stat_utils.h File Reference

#include "access/attnum.h"
#include "fmgr.h"

Include dependency graph for stat_utils.h:

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Data Structures
struct	StatsArgInfo

Typedefs
typedef struct RangeVar	RangeVar

Functions
void	stats_check_required_arg (FunctionCallInfo fcinfo, struct StatsArgInfo *arginfo, int argnum)
bool	stats_check_arg_array (FunctionCallInfo fcinfo, struct StatsArgInfo *arginfo, int argnum)
bool	stats_check_arg_pair (FunctionCallInfo fcinfo, struct StatsArgInfo *arginfo, int argnum1, int argnum2)
void	RangeVarCallbackForStats (const RangeVar *relation, Oid relId, Oid oldRelId, void *arg)
bool	stats_fill_fcinfo_from_arg_pairs (FunctionCallInfo pairs_fcinfo, FunctionCallInfo positional_fcinfo, struct StatsArgInfo *arginfo)
void	statatt_get_type (Oid reloid, AttrNumber attnum, Oid *atttypid, int32 *atttypmod, char *atttyptype, Oid *atttypcoll, Oid *eq_opr, Oid *lt_opr)
void	statatt_init_empty_tuple (Oid reloid, int16 attnum, bool inherited, Datum *values, bool *nulls, bool *replaces)
void	statatt_set_slot (Datum *values, bool *nulls, bool *replaces, int16 stakind, Oid staop, Oid stacoll, Datum stanumbers, bool stanumbers_isnull, Datum stavalues, bool stavalues_isnull)
Datum	statatt_build_stavalues (const char *staname, FmgrInfo *array_in, Datum d, Oid typid, int32 typmod, bool *ok)
bool	statatt_get_elem_type (Oid atttypid, char atttyptype, Oid *elemtypid, Oid *elem_eq_opr)
bool	statatt_check_bounds_histogram (Datum arrayval)

Typedef Documentation

RangeVar

typedef struct RangeVar RangeVar

Definition at line 20 of file stat_utils.h.

Function Documentation

RangeVarCallbackForStats()

void RangeVarCallbackForStats ( const RangeVar *  relation, Oid  relId, Oid  oldRelId, void *  arg  )

extern

Definition at line 143 of file stat_utils.c.

{
    Oid        *locked_oid = (Oid *) arg;
    Oid         table_oid = relId;
    HeapTuple   tuple;
    Form_pg_class form;
    char        relkind;
 
    /*
     * If we previously locked some other index's heap, and the name we're
     * looking up no longer refers to that relation, release the now-useless
     * lock.
     */
    if (relId != oldRelId && OidIsValid(*locked_oid))
    {
        UnlockRelationOid(*locked_oid, ShareUpdateExclusiveLock);
        *locked_oid = InvalidOid;
    }
 
    /* If the relation does not exist, there's nothing more to do. */
    if (!OidIsValid(relId))
        return;
 
    /* If the relation does exist, check whether it's an index. */
    relkind = get_rel_relkind(relId);
    if (relkind == RELKIND_INDEX ||
        relkind == RELKIND_PARTITIONED_INDEX)
        table_oid = IndexGetRelation(relId, false);
 
    /*
     * If retrying yields the same OID, there are a couple of extremely
     * unlikely scenarios we need to handle.
     */
    if (relId == oldRelId)
    {
        /*
         * If a previous lookup found an index, but the current lookup did
         * not, the index was dropped and the OID was reused for something
         * else between lookups.  In theory, we could simply drop our lock on
         * the index's parent table and proceed, but in the interest of
         * avoiding complexity, we just error.
         */
        if (table_oid == relId && OidIsValid(*locked_oid))
            ereport(ERROR,
                    (errcode(ERRCODE_UNDEFINED_OBJECT),
                     errmsg("index \"%s\" was concurrently dropped",
                            relation->relname)));
 
        /*
         * If the current lookup found an index but a previous lookup either
         * did not find an index or found one with a different parent
         * relation, the relation was dropped and the OID was reused for an
         * index between lookups.  RangeVarGetRelidExtended() will have
         * already locked the index at this point, so we can't just lock the
         * newly discovered parent table OID without risking deadlock.  As
         * above, we just error in this case.
         */
        if (table_oid != relId && table_oid != *locked_oid)
            ereport(ERROR,
                    (errcode(ERRCODE_UNDEFINED_OBJECT),
                     errmsg("index \"%s\" was concurrently created",
                            relation->relname)));
    }
 
    tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(table_oid));
    if (!HeapTupleIsValid(tuple))
        elog(ERROR, "cache lookup failed for OID %u", table_oid);
    form = (Form_pg_class) GETSTRUCT(tuple);
 
