@ -24,8 +24,10 @@
# include "catalog/pg_statistic_ext_data.h"
# include "miscadmin.h"
# include "nodes/makefuncs.h"
# include "statistics/extended_stats_internal.h"
# include "statistics/stat_utils.h"
# include "utils/acl.h"
# include "utils/array.h"
# include "utils/builtins.h"
# include "utils/fmgroids.h"
# include "utils/lsyscache.h"
@ -42,6 +44,7 @@ enum extended_stats_argnum
STATSCHEMA_ARG ,
STATNAME_ARG ,
INHERITED_ARG ,
NDISTINCT_ARG ,
NUM_EXTENDED_STATS_ARGS ,
} ;
@ -56,13 +59,33 @@ static struct StatsArgInfo extarginfo[] =
[ STATSCHEMA_ARG ] = { " statistics_schemaname " , TEXTOID } ,
[ STATNAME_ARG ] = { " statistics_name " , TEXTOID } ,
[ INHERITED_ARG ] = { " inherited " , BOOLOID } ,
[ NDISTINCT_ARG ] = { " n_distinct " , PG_NDISTINCTOID } ,
[ NUM_EXTENDED_STATS_ARGS ] = { 0 } ,
} ;
static bool extended_statistics_update ( FunctionCallInfo fcinfo ) ;
static HeapTuple get_pg_statistic_ext ( Relation pg_stext , Oid nspoid ,
const char * stxname ) ;
static bool delete_pg_statistic_ext_data ( Oid stxoid , bool inherited ) ;
/*
* Track the extended statistics kinds expected for a pg_statistic_ext
* tuple .
*/
typedef struct
{
bool ndistinct ;
bool dependencies ;
bool mcv ;
bool expressions ;
} StakindFlags ;
static void expand_stxkind ( HeapTuple tup , StakindFlags * enabled ) ;
static void upsert_pg_statistic_ext_data ( const Datum * values ,
const bool * nulls ,
const bool * replaces ) ;
/*
* Fetch a pg_statistic_ext row by name and namespace OID .
*/
@ -109,6 +132,278 @@ get_pg_statistic_ext(Relation pg_stext, Oid nspoid, const char *stxname)
return SearchSysCacheCopy1 ( STATEXTOID , ObjectIdGetDatum ( stxoid ) ) ;
}
/*
* Decode the stxkind column so that we know which stats types to expect ,
* returning a StakindFlags set depending on the stats kinds expected by
* a pg_statistic_ext tuple .
*/
static void
expand_stxkind ( HeapTuple tup , StakindFlags * enabled )
{
Datum datum ;
ArrayType * arr ;
char * kinds ;
datum = SysCacheGetAttrNotNull ( STATEXTOID ,
tup ,
Anum_pg_statistic_ext_stxkind ) ;
arr = DatumGetArrayTypeP ( datum ) ;
if ( ARR_NDIM ( arr ) ! = 1 | | ARR_HASNULL ( arr ) | | ARR_ELEMTYPE ( arr ) ! = CHAROID )
elog ( ERROR , " stxkind is not a one-dimension char array " ) ;
kinds = ( char * ) ARR_DATA_PTR ( arr ) ;
for ( int i = 0 ; i < ARR_DIMS ( arr ) [ 0 ] ; i + + )
{
switch ( kinds [ i ] )
{
case STATS_EXT_NDISTINCT :
enabled - > ndistinct = true ;
break ;
case STATS_EXT_DEPENDENCIES :
enabled - > dependencies = true ;
break ;
case STATS_EXT_MCV :
enabled - > mcv = true ;
break ;
case STATS_EXT_EXPRESSIONS :
enabled - > expressions = true ;
break ;
default :
elog ( ERROR , " incorrect stxkind %c found " , kinds [ i ] ) ;
break ;
}
}
}
/*
* Perform the actual storage of a pg_statistic_ext_data tuple .
*/
static void
upsert_pg_statistic_ext_data ( const Datum * values , const bool * nulls ,
const bool * replaces )
{
Relation pg_stextdata ;
HeapTuple stxdtup ;
HeapTuple newtup ;
pg_stextdata = table_open ( StatisticExtDataRelationId , RowExclusiveLock ) ;
stxdtup = SearchSysCache2 ( STATEXTDATASTXOID ,
values [ Anum_pg_statistic_ext_data_stxoid - 1 ] ,
values [ Anum_pg_statistic_ext_data_stxdinherit - 1 ] ) ;
if ( HeapTupleIsValid ( stxdtup ) )
{
newtup = heap_modify_tuple ( stxdtup ,
RelationGetDescr ( pg_stextdata ) ,
values ,
nulls ,
replaces ) ;
CatalogTupleUpdate ( pg_stextdata , & newtup - > t_self , newtup ) ;
ReleaseSysCache ( stxdtup ) ;
}
else
{
newtup = heap_form_tuple ( RelationGetDescr ( pg_stextdata ) , values , nulls ) ;
CatalogTupleInsert ( pg_stextdata , newtup ) ;
}
heap_freetuple ( newtup ) ;
CommandCounterIncrement ( ) ;
table_close ( pg_stextdata , RowExclusiveLock ) ;
}
/*
* Insert or update an extended statistics object .
