@ -209,6 +209,9 @@ static int nbinaryUpgradeClassOids = 0;
static SequenceItem * sequences = NULL ;
static int nsequences = 0 ;
/* Maximum number of relations to fetch in a fetchAttributeStats() call. */
# define MAX_ATTR_STATS_RELS 64
/*
* The default number of rows per INSERT when
* - - inserts is specified without - - rows - per - insert
@ -10553,6 +10556,77 @@ appendNamedArgument(PQExpBuffer out, Archive *fout, const char *argname,
appendPQExpBuffer ( out , " ::%s " , argtype ) ;
}
/*
* fetchAttributeStats - -
*
* Fetch next batch of attribute statistics for dumpRelationStats_dumper ( ) .
*/
static PGresult *
fetchAttributeStats ( Archive * fout )
{
ArchiveHandle * AH = ( ArchiveHandle * ) fout ;
PQExpBuffer nspnames = createPQExpBuffer ( ) ;
PQExpBuffer relnames = createPQExpBuffer ( ) ;
int count = 0 ;
PGresult * res = NULL ;
static TocEntry * te ;
static bool restarted ;
/* If we're just starting, set our TOC pointer. */
if ( ! te )
te = AH - > toc - > next ;
/*
* We can ' t easily avoid a second TOC scan for the tar format because it
* writes restore . sql separately , which means we must execute the queries
* twice . This feels risky , but there is no known reason it should
* generate different output than the first pass . Even if it does , the
* worst - case scenario is that restore . sql might have different statistics
* data than the archive .
*/
if ( ! restarted & & te = = AH - > toc & & AH - > format = = archTar )
{
te = AH - > toc - > next ;
restarted = true ;
}
/*
* Scan the TOC for the next set of relevant stats entries . We assume
* that statistics are dumped in the order they are listed in the TOC .
* This is perhaps not the sturdiest assumption , so we verify it matches
* reality in dumpRelationStats_dumper ( ) .
*/
for ( ; te ! = AH - > toc & & count < MAX_ATTR_STATS_RELS ; te = te - > next )
{
if ( ( te - > reqs & REQ_STATS ) ! = 0 & &
strcmp ( te - > desc , " STATISTICS DATA " ) = = 0 )
{
appendPQExpBuffer ( nspnames , " %s%s " , count ? " , " : " " ,
fmtId ( te - > namespace ) ) ;
appendPQExpBuffer ( relnames , " %s%s " , count ? " , " : " " ,
fmtId ( te - > tag ) ) ;
count + + ;
}
}
/* Execute the query for the next batch of relations. */
if ( count > 0 )
{
PQExpBuffer query = createPQExpBuffer ( ) ;
appendPQExpBuffer ( query , " EXECUTE getAttributeStats( "
" '{%s}'::pg_catalog.name[], "
" '{%s}'::pg_catalog.name[]) " ,
nspnames - > data , relnames - > data ) ;
res = ExecuteSqlQuery ( fout , query - > data , PGRES_TUPLES_OK ) ;
destroyPQExpBuffer ( query ) ;
}
destroyPQExpBuffer ( nspnames ) ;
destroyPQExpBuffer ( relnames ) ;
return res ;
}
/*
* dumpRelationStats_dumper - -
*
@ -10561,14 +10635,16 @@ appendNamedArgument(PQExpBuffer out, Archive *fout, const char *argname,
* dumped .
*/
static char *
dumpRelationStats_dumper ( Archive * fout , const void * userArg )
dumpRelationStats_dumper ( Archive * fout , const void * userArg , const TocEntry * te )
{
const RelStatsInfo * rsinfo = ( RelStatsInfo * ) userArg ;
const DumpableObject * dobj = & rsinfo - > dobj ;
PGresult * res ;
static PGresult * res ;
static int rownum ;
PQExpBuffer query ;
PQExpBufferData out_data ;
PQExpBuffer out = & out_data ;
int i_schemaname ;
int i_tablename ;
int i_attname ;
int i_inherited ;
int i_null_frac ;
@ -10584,13 +10660,31 @@ dumpRelationStats_dumper(Archive *fout, const void *userArg)
int i_range_length_histogram ;
int i_range_empty_frac ;
int i_range_bounds_histogram ;
static TocEntry * expected_te ;
/*
* fetchAttributeStats ( ) assumes that the statistics are dumped in the
* order they are listed in the TOC . We verify that here for safety .