    /* the relkinds that can be used with ANALYZE */
    switch (form->relkind)
    {
        case RELKIND_RELATION:
        case RELKIND_MATVIEW:
        case RELKIND_FOREIGN_TABLE:
        case RELKIND_PARTITIONED_TABLE:
            break;
        default:
            ereport(ERROR,
                    (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                     errmsg("cannot modify statistics for relation \"%s\"",
                            NameStr(form->relname)),
                     errdetail_relkind_not_supported(form->relkind)));
    }
 
    if (form->relisshared)
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("cannot modify statistics for shared relation")));
 
    /* Check permissions */
    if (!object_ownercheck(DatabaseRelationId, MyDatabaseId, GetUserId()))
    {
        AclResult   aclresult = pg_class_aclcheck(table_oid,
                                                  GetUserId(),
                                                  ACL_MAINTAIN);
 
        if (aclresult != ACLCHECK_OK)
            aclcheck_error(aclresult,
                           get_relkind_objtype(form->relkind),
                           NameStr(form->relname));
    }
 
    ReleaseSysCache(tuple);
 
    /* Lock heap before index to avoid deadlock. */
    if (relId != oldRelId && table_oid != relId)
    {
        LockRelationOid(table_oid, ShareUpdateExclusiveLock);
        *locked_oid = table_oid;

References ACL_MAINTAIN, aclcheck_error(), ACLCHECK_OK, arg, elog, ereport, errcode(), errdetail_relkind_not_supported(), errmsg, ERROR, fb(), get_rel_relkind(), get_relkind_objtype(), GETSTRUCT(), GetUserId(), HeapTupleIsValid, IndexGetRelation(), InvalidOid, LockRelationOid(), MyDatabaseId, NameStr, object_ownercheck(), ObjectIdGetDatum(), OidIsValid, pg_class_aclcheck(), ReleaseSysCache(), RangeVar::relname, SearchSysCache1(), ShareUpdateExclusiveLock, and UnlockRelationOid().

Referenced by attribute_statistics_update(), extended_statistics_update(), pg_clear_attribute_stats(), pg_clear_extended_stats(), and relation_statistics_update().

statatt_build_stavalues()

Datum statatt_build_stavalues ( const char *  staname, FmgrInfo *  array_in, Datum  d, Oid  typid, int32  typmod, bool *  ok  )

extern

Definition at line 568 of file stat_utils.c.

{
    char       *s;
    Datum       result;
    ErrorSaveContext escontext = {T_ErrorSaveContext};
 
    escontext.details_wanted = true;
 
    s = TextDatumGetCString(d);
 
    if (!InputFunctionCallSafe(array_in, s, typid, typmod,
                               (Node *) &escontext, &result))
    {
        pfree(s);
        escontext.error_data->elevel = WARNING;
        ThrowErrorData(escontext.error_data);
        *ok = false;
        return (Datum) 0;
    }
 
    pfree(s);
 
    if (ARR_NDIM(DatumGetArrayTypeP(result)) != 1)
    {
        ereport(WARNING,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("\"%s\" must be a one-dimensional array", staname)));
        *ok = false;
        return (Datum) 0;
    }
 
    if (array_contains_nulls(DatumGetArrayTypeP(result)))
    {
        ereport(WARNING,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("\"%s\" array must not contain null values", staname)));
        *ok = false;
        return (Datum) 0;
    }
 
    *ok = true;
 

References ARR_NDIM, array_contains_nulls(), array_in(), DatumGetArrayTypeP, ErrorSaveContext::details_wanted, ErrorData::elevel, ereport, errcode(), errmsg, ErrorSaveContext::error_data, fb(), InputFunctionCallSafe(), pfree(), result, TextDatumGetCString, ThrowErrorData(), and WARNING.

Referenced by attribute_statistics_update_internal().

statatt_check_bounds_histogram()

bool statatt_check_bounds_histogram ( Datum  arrayval )

extern

Definition at line 753 of file stat_utils.c.

