pg_aggregate.h

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/*-------------------------------------------------------------------------
 *
 * pg_aggregate.h
 *    definition of the "aggregate" system catalog (pg_aggregate)
 *
 *
 * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/catalog/pg_aggregate.h
 *
 * NOTES
 *    The Catalog.pm module reads this file and derives schema
 *    information.
 *
 *-------------------------------------------------------------------------
 */
#ifndef PG_AGGREGATE_H
#define PG_AGGREGATE_H

#include "catalog/genbki.h"
#include "catalog/pg_aggregate_d.h"

#include "catalog/objectaddress.h"
#include "nodes/pg_list.h"

/* ----------------------------------------------------------------
 *      pg_aggregate definition.
 *      cpp turns this into typedef struct FormData_pg_aggregate
 * ----------------------------------------------------------------
 */
CATALOG(pg_aggregate,2600,AggregateRelationId)
{
    /* pg_proc OID of the aggregate itself */
    regproc     aggfnoid BKI_LOOKUP(pg_proc);

    /* aggregate kind, see AGGKIND_ categories below */
    char        aggkind BKI_DEFAULT(n);

    /* number of arguments that are "direct" arguments */
    int16       aggnumdirectargs BKI_DEFAULT(0);

    /* transition function */
    regproc     aggtransfn BKI_LOOKUP(pg_proc);

    /* final function (0 if none) */
    regproc     aggfinalfn BKI_DEFAULT(-) BKI_LOOKUP(pg_proc);

    /* combine function (0 if none) */
    regproc     aggcombinefn BKI_DEFAULT(-) BKI_LOOKUP(pg_proc);

    /* function to convert transtype to bytea (0 if none) */
    regproc     aggserialfn BKI_DEFAULT(-) BKI_LOOKUP(pg_proc);

    /* function to convert bytea to transtype (0 if none) */
    regproc     aggdeserialfn BKI_DEFAULT(-) BKI_LOOKUP(pg_proc);

    /* forward function for moving-aggregate mode (0 if none) */
    regproc     aggmtransfn BKI_DEFAULT(-) BKI_LOOKUP(pg_proc);

    /* inverse function for moving-aggregate mode (0 if none) */
    regproc     aggminvtransfn BKI_DEFAULT(-) BKI_LOOKUP(pg_proc);

    /* final function for moving-aggregate mode (0 if none) */
    regproc     aggmfinalfn BKI_DEFAULT(-) BKI_LOOKUP(pg_proc);

    /* true to pass extra dummy arguments to aggfinalfn */
    bool        aggfinalextra BKI_DEFAULT(f);

    /* true to pass extra dummy arguments to aggmfinalfn */
    bool        aggmfinalextra BKI_DEFAULT(f);

    /* tells whether aggfinalfn modifies transition state */
    char        aggfinalmodify BKI_DEFAULT(r);

    /* tells whether aggmfinalfn modifies transition state */
    char        aggmfinalmodify BKI_DEFAULT(r);

    /* associated sort operator (0 if none) */
    Oid         aggsortop BKI_DEFAULT(0) BKI_LOOKUP(pg_operator);

    /* type of aggregate's transition (state) data */
    Oid         aggtranstype BKI_LOOKUP(pg_type);

    /* estimated size of state data (0 for default estimate) */
    int32       aggtransspace BKI_DEFAULT(0);

    /* type of moving-aggregate state data (0 if none) */
    Oid         aggmtranstype BKI_DEFAULT(0) BKI_LOOKUP(pg_type);

    /* estimated size of moving-agg state (0 for default est) */
    int32       aggmtransspace BKI_DEFAULT(0);

#ifdef CATALOG_VARLEN           /* variable-length fields start here */

    /* initial value for transition state (can be NULL) */
    text        agginitval BKI_DEFAULT(_null_);

    /* initial value for moving-agg state (can be NULL) */
    text        aggminitval BKI_DEFAULT(_null_);
#endif
} FormData_pg_aggregate;

/* ----------------
 *      Form_pg_aggregate corresponds to a pointer to a tuple with
 *      the format of pg_aggregate relation.
 * ----------------
 */
typedef FormData_pg_aggregate *Form_pg_aggregate;

#ifdef EXPOSE_TO_CLIENT_CODE

/*
 * Symbolic values for aggkind column.  We distinguish normal aggregates
 * from ordered-set aggregates (which have two sets of arguments, namely
 * direct and aggregated arguments) and from hypothetical-set aggregates
 * (which are a subclass of ordered-set aggregates in which the last
 * direct arguments have to match up in number and datatypes with the
 * aggregated arguments).
 */
#define AGGKIND_NORMAL          'n'
#define AGGKIND_ORDERED_SET     'o'
#define AGGKIND_HYPOTHETICAL    'h'

/* Use this macro to test for "ordered-set agg including hypothetical case" */
#define AGGKIND_IS_ORDERED_SET(kind)  ((kind) != AGGKIND_NORMAL)

/*
 * Symbolic values for aggfinalmodify and aggmfinalmodify columns.
 * Preferably, finalfns do not modify the transition state value at all,
 * but in some cases that would cost too much performance.  We distinguish
 * "pure read only" and "trashes it arbitrarily" cases, as well as the
 * intermediate case where multiple finalfn calls are allowed but the
 * transfn cannot be applied anymore after the first finalfn call.
 */
#define AGGMODIFY_READ_ONLY         'r'
#define AGGMODIFY_SHAREABLE         's'
#define AGGMODIFY_READ_WRITE        'w'

#endif                          /* EXPOSE_TO_CLIENT_CODE */


extern ObjectAddress AggregateCreate(const char *aggName,
                                     Oid aggNamespace,
                                     bool replace,
                                     char aggKind,
                                     int numArgs,
                                     int numDirectArgs,
                                     oidvector *parameterTypes,
                                     Datum allParameterTypes,
                                     Datum parameterModes,
                                     Datum parameterNames,
                                     List *parameterDefaults,
                                     Oid variadicArgType,
                                     List *aggtransfnName,
                                     List *aggfinalfnName,
                                     List *aggcombinefnName,
                                     List *aggserialfnName,
                                     List *aggdeserialfnName,
                                     List *aggmtransfnName,
                                     List *aggminvtransfnName,
                                     List *aggmfinalfnName,
                                     bool finalfnExtraArgs,
                                     bool mfinalfnExtraArgs,
                                     char finalfnModify,
                                     char mfinalfnModify,
                                     List *aggsortopName,
                                     Oid aggTransType,
                                     int32 aggTransSpace,
                                     Oid aggmTransType,
                                     int32 aggmTransSpace,
                                     const char *agginitval,
                                     const char *aggminitval,
                                     char proparallel);

#endif                          /* PG_AGGREGATE_H */