggstate->transtypeByVal);

    /*
     * initval is potentially null, so don't try to access it as a struct
     * field. Must do it the hard way with SysCacheGetAttr.
     */
    textInitVal = SysCacheGetAttr(AGGFNOID, aggTuple,
                                  Anum_pg_aggregate_agginitval,
                                  &peraggstate->initValueIsNull);

    if (peraggstate->initValueIsNull)
        peraggstate->initValue = (Datum) 0;
    else
        peraggstate->initValue = GetAggInitVal(textInitVal,
                                               aggtranstype);

    /*
     * If the transfn is strict and the initval is NULL, make sure input type
     * and transtype are the same (or at least binary-compatible), so that
     * it's OK to use the first input value as the initial transValue.  This
     * should have been checked at agg definition time, but just in case...
     */
    if (peraggstate->transfn.fn_strict && peraggstate->initValueIsNull)
    {
        if (numArguments < 1 ||
            !IsBinaryCoercible(inputTypes[0], aggtranstype))
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                     errmsg("aggregate %u needs to have compatible input type and transition type",
                            wfunc->winfnoid)));
    }

    ReleaseSysCache(aggTuple);

    return peraggstate;
}

static void initialize_windowaggregate ( WindowAggState winstate,
WindowStatePerFunc  perfuncstate,
WindowStatePerAgg  peraggstate 
) [static]
static void release_partition ( WindowAggState winstate  )  [static]

Definition at line 839 of file nodeWindowAgg.c.

References WindowAggState::aggcontext, WindowAggState::buffer, i, WindowObjectData::localmem, MemoryContextResetAndDeleteChildren(), WindowAggState::numfuncs, WindowAggState::partcontext, WindowAggState::partition_spooled, WindowAggState::perfunc, tuplestore_end(), and WindowStatePerFuncData::winobj.

Referenced by ExecEndWindowAgg(), ExecReScanWindowAgg(), and ExecWindowAgg().

{
    int         i;

    for (i = 0; i < winstate->numfuncs; i++)
    {
        WindowStatePerFunc perfuncstate = &(winstate->perfunc[i]);

        /* Release any partition-local state of this window function */
        if (perfuncstate->winobj)
            perfuncstate->winobj->localmem = NULL;
    }

    /*
     * Release all partition-local memory (in particular, any partition-local
     * state that we might have trashed our pointers to in the above loop, and
     * any aggregate temp data).  We don't rely on retail pfree because some
     * aggregates might have allocated data we don't have direct pointers to.
     */
    MemoryContextResetAndDeleteChildren(winstate->partcontext);
    MemoryContextResetAndDeleteChildren(winstate->aggcontext);

    if (winstate->buffer)
        tuplestore_end(winstate->buffer);
    winstate->buffer = NULL;
    winstate->partition_spooled = false;
}

static bool row_is_in_frame ( WindowAggState winstate,
int64  pos,
TupleTableSlot slot 
) [static]

Definition at line 877 of file nodeWindowAgg.c.

References are_peers(), Assert, WindowAggState::currentpos, DatumGetInt64, elog, WindowAggState::endOffsetValue, ERROR, FRAMEOPTION_END_CURRENT_ROW, FRAMEOPTION_END_VALUE, FRAMEOPTION_END_VALUE_PRECEDING, FRAMEOPTION_RANGE, FRAMEOPTION_ROWS, FRAMEOPTION_START_CURRENT_ROW, FRAMEOPTION_START_VALUE, FRAMEOPTION_START_VALUE_PRECEDING, WindowAggState::frameOptions, WindowAggState::ss, ScanState::ss_ScanTupleSlot, and WindowAggState::startOffsetValue.

Referenced by eval_windowaggregates(), and WinGetFuncArgInFrame().