{
    ArrayType  *arr = DatumGetArrayTypeP(arrayval);
    Oid         rngtypid = ARR_ELEMTYPE(arr);
    TypeCacheEntry *typcache;
    int16       elmlen;
    bool        elmbyval;
    char        elmalign;
    Datum      *elems;
    bool       *nulls;
    int         nelems;
    RangeBound  prev_lower = {0};
    RangeBound  prev_upper = {0};
 
    typcache = lookup_type_cache(rngtypid, TYPECACHE_RANGE_INFO);
 
    /*
     * The element type should always be a range type here.  This is
     * defensive. If it isn't, the bounds histogram is never consulted by the
     * range estimator, and there is nothing to verify.
     */
    if (typcache->rngelemtype == NULL)
        return true;
 
    get_typlenbyvalalign(rngtypid, &elmlen, &elmbyval, &elmalign);
    deconstruct_array(arr, rngtypid, elmlen, elmbyval, elmalign,
                      &elems, &nulls, &nelems);
 
    for (int i = 0; i < nelems; i++)
    {
        RangeBound  lower,
                    upper;
        bool        empty;
 
        /*
         * NULL elements are already rejected by statatt_build_stavalues() and
         * array_in_safe().
         */
        range_deserialize(typcache, DatumGetRangeTypeP(elems[i]),
                          &lower, &upper, &empty);
 
        if (empty)
        {
            ereport(WARNING,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("\"%s\" must not contain empty ranges",
                            "range_bounds_histogram")));
            return false;
        }
 
        if (i > 0 &&
            (range_cmp_bounds(typcache, &lower, &prev_lower) < 0 ||
             range_cmp_bounds(typcache, &upper, &prev_upper) < 0))
        {
            ereport(WARNING,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("\"%s\" must have its lower and upper bounds sorted in ascending order",
                            "range_bounds_histogram")));
            return false;
        }
 
        prev_lower = lower;
        prev_upper = upper;
    }
 

References ARR_ELEMTYPE, DatumGetArrayTypeP, DatumGetRangeTypeP(), deconstruct_array(), ereport, errcode(), errmsg, fb(), get_typlenbyvalalign(), i, lookup_type_cache(), lower(), range_cmp_bounds(), range_deserialize(), TypeCacheEntry::rngelemtype, TYPECACHE_RANGE_INFO, upper(), and WARNING.

Referenced by attribute_statistics_update_internal(), and import_pg_statistic().

statatt_get_elem_type()

bool statatt_get_elem_type ( Oid  atttypid, char  atttyptype, Oid *  elemtypid, Oid *  elem_eq_opr  )

extern

Definition at line 524 of file stat_utils.c.

{
    TypeCacheEntry *elemtypcache;
 
    if (atttypid == TSVECTOROID)
    {
        /*
         * Special case: element type for tsvector is text. See
         * compute_tsvector_stats().
         */
        *elemtypid = TEXTOID;
    }
    else
    {
        /* find underlying element type through any domain */
        *elemtypid = get_base_element_type(atttypid);
    }
 
    if (!OidIsValid(*elemtypid))
        return false;
 
    /* finds the right operator even if elemtypid is a domain */
    elemtypcache = lookup_type_cache(*elemtypid, TYPECACHE_EQ_OPR);
    if (!OidIsValid(elemtypcache->eq_opr))
        return false;
 
    *elem_eq_opr = elemtypcache->eq_opr;
 

References fb(), get_base_element_type(), lookup_type_cache(), OidIsValid, and TYPECACHE_EQ_OPR.

Referenced by attribute_statistics_update_internal(), and import_pg_statistic().

statatt_get_type()

void statatt_get_type ( Oid  reloid, AttrNumber  attnum, Oid *  atttypid, int32 *  atttypmod, char *  atttyptype, Oid *  atttypcoll, Oid *  eq_opr, Oid *  lt_opr  )

extern

Definition at line 438 of file stat_utils.c.

{
    Relation    rel = relation_open(reloid, AccessShareLock);
    Form_pg_attribute attr;
    HeapTuple   atup;
    Node       *expr;
    TypeCacheEntry *typcache;
 
    atup = SearchSysCache2(ATTNUM, ObjectIdGetDatum(reloid),
                           Int16GetDatum(attnum));
 
    /* Attribute not found */
    if (!HeapTupleIsValid(atup))
        ereport(ERROR,
                (errcode(ERRCODE_UNDEFINED_COLUMN),
                 errmsg("column %d of relation \"%s\" does not exist",
                        attnum, RelationGetRelationName(rel))));
 
    attr = (Form_pg_attribute) GETSTRUCT(atup);
 
    if (attr->attisdropped)
        ereport(ERROR,
                (errcode(ERRCODE_UNDEFINED_COLUMN),
                 errmsg("column %d of relation \"%s\" does not exist",
                        attnum, RelationGetRelationName(rel))));
 
    expr = statatt_get_index_expr(rel, attr->attnum);
 
