Each metadata field can be of different data type.
The following types of record fields are used in metadata. If you need to see data types used in CTL, see Data Types in CTL2.
Table 32.1. Data Types in Metadata
| Data type | Size [1] | Range or values | Default value |
|---|---|---|---|
| boolean | Represents 1 bit. Its size is not precisely defined. | true | false |
1 | 0 | false | 0 |
| byte | Depends on the actual data length. | from -128 to 127 | null |
| cbyte | Depends on the actual data length and success of compression. | from -128 to 127 | null |
| date | 64 bits [2] | Starts January 1, 1970, 00:00:00 GMT and is incremented by 1 ms. | 1970-01-01, 00:00:00 GMT |
| decimal | Depends on Length and
Scale. (The former is the maximum number of all
digits, the latter is the maximum number of digits after the
decimal dot. Default values are 12 and 2, respectively.)
[3]
[4]
| decimal(6,2) (They can have values from
-9999.99 to 9999.99, length and scale can only be defined in CTL1) | 0.00 |
| integer | 32 bits [3] | From Integer.MIN_VALUE to
Integer.MAX_VALUE (according to the Java
integer data type): From -231 to
231-1.
Integer.MIN_VALUE is interpreted as
null. | 0 |
| long | 64 bits [3] | From Long.MIN_VALUE to
Long.MAX_VALUE (according to the Java long
data type): From -263 to
263-1.
Long.MIN_VALUE is interpreted as
null. | 0 |
| number | 64 bits [3] | Negative values are from
-(2-2-52).21023
to -2-1074, another value is 0, and
positive values are from 2-1074 to
(2-2-52).21023.
Three special values: NaN,
-Infinity, and Infinity
are defined. | 0.0 |
| string | Depends on the actual data length. Each character is stored in 16 bits. | Obviously you cannot have infinite strings. Instead
of limiting how many characters each string can consist of (theoretically up to 64K),
think about memory requirements. A string takes
(number of characters) * 2 bytes of memory. At the same time,
no record can take more than MAX_RECORD_SIZE
of bytes, see Chapter 18, Engine Configuration.
| null
[5]
|
[1] This column may look like an implementation detail but it is not so true.
Size lets you estimate how much memory your records are going
to need. To do that, take a look at how many fields your record has, which data
types they are and then compare the result to the [2] Any date can be parsed and formatted using date and time format pattern. See Date and Time Format. Parsing and formatting can also be influenced by locale. See Locale. [3] Any numeric data type can be parsed and formatted using numeric format pattern. See Numeric Format. Parsing and formatting may also be influenced by locale. See Locale. [4] The default [5] By default, if a field which is of the string
data type of any metadata is an empty string, such field value
is converted to | |||
For other information about these data types and other data types used in Clover transformation language (CTL) see Data Types in CTL2.