{
    int         frameOptions = winstate->frameOptions;

    Assert(pos >= 0);           /* else caller error */

    /* First, check frame starting conditions */
    if (frameOptions & FRAMEOPTION_START_CURRENT_ROW)
    {
        if (frameOptions & FRAMEOPTION_ROWS)
        {
            /* rows before current row are out of frame */
            if (pos < winstate->currentpos)
                return false;
        }
        else if (frameOptions & FRAMEOPTION_RANGE)
        {
            /* preceding row that is not peer is out of frame */
            if (pos < winstate->currentpos &&
                !are_peers(winstate, slot, winstate->ss.ss_ScanTupleSlot))
                return false;
        }
        else
            Assert(false);
    }
    else if (frameOptions & FRAMEOPTION_START_VALUE)
    {
        if (frameOptions & FRAMEOPTION_ROWS)
        {
            int64       offset = DatumGetInt64(winstate->startOffsetValue);

            /* rows before current row + offset are out of frame */
            if (frameOptions & FRAMEOPTION_START_VALUE_PRECEDING)
                offset = -offset;

            if (pos < winstate->currentpos + offset)
                return false;
        }
        else if (frameOptions & FRAMEOPTION_RANGE)
        {
            /* parser should have rejected this */
            elog(ERROR, "window frame with value offset is not implemented");
        }
        else
            Assert(false);
    }

    /* Okay so far, now check frame ending conditions */
    if (frameOptions & FRAMEOPTION_END_CURRENT_ROW)
    {
        if (frameOptions & FRAMEOPTION_ROWS)
        {
            /* rows after current row are out of frame */
            if (pos > winstate->currentpos)
                return false;
        }
        else if (frameOptions & FRAMEOPTION_RANGE)
        {
            /* following row that is not peer is out of frame */
            if (pos > winstate->currentpos &&
                !are_peers(winstate, slot, winstate->ss.ss_ScanTupleSlot))
                return false;
        }
        else
            Assert(false);
    }
    else if (frameOptions & FRAMEOPTION_END_VALUE)
    {
        if (frameOptions & FRAMEOPTION_ROWS)
        {
            int64       offset = DatumGetInt64(winstate->endOffsetValue);

            /* rows after current row + offset are out of frame */
            if (frameOptions & FRAMEOPTION_END_VALUE_PRECEDING)
                offset = -offset;

            if (pos > winstate->currentpos + offset)
                return false;
        }
        else if (frameOptions & FRAMEOPTION_RANGE)
        {
            /* parser should have rejected this */
            elog(ERROR, "window frame with value offset is not implemented");
        }
        else
            Assert(false);
    }

    /* If we get here, it's in frame */
    return true;
}

static void spool_tuples ( WindowAggState winstate,
int64  pos 
) [static]

Definition at line 767 of file nodeWindowAgg.c.

References WindowAggState::buffer, ExprContext::ecxt_per_query_memory, ExprContext::ecxt_per_tuple_memory, ExecCopySlot(), ExecProcNode(), execTuplesMatch(), WindowAggState::first_part_slot, MemoryContextSwitchTo(), WindowAggState::more_partitions, outerPlan, outerPlanState, WindowAgg::partColIdx, WindowAggState::partEqfunctions, WindowAggState::partition_spooled, WindowAgg::partNumCols, PlanState::plan, ScanState::ps, PlanState::ps_ExprContext, WindowAggState::spooled_rows, WindowAggState::ss, WindowAggState::tmpcontext, TupIsNull, tuplestore_in_memory(), and tuplestore_puttupleslot().

Referenced by ExecWindowAgg(), update_frameheadpos(), update_frametailpos(), window_gettupleslot(), WinGetFuncArgInPartition(), and WinGetPartitionRowCount().

{
    WindowAgg  *node = (WindowAgg *) winstate->ss.ps.plan;
    PlanState  *outerPlan;
    TupleTableSlot *outerslot;
    MemoryContext oldcontext;

    if (!winstate->buffer)
        return;                 /* just a safety check */
    if (winstate->partition_spooled)
        return;                 /* whole partition done already */

    /*
     * If the tuplestore has spilled to disk, alternate reading and writing
     * becomes quite expensive due to frequent buffer flushes.  It's cheaper
     * to force the entire partition to get spooled in one go.
     *
     * XXX this is a horrid kluge --- it'd be better to fix the performance
     * problem inside tuplestore.  FIXME
     */
    if (!tuplestore_in_memory(winstate->buffer))
        pos = -1;

    outerPlan = outerPlanState(winstate);