    /*
     * When analyzing an expression index, believe the expression tree's type
     * not the column datatype --- the latter might be the opckeytype storage
     * type of the opclass, which is not interesting for our purposes.  This
     * mimics the behavior of examine_attribute().
     */
    if (expr == NULL)
    {
        *atttypid = attr->atttypid;
        *atttypmod = attr->atttypmod;
        *atttypcoll = attr->attcollation;
    }
    else
    {
        *atttypid = exprType(expr);
        *atttypmod = exprTypmod(expr);
 
        if (OidIsValid(attr->attcollation))
            *atttypcoll = attr->attcollation;
        else
            *atttypcoll = exprCollation(expr);
    }
    ReleaseSysCache(atup);
 
    /*
     * If it's a multirange, step down to the range type, as is done by
     * multirange_typanalyze().
     */
    if (type_is_multirange(*atttypid))
        *atttypid = get_multirange_range(*atttypid);
 
    /* finds the right operators even if atttypid is a domain */
    typcache = lookup_type_cache(*atttypid, TYPECACHE_LT_OPR | TYPECACHE_EQ_OPR);
    *atttyptype = typcache->typtype;
    *eq_opr = typcache->eq_opr;
    *lt_opr = typcache->lt_opr;
 
    /*
     * Special case: collation for tsvector is DEFAULT_COLLATION_OID. See
     * compute_tsvector_stats().
     */
    if (*atttypid == TSVECTOROID)
        *atttypcoll = DEFAULT_COLLATION_OID;
 

References AccessShareLock, attnum, TypeCacheEntry::eq_opr, ereport, errcode(), errmsg, ERROR, exprCollation(), exprType(), exprTypmod(), fb(), get_multirange_range(), GETSTRUCT(), HeapTupleIsValid, Int16GetDatum(), lookup_type_cache(), TypeCacheEntry::lt_opr, NoLock, ObjectIdGetDatum(), OidIsValid, relation_close(), relation_open(), RelationGetRelationName, ReleaseSysCache(), SearchSysCache2(), statatt_get_index_expr(), type_is_multirange(), TYPECACHE_EQ_OPR, TYPECACHE_LT_OPR, and TypeCacheEntry::typtype.

Referenced by attribute_statistics_update_internal().

statatt_init_empty_tuple()

void statatt_init_empty_tuple ( Oid  reloid, int16  attnum, bool  inherited, Datum *  values, bool *  nulls, bool *  replaces  )

extern

Definition at line 712 of file stat_utils.c.

{
    memset(nulls, true, sizeof(bool) * Natts_pg_statistic);
    memset(replaces, true, sizeof(bool) * Natts_pg_statistic);
 
    /* This must initialize non-NULL attributes */
    values[Anum_pg_statistic_starelid - 1] = ObjectIdGetDatum(reloid);
    nulls[Anum_pg_statistic_starelid - 1] = false;
    values[Anum_pg_statistic_staattnum - 1] = Int16GetDatum(attnum);
    nulls[Anum_pg_statistic_staattnum - 1] = false;
    values[Anum_pg_statistic_stainherit - 1] = BoolGetDatum(inherited);
    nulls[Anum_pg_statistic_stainherit - 1] = false;
 
    values[Anum_pg_statistic_stanullfrac - 1] = DEFAULT_STATATT_NULL_FRAC;
    nulls[Anum_pg_statistic_stanullfrac - 1] = false;
    values[Anum_pg_statistic_stawidth - 1] = DEFAULT_STATATT_AVG_WIDTH;
    nulls[Anum_pg_statistic_stawidth - 1] = false;
    values[Anum_pg_statistic_stadistinct - 1] = DEFAULT_STATATT_N_DISTINCT;
    nulls[Anum_pg_statistic_stadistinct - 1] = false;
 
    /* initialize stakind, staop, and stacoll slots */
    for (int slotnum = 0; slotnum < STATISTIC_NUM_SLOTS; slotnum++)
    {
        values[Anum_pg_statistic_stakind1 + slotnum - 1] = (Datum) 0;
        nulls[Anum_pg_statistic_stakind1 + slotnum - 1] = false;
        values[Anum_pg_statistic_staop1 + slotnum - 1] = ObjectIdGetDatum(InvalidOid);
        nulls[Anum_pg_statistic_staop1 + slotnum - 1] = false;
        values[Anum_pg_statistic_stacoll1 + slotnum - 1] = ObjectIdGetDatum(InvalidOid);
        nulls[Anum_pg_statistic_stacoll1 + slotnum - 1] = false;

