pgstat_kind.c

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/*-------------------------------------------------------------------------
 *
 * pgstat_kind.c
 *    Functions related to statistics kinds.
 *
 * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    src/backend/utils/activity/pgstat_kind.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"
 
#include "fmgr.h"
#include "funcapi.h"
#include "utils/builtins.h"
#include "utils/fmgrprotos.h"
#include "utils/pgstat_internal.h"
#include "utils/pgstat_kind.h"
#include "utils/tuplestore.h"
 
 
/*
 * pg_stat_get_kind_info
 *
 * Get information about the statistics kinds registered into the system.
 */
Datum
pg_stat_get_kind_info(PG_FUNCTION_ARGS)
{
#define PG_STAT_KIND_INFO_COLS  7
    ReturnSetInfo *rsinfo;
 
    InitMaterializedSRF(fcinfo, 0);
    rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
 
    for (int kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
    {
        Datum       values[PG_STAT_KIND_INFO_COLS] = {0};
        bool        nulls[PG_STAT_KIND_INFO_COLS] = {0};
        const PgStat_KindInfo *info;
 
        info = pgstat_get_kind_info(kind);
        if (info == NULL)
            continue;
 
        values[0] = Int32GetDatum(kind);
        values[1] = CStringGetTextDatum(info->name);
 
        values[2] = BoolGetDatum(pgstat_is_kind_builtin(kind));
        values[3] = BoolGetDatum(info->fixed_amount);
        values[4] = BoolGetDatum(info->accessed_across_databases);
        values[5] = BoolGetDatum(info->write_to_file);
 
        /*
         * When track_entry_count is disabled, use NULL.  Fixed-sized stats
         * kinds report NULL here.
         */
        if (info->track_entry_count)
            values[6] = Int64GetDatum(pgstat_get_entry_count(kind));
        else
            nulls[6] = true;
 
        tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
    }
 
    return (Datum) 0;
#undef PG_STAT_KIND_INFO_COLS
}