    /* Must be in query context to call outerplan */
    oldcontext = MemoryContextSwitchTo(winstate->ss.ps.ps_ExprContext->ecxt_per_query_memory);

    while (winstate->spooled_rows <= pos || pos == -1)
    {
        outerslot = ExecProcNode(outerPlan);
        if (TupIsNull(outerslot))
        {
            /* reached the end of the last partition */
            winstate->partition_spooled = true;
            winstate->more_partitions = false;
            break;
        }

        if (node->partNumCols > 0)
        {
            /* Check if this tuple still belongs to the current partition */
            if (!execTuplesMatch(winstate->first_part_slot,
                                 outerslot,
                                 node->partNumCols, node->partColIdx,
                                 winstate->partEqfunctions,
                                 winstate->tmpcontext->ecxt_per_tuple_memory))
            {
                /*
                 * end of partition; copy the tuple for the next cycle.
                 */
                ExecCopySlot(winstate->first_part_slot, outerslot);
                winstate->partition_spooled = true;
                winstate->more_partitions = true;
                break;
            }
        }

        /* Still in partition, so save it into the tuplestore */
        tuplestore_puttupleslot(winstate->buffer, outerslot);
        winstate->spooled_rows++;
    }

    MemoryContextSwitchTo(oldcontext);
}

static void update_frameheadpos ( WindowObject  winobj,
TupleTableSlot slot 
) [static]

Definition at line 979 of file nodeWindowAgg.c.

References are_peers(), Assert, WindowAggState::currentpos, DatumGetInt64, elog, ERROR, WindowAggState::framehead_valid, WindowAggState::frameheadpos, FRAMEOPTION_RANGE, FRAMEOPTION_ROWS, FRAMEOPTION_START_CURRENT_ROW, FRAMEOPTION_START_UNBOUNDED_PRECEDING, FRAMEOPTION_START_VALUE, FRAMEOPTION_START_VALUE_PRECEDING, WindowAggState::frameOptions, WindowAgg::ordNumCols, PlanState::plan, ScanState::ps, spool_tuples(), WindowAggState::spooled_rows, WindowAggState::ss, ScanState::ss_ScanTupleSlot, WindowAggState::startOffsetValue, window_gettupleslot(), and WindowObjectData::winstate.

Referenced by eval_windowaggregates(), WinGetFuncArgInFrame(), and WinGetFuncArgInPartition().

{
    WindowAggState *winstate = winobj->winstate;
    WindowAgg  *node = (WindowAgg *) winstate->ss.ps.plan;
    int         frameOptions = winstate->frameOptions;

    if (winstate->framehead_valid)
        return;                 /* already known for current row */

    if (frameOptions & FRAMEOPTION_START_UNBOUNDED_PRECEDING)
    {
        /* In UNBOUNDED PRECEDING mode, frame head is always row 0 */
        winstate->frameheadpos = 0;
        winstate->framehead_valid = true;
    }
    else if (frameOptions & FRAMEOPTION_START_CURRENT_ROW)
    {
        if (frameOptions & FRAMEOPTION_ROWS)
        {
            /* In ROWS mode, frame head is the same as current */
            winstate->frameheadpos = winstate->currentpos;
            winstate->framehead_valid = true;
        }
        else if (frameOptions & FRAMEOPTION_RANGE)
        {
            int64       fhprev;

            /* If no ORDER BY, all rows are peers with each other */
            if (node->ordNumCols == 0)
            {
                winstate->frameheadpos = 0;
                winstate->framehead_valid = true;
                return;
            }

            /*
             * In RANGE START_CURRENT mode, frame head is the first row that
             * is a peer of current row.  We search backwards from current,
             * which could be a bit inefficient if peer sets are large. Might
             * be better to have a separate read pointer that moves forward
             * tracking the frame head.
             */
            fhprev = winstate->currentpos - 1;
            for (;;)
            {
                /* assume the frame head can't go backwards */
                if (fhprev < winstate->frameheadpos)
                    break;
                if (!window_gettupleslot(winobj, fhprev, slot))
                    break;      /* start of partition */
                if (!are_peers(winstate, slot, winstate->ss.ss_ScanTupleSlot))
                    break;      /* not peer of current row */
                fhprev--;
            }
            winstate->frameheadpos = fhprev + 1;
            winstate->framehead_valid = true;
        }
        else
            Assert(false);
    }
    else if (frameOptions & FRAMEOPTION_START_VALUE)
    {
        if (frameOptions & FRAMEOPTION_ROWS)
        {
            /* In ROWS mode, bound is physically n before/after current */
            int64       offset = DatumGetInt64(winstate->startOffsetValue);

            if (frameOptions & FRAMEOPTION_START_VALUE_PRECEDING)
                offset = -offset;