*
* Major errors , such as the table not existing or permission errors , are
* reported as ERRORs . There are a couple of paths that generate a WARNING ,
* like when the statistics object or its schema do not exist , a conversion
* failure on one statistic kind , or when other statistic kinds may still
* be updated .
*/
static bool
extended_statistics_update ( FunctionCallInfo fcinfo )
{
char * relnspname ;
char * relname ;
Oid nspoid ;
char * nspname ;
char * stxname ;
bool inherited ;
Relation pg_stext = NULL ;
HeapTuple tup = NULL ;
StakindFlags enabled = { false , false , false , false } ;
StakindFlags has = { false , false , false , false } ;
Form_pg_statistic_ext stxform ;
Datum values [ Natts_pg_statistic_ext_data ] = { 0 } ;
bool nulls [ Natts_pg_statistic_ext_data ] ;
bool replaces [ Natts_pg_statistic_ext_data ] = { 0 } ;
bool success = true ;
int numexprs = 0 ;
/* arrays of type info, if we need them */
Oid relid ;
Oid locked_table = InvalidOid ;
/*
* Fill out the StakindFlags " has " structure based on which parameters
* were provided to the function .
*/
has . ndistinct = ! PG_ARGISNULL ( NDISTINCT_ARG ) ;
if ( RecoveryInProgress ( ) )
{
ereport ( WARNING ,
errcode ( ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE ) ,
errmsg ( " recovery is in progress " ) ,
errhint ( " Statistics cannot be modified during recovery. " ) ) ;
return false ;
}
/* relation arguments */
stats_check_required_arg ( fcinfo , extarginfo , RELSCHEMA_ARG ) ;
relnspname = TextDatumGetCString ( PG_GETARG_DATUM ( RELSCHEMA_ARG ) ) ;
stats_check_required_arg ( fcinfo , extarginfo , RELNAME_ARG ) ;
relname = TextDatumGetCString ( PG_GETARG_DATUM ( RELNAME_ARG ) ) ;
/* extended statistics arguments */
stats_check_required_arg ( fcinfo , extarginfo , STATSCHEMA_ARG ) ;
nspname = TextDatumGetCString ( PG_GETARG_DATUM ( STATSCHEMA_ARG ) ) ;
stats_check_required_arg ( fcinfo , extarginfo , STATNAME_ARG ) ;
stxname = TextDatumGetCString ( PG_GETARG_DATUM ( STATNAME_ARG ) ) ;
stats_check_required_arg ( fcinfo , extarginfo , INHERITED_ARG ) ;
inherited = PG_GETARG_BOOL ( INHERITED_ARG ) ;
/*
* First open the relation where we expect to find the statistics . This
* is similar to relation and attribute statistics , so as ACL checks are
* done before any locks are taken , even before any attempts related to
* the extended stats object .
*/
relid = RangeVarGetRelidExtended ( makeRangeVar ( relnspname , relname , - 1 ) ,
ShareUpdateExclusiveLock , 0 ,
RangeVarCallbackForStats , & locked_table ) ;
nspoid = get_namespace_oid ( nspname , true ) ;
if ( nspoid = = InvalidOid )
{
ereport ( WARNING ,
errcode ( ERRCODE_UNDEFINED_OBJECT ) ,
errmsg ( " could not find schema \" %s \" " , nspname ) ) ;
success = false ;
goto cleanup ;
}
pg_stext = table_open ( StatisticExtRelationId , RowExclusiveLock ) ;
tup = get_pg_statistic_ext ( pg_stext , nspoid , stxname ) ;
if ( ! HeapTupleIsValid ( tup ) )
{
ereport ( WARNING ,
errcode ( ERRCODE_UNDEFINED_OBJECT ) ,
errmsg ( " could not find extended statistics object \" %s \" . \" %s \" " ,
quote_identifier ( nspname ) ,
quote_identifier ( stxname ) ) ) ;
success = false ;
goto cleanup ;
}
stxform = ( Form_pg_statistic_ext ) GETSTRUCT ( tup ) ;
/*
* The relation tracked by the stats object has to match with the relation
* we have already locked .