References attnum, BoolGetDatum(), DEFAULT_STATATT_AVG_WIDTH, DEFAULT_STATATT_N_DISTINCT, DEFAULT_STATATT_NULL_FRAC, fb(), Int16GetDatum(), InvalidOid, ObjectIdGetDatum(), STATISTIC_NUM_SLOTS, and values.

Referenced by attribute_statistics_update_internal(), and import_pg_statistic().

statatt_set_slot()

void statatt_set_slot ( Datum *  values, bool *  nulls, bool *  replaces, int16  stakind, Oid  staop, Oid  stacoll, Datum  stanumbers, bool  stanumbers_isnull, Datum  stavalues, bool  stavalues_isnull  )

extern

Definition at line 634 of file stat_utils.c.

{
    int         slotidx;
    int         first_empty = -1;
    AttrNumber  stakind_attnum;
    AttrNumber  staop_attnum;
    AttrNumber  stacoll_attnum;
 
    /* find existing slot with given stakind */
    for (slotidx = 0; slotidx < STATISTIC_NUM_SLOTS; slotidx++)
    {
        stakind_attnum = Anum_pg_statistic_stakind1 - 1 + slotidx;
 
        if (first_empty < 0 &&
            DatumGetInt16(values[stakind_attnum]) == 0)
            first_empty = slotidx;
        if (DatumGetInt16(values[stakind_attnum]) == stakind)
            break;
    }
 
    if (slotidx >= STATISTIC_NUM_SLOTS && first_empty >= 0)
        slotidx = first_empty;
 
    if (slotidx >= STATISTIC_NUM_SLOTS)
        ereport(ERROR,
                (errmsg("maximum number of statistics slots exceeded: %d",
                        slotidx + 1)));
 
    stakind_attnum = Anum_pg_statistic_stakind1 - 1 + slotidx;
    staop_attnum = Anum_pg_statistic_staop1 - 1 + slotidx;
    stacoll_attnum = Anum_pg_statistic_stacoll1 - 1 + slotidx;
 
    if (DatumGetInt16(values[stakind_attnum]) != stakind)
    {
        values[stakind_attnum] = Int16GetDatum(stakind);
        replaces[stakind_attnum] = true;
    }
    if (DatumGetObjectId(values[staop_attnum]) != staop)
    {
        values[staop_attnum] = ObjectIdGetDatum(staop);
        replaces[staop_attnum] = true;
    }
    if (DatumGetObjectId(values[stacoll_attnum]) != stacoll)
    {
        values[stacoll_attnum] = ObjectIdGetDatum(stacoll);
        replaces[stacoll_attnum] = true;
    }
    if (!stanumbers_isnull)
    {
        values[Anum_pg_statistic_stanumbers1 - 1 + slotidx] = stanumbers;
        nulls[Anum_pg_statistic_stanumbers1 - 1 + slotidx] = false;
        replaces[Anum_pg_statistic_stanumbers1 - 1 + slotidx] = true;
    }
    if (!stavalues_isnull)
    {
        values[Anum_pg_statistic_stavalues1 - 1 + slotidx] = stavalues;
        nulls[Anum_pg_statistic_stavalues1 - 1 + slotidx] = false;
        replaces[Anum_pg_statistic_stavalues1 - 1 + slotidx] = true;

References DatumGetInt16(), DatumGetObjectId(), ereport, errmsg, ERROR, fb(), Int16GetDatum(), ObjectIdGetDatum(), STATISTIC_NUM_SLOTS, and values.

Referenced by attribute_statistics_update_internal(), and import_pg_statistic().

stats_check_arg_array()

bool stats_check_arg_array ( FunctionCallInfo  fcinfo, struct StatsArgInfo *  arginfo, int  argnum  )

extern

Definition at line 71 of file stat_utils.c.