            winstate->frameheadpos = winstate->currentpos + offset;
            /* frame head can't go before first row */
            if (winstate->frameheadpos < 0)
                winstate->frameheadpos = 0;
            else if (winstate->frameheadpos > winstate->currentpos)
            {
                /* make sure frameheadpos is not past end of partition */
                spool_tuples(winstate, winstate->frameheadpos - 1);
                if (winstate->frameheadpos > winstate->spooled_rows)
                    winstate->frameheadpos = winstate->spooled_rows;
            }
            winstate->framehead_valid = true;
        }
        else if (frameOptions & FRAMEOPTION_RANGE)
        {
            /* parser should have rejected this */
            elog(ERROR, "window frame with value offset is not implemented");
        }
        else
            Assert(false);
    }
    else
        Assert(false);
}

static void update_frametailpos ( WindowObject  winobj,
TupleTableSlot slot 
) [static]

Definition at line 1084 of file nodeWindowAgg.c.

References are_peers(), Assert, WindowAggState::currentpos, DatumGetInt64, elog, WindowAggState::endOffsetValue, ERROR, FRAMEOPTION_END_CURRENT_ROW, FRAMEOPTION_END_UNBOUNDED_FOLLOWING, FRAMEOPTION_END_VALUE, FRAMEOPTION_END_VALUE_PRECEDING, FRAMEOPTION_RANGE, FRAMEOPTION_ROWS, WindowAggState::frameOptions, WindowAggState::frametail_valid, WindowAggState::frametailpos, Max, WindowAgg::ordNumCols, PlanState::plan, ScanState::ps, spool_tuples(), WindowAggState::spooled_rows, WindowAggState::ss, ScanState::ss_ScanTupleSlot, window_gettupleslot(), and WindowObjectData::winstate.

Referenced by WinGetFuncArgInFrame().

{
    WindowAggState *winstate = winobj->winstate;
    WindowAgg  *node = (WindowAgg *) winstate->ss.ps.plan;
    int         frameOptions = winstate->frameOptions;

    if (winstate->frametail_valid)
        return;                 /* already known for current row */

    if (frameOptions & FRAMEOPTION_END_UNBOUNDED_FOLLOWING)
    {
        /* In UNBOUNDED FOLLOWING mode, all partition rows are in frame */
        spool_tuples(winstate, -1);
        winstate->frametailpos = winstate->spooled_rows - 1;
        winstate->frametail_valid = true;
    }
    else if (frameOptions & FRAMEOPTION_END_CURRENT_ROW)
    {
        if (frameOptions & FRAMEOPTION_ROWS)
        {
            /* In ROWS mode, exactly the rows up to current are in frame */
            winstate->frametailpos = winstate->currentpos;
            winstate->frametail_valid = true;
        }
        else if (frameOptions & FRAMEOPTION_RANGE)
        {
            int64       ftnext;

            /* If no ORDER BY, all rows are peers with each other */
            if (node->ordNumCols == 0)
            {
                spool_tuples(winstate, -1);
                winstate->frametailpos = winstate->spooled_rows - 1;
                winstate->frametail_valid = true;
                return;
            }

            /*
             * Else we have to search for the first non-peer of the current
             * row.  We assume the current value of frametailpos is a lower
             * bound on the possible frame tail location, ie, frame tail never
             * goes backward, and that currentpos is also a lower bound, ie,
             * frame end always >= current row.
             */
            ftnext = Max(winstate->frametailpos, winstate->currentpos) + 1;
            for (;;)
            {
                if (!window_gettupleslot(winobj, ftnext, slot))
                    break;      /* end of partition */
                if (!are_peers(winstate, slot, winstate->ss.ss_ScanTupleSlot))
                    break;      /* not peer of current row */
                ftnext++;
            }
            winstate->frametailpos = ftnext - 1;
            winstate->frametail_valid = true;
        }
        else
            Assert(false);
    }
    else if (frameOptions & FRAMEOPTION_END_VALUE)
    {
        if (frameOptions & FRAMEOPTION_ROWS)
        {
            /* In ROWS mode, bound is physically n before/after current */
            int64       offset = DatumGetInt64(winstate->endOffsetValue);

            if (frameOptions & FRAMEOPTION_END_VALUE_PRECEDING)
                offset = -offset;

