1/*-------------------------------------------------------------------------
4 * POSTGRES Datum (abstract data type) manipulation routines.
6 * These routines are driven by the 'typbyval' and 'typlen' information,
7 * which must previously have been obtained by the caller for the datatype
8 * of the Datum. (We do it this way because in most situations the caller
9 * can look up the info just once and use it for many per-datum operations.)
11 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
12 * Portions Copyright (c) 1994, Regents of the University of California
14 * src/include/utils/datum.h
16 *-------------------------------------------------------------------------
22 * datumGetSize - find the "real" length of a datum
27 * datumCopy - make a copy of a non-NULL datum.
29 * If the datatype is pass-by-reference, memory is obtained with palloc().
34 * datumTransfer - transfer a non-NULL datum into the current memory context.
36 * Differs from datumCopy() in its handling of read-write expanded objects.
42 * return true if two datums of the same type are equal, false otherwise.
44 * XXX : See comments in the code for restrictions!
47 bool typByVal,
int typLen);
52 * Compares two datums for identical contents, based on byte images. Return
53 * true if the two datums are equal, false otherwise.
56 bool typByVal,
int typLen);
61 * Generates hash value for 'value' based on its bits rather than logical
67 * Serialize and restore datums so that we can transfer them to parallel
73 int typLen,
char **start_address);
Datum datumCopy(Datum value, bool typByVal, int typLen)
Datum datumTransfer(Datum value, bool typByVal, int typLen)
Size datumGetSize(Datum value, bool typByVal, int typLen)
uint32 datum_image_hash(Datum value, bool typByVal, int typLen)
Datum datumRestore(char **start_address, bool *isnull)
void datumSerialize(Datum value, bool isnull, bool typByVal, int typLen, char **start_address)
Size datumEstimateSpace(Datum value, bool isnull, bool typByVal, int typLen)
bool datum_image_eq(Datum value1, Datum value2, bool typByVal, int typLen)
bool datumIsEqual(Datum value1, Datum value2, bool typByVal, int typLen)