{
    ArrayType  *arr;
 
    if (PG_ARGISNULL(argnum))
        return true;
 
    arr = DatumGetArrayTypeP(PG_GETARG_DATUM(argnum));
 
    if (ARR_NDIM(arr) != 1)
    {
        ereport(WARNING,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("argument \"%s\" must not be a multidimensional array",
                        arginfo[argnum].argname)));
        return false;
    }
 
    if (array_contains_nulls(arr))
    {
        ereport(WARNING,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("argument \"%s\" array must not contain null values",
                        arginfo[argnum].argname)));
        return false;
    }
 

References ARR_NDIM, array_contains_nulls(), DatumGetArrayTypeP, ereport, errcode(), errmsg, fb(), PG_ARGISNULL, PG_GETARG_DATUM, and WARNING.

Referenced by attribute_statistics_update_internal().

stats_check_arg_pair()

bool stats_check_arg_pair ( FunctionCallInfo  fcinfo, struct StatsArgInfo *  arginfo, int  argnum1, int  argnum2  )

extern

Definition at line 112 of file stat_utils.c.

{
    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(WARNING,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("argument \"%s\" must be specified when argument \"%s\" is specified",
                        arginfo[nullarg].argname,
                        arginfo[otherarg].argname)));
 
        return false;
    }
 

References ereport, errcode(), errmsg, fb(), PG_ARGISNULL, and WARNING.

Referenced by attribute_statistics_update_internal().

stats_check_required_arg()

void stats_check_required_arg ( FunctionCallInfo  fcinfo, struct StatsArgInfo *  arginfo, int  argnum  )

extern

Definition at line 52 of file stat_utils.c.

{
    if (PG_ARGISNULL(argnum))
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("argument \"%s\" must not be null",

References ereport, errcode(), errmsg, ERROR, fb(), and PG_ARGISNULL.

Referenced by attribute_statistics_update(), extended_statistics_update(), pg_clear_attribute_stats(), pg_clear_extended_stats(), and relation_statistics_update().

stats_fill_fcinfo_from_arg_pairs()

bool stats_fill_fcinfo_from_arg_pairs ( FunctionCallInfo  pairs_fcinfo, FunctionCallInfo  positional_fcinfo, struct StatsArgInfo *  arginfo  )

extern

Definition at line 349 of file stat_utils.c.

{
    Datum      *args;
    bool       *argnulls;
    Oid        *types;
    int         nargs;
    bool        result = true;
 
    /* clear positional args */
    for (int i = 0; arginfo[i].argname != NULL; i++)
    {
        positional_fcinfo->args[i].value = (Datum) 0;
        positional_fcinfo->args[i].isnull = true;
    }
 
    nargs = extract_variadic_args(pairs_fcinfo, 0, true,
                                  &args, &types, &argnulls);
 
    if (nargs % 2 != 0)
        ereport(ERROR,
                errmsg("variadic arguments must be name/value pairs"),
                errhint("Provide an even number of variadic arguments that can be divided into pairs."));
 
    /*
     * For each argument name/value pair, find corresponding positional
     * argument for the argument name, and assign the argument value to
     * positional_fcinfo.
     */
    for (int i = 0; i < nargs; i += 2)
    {
        int         argnum;
        char       *argname;
 
        if (argnulls[i])
            ereport(ERROR,
                    (errmsg("name at variadic position %d is null", i + 1)));
 
        if (types[i] != TEXTOID)
            ereport(ERROR,
                    (errmsg("name at variadic position %d has type %s, expected type %s",
                            i + 1, format_type_be(types[i]),
                            format_type_be(TEXTOID))));
 
        if (argnulls[i + 1])
            continue;
 
        argname = TextDatumGetCString(args[i]);
 
        /*
         * The 'version' argument is a special case, not handled by arginfo
         * because it's not a valid positional argument.
         *
         * For now, 'version' is accepted but ignored. In the future it can be
         * used to interpret older statistics properly.
         */
        if (pg_strcasecmp(argname, "version") == 0)
            continue;
 
        argnum = get_arg_by_name(argname, arginfo);
 
        if (argnum < 0 || !stats_check_arg_type(argname, types[i + 1],
                                                arginfo[argnum].argtype))
        {
            result = false;
            continue;
        }
 
        positional_fcinfo->args[argnum].value = args[i + 1];
        positional_fcinfo->args[argnum].isnull = false;
    }
 

References ereport, errhint(), errmsg, ERROR, extract_variadic_args(), fb(), format_type_be(), get_arg_by_name(), i, pg_strcasecmp(), result, stats_check_arg_type(), TextDatumGetCString, and types.

Referenced by pg_restore_attribute_stats(), pg_restore_extended_stats(), and pg_restore_relation_stats().