            winstate->frametailpos = winstate->currentpos + offset;
            /* smallest allowable value of frametailpos is -1 */
            if (winstate->frametailpos < 0)
                winstate->frametailpos = -1;
            else if (winstate->frametailpos > winstate->currentpos)
            {
                /* make sure frametailpos is not past last row of partition */
                spool_tuples(winstate, winstate->frametailpos);
                if (winstate->frametailpos >= winstate->spooled_rows)
                    winstate->frametailpos = winstate->spooled_rows - 1;
            }
            winstate->frametail_valid = true;
        }
        else if (frameOptions & FRAMEOPTION_RANGE)
        {
            /* parser should have rejected this */
            elog(ERROR, "window frame with value offset is not implemented");
        }
        else
            Assert(false);
    }
    else
        Assert(false);
}

static bool window_gettupleslot ( WindowObject  winobj,
int64  pos,
TupleTableSlot slot 
) [static]

Definition at line 1911 of file nodeWindowAgg.c.

References WindowAggState::buffer, ExprContext::ecxt_per_query_memory, elog, ERROR, MemoryContextSwitchTo(), ScanState::ps, PlanState::ps_ExprContext, WindowObjectData::readptr, WindowObjectData::seekpos, spool_tuples(), WindowAggState::spooled_rows, WindowAggState::ss, tuplestore_advance(), tuplestore_gettupleslot(), tuplestore_select_read_pointer(), and WindowObjectData::winstate.

Referenced by eval_windowaggregates(), update_frameheadpos(), update_frametailpos(), WinGetFuncArgInFrame(), WinGetFuncArgInPartition(), and WinRowsArePeers().

{
    WindowAggState *winstate = winobj->winstate;
    MemoryContext oldcontext;

    /* Don't allow passing -1 to spool_tuples here */
    if (pos < 0)
        return false;

    /* If necessary, fetch the tuple into the spool */
    spool_tuples(winstate, pos);

    if (pos >= winstate->spooled_rows)
        return false;

    if (pos < winobj->markpos)
        elog(ERROR, "cannot fetch row before WindowObject's mark position");

    oldcontext = MemoryContextSwitchTo(winstate->ss.ps.ps_ExprContext->ecxt_per_query_memory);

    tuplestore_select_read_pointer(winstate->buffer, winobj->readptr);

    /*
     * There's no API to refetch the tuple at the current position. We have to
     * move one tuple forward, and then one backward.  (We don't do it the
     * other way because we might try to fetch the row before our mark, which
     * isn't allowed.)  XXX this case could stand to be optimized.
     */
    if (winobj->seekpos == pos)
    {
        tuplestore_advance(winstate->buffer, true);
        winobj->seekpos++;
    }

    while (winobj->seekpos > pos)
    {
        if (!tuplestore_gettupleslot(winstate->buffer, false, true, slot))
            elog(ERROR, "unexpected end of tuplestore");
        winobj->seekpos--;
    }

    while (winobj->seekpos < pos)
    {
        if (!tuplestore_gettupleslot(winstate->buffer, true, true, slot))
            elog(ERROR, "unexpected end of tuplestore");
        winobj->seekpos++;
    }

    MemoryContextSwitchTo(oldcontext);

    return true;
}

int64 WinGetCurrentPosition ( WindowObject  winobj  ) 
Datum WinGetFuncArgCurrent ( WindowObject  winobj,
int  argno,
bool isnull 
)
Datum WinGetFuncArgInFrame ( WindowObject  winobj,
int  argno,
int  relpos,
int  seektype,
bool  set_mark,
bool isnull,
bool isout 
)

Definition at line 2211 of file nodeWindowAgg.c.

References WindowObjectData::argstates, Assert, WindowAggState::currentpos, ExprContext::ecxt_outertuple, elog, ERROR, ExecEvalExpr, WindowAggState::frameheadpos, FRAMEOPTION_RANGE, FRAMEOPTION_START_UNBOUNDED_PRECEDING, WindowAggState::frameOptions, WindowAggState::frametailpos, list_nth(), NULL, ScanState::ps, PlanState::ps_ExprContext, row_is_in_frame(), WindowAggState::ss, WindowAggState::temp_slot_1, WindowAggState::temp_slot_2, update_frameheadpos(), update_frametailpos(), window_gettupleslot(), WINDOW_SEEK_CURRENT, WINDOW_SEEK_HEAD, WINDOW_SEEK_TAIL, WindowObjectIsValid, WinSetMarkPosition(), and WindowObjectData::winstate.

Referenced by window_first_value(), window_last_value(), and window_nth_value().

