pg_collation_fn.h File Reference

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Functions
Oid	CollationCreate (const char *collname, Oid collnamespace, Oid collowner, int32 collencoding, const char *collcollate, const char *collctype)
void	RemoveCollationById (Oid collationOid)

---

Function Documentation

Oid CollationCreate	(	const char *	collname,
		Oid	collnamespace,
		Oid	collowner,
		int32	collencoding,
		const char *	collcollate,
		const char *	collctype
	)

Definition at line 41 of file pg_collation.c.

References Anum_pg_collation_collcollate, Anum_pg_collation_collctype, Anum_pg_collation_collencoding, Anum_pg_collation_collname, Anum_pg_collation_collnamespace, Anum_pg_collation_collowner, Assert, AssertArg, CatalogUpdateIndexes(), ObjectAddress::classId, CollationRelationId, COLLNAMEENCNSP, DEPENDENCY_NORMAL, ereport, errcode(), errmsg(), ERROR, heap_close, heap_form_tuple(), heap_freetuple(), heap_open(), HeapTupleGetOid, Int32GetDatum, InvokeObjectPostCreateHook, NameGetDatum, namestrcpy(), ObjectAddress::objectId, ObjectIdGetDatum, ObjectAddress::objectSubId, OidIsValid, pg_encoding_to_char(), PointerGetDatum, recordDependencyOn(), recordDependencyOnCurrentExtension(), recordDependencyOnOwner(), RelationGetDescr, RowExclusiveLock, SearchSysCacheExists3, simple_heap_insert(), and values.

Referenced by DefineCollation().

{
    Relation    rel;
    TupleDesc   tupDesc;
    HeapTuple   tup;
    Datum       values[Natts_pg_collation];
    bool        nulls[Natts_pg_collation];
    NameData    name_name,
                name_collate,
                name_ctype;
    Oid         oid;
    ObjectAddress myself,
                referenced;

    AssertArg(collname);
    AssertArg(collnamespace);
    AssertArg(collowner);
    AssertArg(collcollate);
    AssertArg(collctype);

    /*
     * Make sure there is no existing collation of same name & encoding.
     *
     * This would be caught by the unique index anyway; we're just giving a
     * friendlier error message.  The unique index provides a backstop against
     * race conditions.
     */
    if (SearchSysCacheExists3(COLLNAMEENCNSP,
                              PointerGetDatum(collname),
                              Int32GetDatum(collencoding),
                              ObjectIdGetDatum(collnamespace)))
        ereport(ERROR,
                (errcode(ERRCODE_DUPLICATE_OBJECT),
                 errmsg("collation \"%s\" for encoding \"%s\" already exists",
                        collname, pg_encoding_to_char(collencoding))));

    /*
     * Also forbid matching an any-encoding entry.  This test of course is not
     * backed up by the unique index, but it's not a problem since we don't
     * support adding any-encoding entries after initdb.
     */
    if (SearchSysCacheExists3(COLLNAMEENCNSP,
                              PointerGetDatum(collname),
                              Int32GetDatum(-1),
                              ObjectIdGetDatum(collnamespace)))
        ereport(ERROR,
                (errcode(ERRCODE_DUPLICATE_OBJECT),
                 errmsg("collation \"%s\" already exists",
                        collname)));

    /* open pg_collation */
    rel = heap_open(CollationRelationId, RowExclusiveLock);
    tupDesc = RelationGetDescr(rel);

    /* form a tuple */
    memset(nulls, 0, sizeof(nulls));

    namestrcpy(&name_name, collname);
    values[Anum_pg_collation_collname - 1] = NameGetDatum(&name_name);
    values[Anum_pg_collation_collnamespace - 1] = ObjectIdGetDatum(collnamespace);
    values[Anum_pg_collation_collowner - 1] = ObjectIdGetDatum(collowner);
    values[Anum_pg_collation_collencoding - 1] = Int32GetDatum(collencoding);
    namestrcpy(&name_collate, collcollate);
    values[Anum_pg_collation_collcollate - 1] = NameGetDatum(&name_collate);
    namestrcpy(&name_ctype, collctype);
    values[Anum_pg_collation_collctype - 1] = NameGetDatum(&name_ctype);

    tup = heap_form_tuple(tupDesc, values, nulls);

    /* insert a new tuple */
    oid = simple_heap_insert(rel, tup);
    Assert(OidIsValid(oid));

    /* update the index if any */
    CatalogUpdateIndexes(rel, tup);

    /* set up dependencies for the new collation */
    myself.classId = CollationRelationId;
    myself.objectId = oid;
    myself.objectSubId = 0;

    /* create dependency on namespace */
    referenced.classId = NamespaceRelationId;
    referenced.objectId = collnamespace;
    referenced.objectSubId = 0;
    recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);

    /* create dependency on owner */
    recordDependencyOnOwner(CollationRelationId, HeapTupleGetOid(tup),
                            collowner);

    /* dependency on extension */
    recordDependencyOnCurrentExtension(&myself, false);

    /* Post creation hook for new collation */
    InvokeObjectPostCreateHook(CollationRelationId, oid, 0);

    heap_freetuple(tup);
    heap_close(rel, RowExclusiveLock);

    return oid;
}

void RemoveCollationById

(

Oid

collationOid

)

Definition at line 154 of file pg_collation.c.

References BTEqualStrategyNumber, CollationOidIndexId, CollationRelationId, elog, ERROR, heap_close, heap_open(), HeapTupleIsValid, ObjectIdAttributeNumber, ObjectIdGetDatum, RowExclusiveLock, ScanKeyInit(), simple_heap_delete(), SnapshotNow, systable_beginscan(), systable_endscan(), systable_getnext(), and HeapTupleData::t_self.

Referenced by doDeletion().

{
    Relation    rel;
    ScanKeyData scanKeyData;
    SysScanDesc scandesc;
    HeapTuple   tuple;

    rel = heap_open(CollationRelationId, RowExclusiveLock);

    ScanKeyInit(&scanKeyData,
                ObjectIdAttributeNumber,
                BTEqualStrategyNumber, F_OIDEQ,
                ObjectIdGetDatum(collationOid));

    scandesc = systable_beginscan(rel, CollationOidIndexId, true,
                                  SnapshotNow, 1, &scanKeyData);

    tuple = systable_getnext(scandesc);

    if (HeapTupleIsValid(tuple))
        simple_heap_delete(rel, &tuple->t_self);
    else
        elog(ERROR, "could not find tuple for collation %u", collationOid);

    systable_endscan(scandesc);

    heap_close(rel, RowExclusiveLock);
}