stat_utils.c

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/*-------------------------------------------------------------------------
 * stat_utils.c
 *
 *    PostgreSQL statistics manipulation utilities.
 *
 * Code supporting the direct manipulation of statistics.
 *
 * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * IDENTIFICATION
 *       src/backend/statistics/stat_utils.c
 *
 *-------------------------------------------------------------------------
 */
 
#include "postgres.h"
 
#include "access/relation.h"
#include "catalog/pg_database.h"
#include "miscadmin.h"
#include "statistics/stat_utils.h"
#include "utils/acl.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/rel.h"
 
/*
 * Ensure that a given argument is not null.
 */
void
stats_check_required_arg(FunctionCallInfo fcinfo,
                         struct StatsArgInfo *arginfo,
                         int argnum)
{
    if (PG_ARGISNULL(argnum))
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("\"%s\" cannot be NULL",
                        arginfo[argnum].argname)));
}
 
/*
 * Check that argument is either NULL or a one dimensional array with no
 * NULLs.
 *
 * If a problem is found, emit at elevel, and return false. Otherwise return
 * true.
 */
bool
stats_check_arg_array(FunctionCallInfo fcinfo,
                      struct StatsArgInfo *arginfo,
                      int argnum, int elevel)
{
    ArrayType  *arr;
 
    if (PG_ARGISNULL(argnum))
        return true;
 
    arr = DatumGetArrayTypeP(PG_GETARG_DATUM(argnum));
 
    if (ARR_NDIM(arr) != 1)
    {
        ereport(elevel,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("\"%s\" cannot be a multidimensional array",
                        arginfo[argnum].argname)));
        return false;
    }
 
    if (array_contains_nulls(arr))
    {
        ereport(elevel,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("\"%s\" array cannot contain NULL values",
                        arginfo[argnum].argname)));
        return false;
    }
 
    return true;
}
 
/*
 * Enforce parameter pairs that must be specified together (or not at all) for
 * a particular stakind, such as most_common_vals and most_common_freqs for
 * STATISTIC_KIND_MCV.
 *
 * If a problem is found, emit at elevel, and return false. Otherwise return
 * true.
 */
bool
stats_check_arg_pair(FunctionCallInfo fcinfo,
                     struct StatsArgInfo *arginfo,
                     int argnum1, int argnum2, int elevel)
{
    if (PG_ARGISNULL(argnum1) && PG_ARGISNULL(argnum2))
        return true;
 
    if (PG_ARGISNULL(argnum1) || PG_ARGISNULL(argnum2))
    {
        int         nullarg = PG_ARGISNULL(argnum1) ? argnum1 : argnum2;
        int         otherarg = PG_ARGISNULL(argnum1) ? argnum2 : argnum1;
 
        ereport(elevel,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("\"%s\" must be specified when \"%s\" is specified",
                        arginfo[nullarg].argname,
                        arginfo[otherarg].argname)));
 
        return false;
    }
 
    return true;
}
 
/*
 * Lock relation in ShareUpdateExclusive mode, check privileges, and close the
 * relation (but retain the lock).
 *
 * A role has privileges to set statistics on the relation if any of the
 * following are true:
 *   - the role owns the current database and the relation is not shared
 *   - the role has the MAINTAIN privilege on the relation
 */
void
stats_lock_check_privileges(Oid reloid)
{
    Relation    rel = relation_open(reloid, ShareUpdateExclusiveLock);
    const char  relkind = rel->rd_rel->relkind;
 
    /* All of the types that can be used with ANALYZE, plus indexes */
    switch (relkind)
    {
        case RELKIND_RELATION:
        case RELKIND_INDEX:
        case RELKIND_MATVIEW:
        case RELKIND_FOREIGN_TABLE:
        case RELKIND_PARTITIONED_TABLE:
        case RELKIND_PARTITIONED_INDEX:
            break;
        default:
            ereport(ERROR,
                    (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                     errmsg("cannot modify statistics for relation \"%s\"",
                            RelationGetRelationName(rel)),
                     errdetail_relkind_not_supported(rel->rd_rel->relkind)));
    }
 
    if (rel->rd_rel->relisshared)
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("cannot modify statistics for shared relation")));
 
    if (!object_ownercheck(DatabaseRelationId, MyDatabaseId, GetUserId()))
    {
        AclResult   aclresult = pg_class_aclcheck(RelationGetRelid(rel),
                                                  GetUserId(),
                                                  ACL_MAINTAIN);
 
        if (aclresult != ACLCHECK_OK)
            aclcheck_error(aclresult,
                           get_relkind_objtype(rel->rd_rel->relkind),
                           NameStr(rel->rd_rel->relname));
    }
 
    relation_close(rel, NoLock);
}