{
    WindowAggState *winstate;
    ExprContext *econtext;
    TupleTableSlot *slot;
    bool        gottuple;
    int64       abs_pos;

    Assert(WindowObjectIsValid(winobj));
    winstate = winobj->winstate;
    econtext = winstate->ss.ps.ps_ExprContext;
    slot = winstate->temp_slot_1;

    switch (seektype)
    {
        case WINDOW_SEEK_CURRENT:
            abs_pos = winstate->currentpos + relpos;
            break;
        case WINDOW_SEEK_HEAD:
            update_frameheadpos(winobj, slot);
            abs_pos = winstate->frameheadpos + relpos;
            break;
        case WINDOW_SEEK_TAIL:
            update_frametailpos(winobj, slot);
            abs_pos = winstate->frametailpos + relpos;
            break;
        default:
            elog(ERROR, "unrecognized window seek type: %d", seektype);
            abs_pos = 0;        /* keep compiler quiet */
            break;
    }

    gottuple = window_gettupleslot(winobj, abs_pos, slot);
    if (gottuple)
        gottuple = row_is_in_frame(winstate, abs_pos, slot);

    if (!gottuple)
    {
        if (isout)
            *isout = true;
        *isnull = true;
        return (Datum) 0;
    }
    else
    {
        if (isout)
            *isout = false;
        if (set_mark)
        {
            int         frameOptions = winstate->frameOptions;
            int64       mark_pos = abs_pos;

            /*
             * In RANGE mode with a moving frame head, we must not let the
             * mark advance past frameheadpos, since that row has to be
             * fetchable during future update_frameheadpos calls.
             *
             * XXX it is very ugly to pollute window functions' marks with
             * this consideration; it could for instance mask a logic bug that
             * lets a window function fetch rows before what it had claimed
             * was its mark.  Perhaps use a separate mark for frame head
             * probes?
             */
            if ((frameOptions & FRAMEOPTION_RANGE) &&
                !(frameOptions & FRAMEOPTION_START_UNBOUNDED_PRECEDING))
            {
                update_frameheadpos(winobj, winstate->temp_slot_2);
                if (mark_pos > winstate->frameheadpos)
                    mark_pos = winstate->frameheadpos;
            }
            WinSetMarkPosition(winobj, mark_pos);
        }
        econtext->ecxt_outertuple = slot;
        return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno),
                            econtext, isnull, NULL);
    }
}

Datum WinGetFuncArgInPartition ( WindowObject  winobj,
int  argno,
int  relpos,
int  seektype,
bool  set_mark,
bool isnull,
bool isout 
)

Definition at line 2115 of file nodeWindowAgg.c.

References WindowObjectData::argstates, Assert, WindowAggState::currentpos, ExprContext::ecxt_outertuple, elog, ERROR, ExecEvalExpr, WindowAggState::frameheadpos, FRAMEOPTION_RANGE, FRAMEOPTION_START_UNBOUNDED_PRECEDING, WindowAggState::frameOptions, list_nth(), NULL, ScanState::ps, PlanState::ps_ExprContext, spool_tuples(), WindowAggState::spooled_rows, WindowAggState::ss, WindowAggState::temp_slot_1, WindowAggState::temp_slot_2, update_frameheadpos(), window_gettupleslot(), WINDOW_SEEK_CURRENT, WINDOW_SEEK_HEAD, WINDOW_SEEK_TAIL, WindowObjectIsValid, WinSetMarkPosition(), and WindowObjectData::winstate.

Referenced by leadlag_common().

{
    WindowAggState *winstate;
    ExprContext *econtext;
    TupleTableSlot *slot;
    bool        gottuple;
    int64       abs_pos;

    Assert(WindowObjectIsValid(winobj));
    winstate = winobj->winstate;
    econtext = winstate->ss.ps.ps_ExprContext;
    slot = winstate->temp_slot_1;

    switch (seektype)
    {
        case WINDOW_SEEK_CURRENT:
            abs_pos = winstate->currentpos + relpos;
            break;
        case WINDOW_SEEK_HEAD:
            abs_pos = relpos;
            break;
        case WINDOW_SEEK_TAIL:
            spool_tuples(winstate, -1);
            abs_pos = winstate->spooled_rows - 1 + relpos;
            break;
        default:
            elog(ERROR, "unrecognized window seek type: %d", seektype);
            abs_pos = 0;        /* keep compiler quiet */
            break;
    }

    gottuple = window_gettupleslot(winobj, abs_pos, slot);

    if (!gottuple)
    {
        if (isout)
            *isout = true;
        *isnull = true;
        return (Datum) 0;
    }
    else
    {
        if (isout)
            *isout = false;
        if (set_mark)
        {
            int         frameOptions = winstate->frameOptions;
            int64       mark_pos = abs_pos;