*/
if ( stxform - > stxrelid ! = relid )
{
ereport ( WARNING ,
errcode ( ERRCODE_INVALID_PARAMETER_VALUE ) ,
errmsg ( " could not restore extended statistics object \" %s \" . \" %s \" : incorrect relation \" %s \" . \" %s \" specified " ,
quote_identifier ( nspname ) ,
quote_identifier ( stxname ) ,
quote_identifier ( relnspname ) ,
quote_identifier ( relname ) ) ) ;
success = false ;
goto cleanup ;
}
/* Find out what extended statistics kinds we should expect. */
expand_stxkind ( tup , & enabled ) ;
/*
* If the object cannot support ndistinct , we should not have data for it .
*/
if ( has . ndistinct & & ! enabled . ndistinct )
{
ereport ( WARNING ,
errcode ( ERRCODE_INVALID_PARAMETER_VALUE ) ,
errmsg ( " cannot not specify parameter \" %s \" " ,
extarginfo [ NDISTINCT_ARG ] . argname ) ,
errhint ( " Extended statistics object \" %s \" . \" %s \" does not support statistics of this type. " ,
quote_identifier ( nspname ) ,
quote_identifier ( stxname ) ) ) ;
has . ndistinct = false ;
success = false ;
}
/*
* Populate the pg_statistic_ext_data result tuple .
*/
/* Primary Key: cannot be NULL or replaced. */
values [ Anum_pg_statistic_ext_data_stxoid - 1 ] = ObjectIdGetDatum ( stxform - > oid ) ;
values [ Anum_pg_statistic_ext_data_stxdinherit - 1 ] = BoolGetDatum ( inherited ) ;
/* All unspecified parameters will be left unmodified */
nulls [ Anum_pg_statistic_ext_data_stxdndistinct - 1 ] = true ;
nulls [ Anum_pg_statistic_ext_data_stxddependencies - 1 ] = true ;
nulls [ Anum_pg_statistic_ext_data_stxdmcv - 1 ] = true ;
nulls [ Anum_pg_statistic_ext_data_stxdexpr - 1 ] = true ;
/*
* For each stats kind , deserialize the data at hand and perform a round
* of validation . The resulting tuple is filled with a set of updated
* values .
*/
if ( has . ndistinct )
{
Datum ndistinct_datum = PG_GETARG_DATUM ( NDISTINCT_ARG ) ;
bytea * data = DatumGetByteaPP ( ndistinct_datum ) ;
MVNDistinct * ndistinct = statext_ndistinct_deserialize ( data ) ;
if ( statext_ndistinct_validate ( ndistinct , & stxform - > stxkeys ,
numexprs , WARNING ) )
{
values [ Anum_pg_statistic_ext_data_stxdndistinct - 1 ] = ndistinct_datum ;
nulls [ Anum_pg_statistic_ext_data_stxdndistinct - 1 ] = false ;
replaces [ Anum_pg_statistic_ext_data_stxdndistinct - 1 ] = true ;
}
else
success = false ;
statext_ndistinct_free ( ndistinct ) ;
}
upsert_pg_statistic_ext_data ( values , nulls , replaces ) ;
cleanup :
if ( HeapTupleIsValid ( tup ) )
heap_freetuple ( tup ) ;
if ( pg_stext ! = NULL )
table_close ( pg_stext , RowExclusiveLock ) ;
return success ;
}
/*
* Remove an existing pg_statistic_ext_data row for a given pg_statistic_ext
* row and " inherited " pair .
@ -139,6 +434,31 @@ delete_pg_statistic_ext_data(Oid stxoid, bool inherited)
return result ;
}
/*
* Restore ( insert or replace ) statistics for the given statistics object .
*
* This function accepts variadic arguments in key - value pairs , which are
* given to stats_fill_fcinfo_from_arg_pairs to be mapped into positional
* arguments .
*/
Datum
pg_restore_extended_stats ( PG_FUNCTION_ARGS )
{
LOCAL_FCINFO ( positional_fcinfo , NUM_EXTENDED_STATS_ARGS ) ;
bool result = true ;
InitFunctionCallInfoData ( * positional_fcinfo , NULL , NUM_EXTENDED_STATS_ARGS ,
InvalidOid , NULL , NULL ) ;
if ( ! stats_fill_fcinfo_from_arg_pairs ( fcinfo , positional_fcinfo , extarginfo ) )
result = false ;
if ( ! extended_statistics_update ( positional_fcinfo ) )
result = false ;
PG_RETURN_BOOL ( result ) ;
}
/*
* Delete statistics for the given statistics object .
*/
Michael Paquier
1 week ago