            /*
             * In RANGE mode with a moving frame head, we must not let the
             * mark advance past frameheadpos, since that row has to be
             * fetchable during future update_frameheadpos calls.
             *
             * XXX it is very ugly to pollute window functions' marks with
             * this consideration; it could for instance mask a logic bug that
             * lets a window function fetch rows before what it had claimed
             * was its mark.  Perhaps use a separate mark for frame head
             * probes?
             */
            if ((frameOptions & FRAMEOPTION_RANGE) &&
                !(frameOptions & FRAMEOPTION_START_UNBOUNDED_PRECEDING))
            {
                update_frameheadpos(winobj, winstate->temp_slot_2);
                if (mark_pos > winstate->frameheadpos)
                    mark_pos = winstate->frameheadpos;
            }
            WinSetMarkPosition(winobj, mark_pos);
        }
        econtext->ecxt_outertuple = slot;
        return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno),
                            econtext, isnull, NULL);
    }
}

void* WinGetPartitionLocalMemory ( WindowObject  winobj,
Size  sz 
)
int64 WinGetPartitionRowCount ( WindowObject  winobj  ) 
bool WinRowsArePeers ( WindowObject  winobj,
int64  pos1,
int64  pos2 
)

Definition at line 2062 of file nodeWindowAgg.c.

References are_peers(), Assert, elog, ERROR, ExecClearTuple(), WindowAgg::ordNumCols, PlanState::plan, ScanState::ps, WindowAggState::ss, WindowAggState::temp_slot_1, WindowAggState::temp_slot_2, window_gettupleslot(), WindowObjectIsValid, and WindowObjectData::winstate.

Referenced by rank_up(), and window_cume_dist().

{
    WindowAggState *winstate;
    WindowAgg  *node;
    TupleTableSlot *slot1;
    TupleTableSlot *slot2;
    bool        res;

    Assert(WindowObjectIsValid(winobj));
    winstate = winobj->winstate;
    node = (WindowAgg *) winstate->ss.ps.plan;

    /* If no ORDER BY, all rows are peers; don't bother to fetch them */
    if (node->ordNumCols == 0)
        return true;

    slot1 = winstate->temp_slot_1;
    slot2 = winstate->temp_slot_2;

    if (!window_gettupleslot(winobj, pos1, slot1))
        elog(ERROR, "specified position is out of window: " INT64_FORMAT,
             pos1);
    if (!window_gettupleslot(winobj, pos2, slot2))
        elog(ERROR, "specified position is out of window: " INT64_FORMAT,
             pos2);

    res = are_peers(winstate, slot1, slot2);

    ExecClearTuple(slot1);
    ExecClearTuple(slot2);

    return res;
}

void WinSetMarkPosition ( WindowObject  winobj,
int64  markpos 
)

Definition at line 2031 of file nodeWindowAgg.c.

References Assert, WindowAggState::buffer, elog, ERROR, WindowObjectData::markpos, WindowObjectData::markptr, WindowObjectData::readptr, WindowObjectData::seekpos, tuplestore_advance(), tuplestore_select_read_pointer(), WindowObjectIsValid, and WindowObjectData::winstate.

Referenced by eval_windowaggregates(), rank_up(), window_row_number(), WinGetFuncArgInFrame(), and WinGetFuncArgInPartition().

{
    WindowAggState *winstate;

    Assert(WindowObjectIsValid(winobj));
    winstate = winobj->winstate;

    if (markpos < winobj->markpos)
        elog(ERROR, "cannot move WindowObject's mark position backward");
    tuplestore_select_read_pointer(winstate->buffer, winobj->markptr);
    while (markpos > winobj->markpos)
    {
        tuplestore_advance(winstate->buffer, true);
        winobj->markpos++;
    }
    tuplestore_select_read_pointer(winstate->buffer, winobj->readptr);
    while (markpos > winobj->seekpos)
    {
        tuplestore_advance(winstate->buffer, true);
        winobj->seekpos++;
    }
}