*/
if ( ! expected_te )
expected_te = ( ( ArchiveHandle * ) fout ) - > toc ;
expected_te = expected_te - > next ;
while ( ( expected_te - > reqs & REQ_STATS ) = = 0 | |
strcmp ( expected_te - > desc , " STATISTICS DATA " ) ! = 0 )
expected_te = expected_te - > next ;
if ( te ! = expected_te )
pg_fatal ( " stats dumped out of order (current: %d %s %s) (expected: %d %s %s) " ,
te - > dumpId , te - > desc , te - > tag ,
expected_te - > dumpId , expected_te - > desc , expected_te - > tag ) ;
query = createPQExpBuffer ( ) ;
if ( ! fout - > is_prepared [ PREPQUERY_GETATTRIBUTESTATS ] )
{
appendPQExpBufferStr ( query ,
" PREPARE getAttributeStats(pg_catalog.name, pg_catalog.name) AS \n "
" SELECT s.attname, s.inherited, "
" PREPARE getAttributeStats(pg_catalog.name[] , pg_catalog.name[] ) AS \n "
" SELECT s.schemaname, s.tablename, s. attname, s.inherited, "
" s.null_frac, s.avg_width, s.n_distinct, "
" s.most_common_vals, s.most_common_freqs, "
" s.histogram_bounds, s.correlation, "
@ -10608,11 +10702,21 @@ dumpRelationStats_dumper(Archive *fout, const void *userArg)
" NULL AS range_empty_frac, "
" NULL AS range_bounds_histogram " ) ;
/*
* The results must be in the order of the relations supplied in the
* parameters to ensure we remain in sync as we walk through the TOC .
* The redundant filter clause on s . tablename = ANY ( . . . ) seems
* sufficient to convince the planner to use
* pg_class_relname_nsp_index , which avoids a full scan of pg_stats .
* This may not work for all versions .
*/
appendPQExpBufferStr ( query ,
" FROM pg_catalog.pg_stats s "
" WHERE s.schemaname = $1 "
" AND s.tablename = $2 "
" ORDER BY s.attname, s.inherited " ) ;
" JOIN unnest($1, $2) WITH ORDINALITY AS u (schemaname, tablename, ord) "
" ON s.schemaname = u.schemaname "
" AND s.tablename = u.tablename "
" WHERE s.tablename = ANY($2) "
" ORDER BY u.ord, s.attname, s.inherited " ) ;
ExecuteSqlStatement ( fout , query - > data ) ;
@ -10642,16 +10746,16 @@ dumpRelationStats_dumper(Archive *fout, const void *userArg)
appendPQExpBufferStr ( out , " \n ); \n " ) ;
/* Fetch the next batch of attribute statistics if needed. */
if ( rownum > = PQntuples ( res ) )
{
PQclear ( res ) ;
res = fetchAttributeStats ( fout ) ;
rownum = 0 ;
}
/* fetch attribute stats */
appendPQExpBufferStr ( query , " EXECUTE getAttributeStats( " ) ;
appendStringLiteralAH ( query , dobj - > namespace - > dobj . name , fout ) ;
appendPQExpBufferStr ( query , " , " ) ;
appendStringLiteralAH ( query , dobj - > name , fout ) ;
appendPQExpBufferStr ( query , " ); " ) ;
res = ExecuteSqlQuery ( fout , query - > data , PGRES_TUPLES_OK ) ;
i_schemaname = PQfnumber ( res , " schemaname " ) ;
i_tablename = PQfnumber ( res , " tablename " ) ;
i_attname = PQfnumber ( res , " attname " ) ;
i_inherited = PQfnumber ( res , " inherited " ) ;
i_null_frac = PQfnumber ( res , " null_frac " ) ;
@ -10669,10 +10773,15 @@ dumpRelationStats_dumper(Archive *fout, const void *userArg)
i_range_bounds_histogram = PQfnumber ( res , " range_bounds_histogram " ) ;
/* restore attribute stats */
for ( int rownum = 0 ; rownum < PQntuples ( res ) ; rownum + + )
for ( ; rownum < PQntuples ( res ) ; rownum + + )
{
const char * attname ;
/* Stop if the next stat row in our cache isn't for this relation. */
if ( strcmp ( te - > tag , PQgetvalue ( res , rownum , i_tablename ) ) ! = 0 | |
strcmp ( te - > namespace , PQgetvalue ( res , rownum , i_schemaname ) ) ! = 0 )
break ;
appendPQExpBufferStr ( out , " SELECT * FROM pg_catalog.pg_restore_attribute_stats( \n " ) ;
appendPQExpBuffer ( out , " \t 'version', '%u'::integer, \n " ,
fout - > remoteVersion ) ;
@ -10762,8 +10871,6 @@ dumpRelationStats_dumper(Archive *fout, const void *userArg)
appendPQExpBufferStr ( out , " \n ); \n " ) ;
}
PQclear ( res ) ;
destroyPQExpBuffer ( query ) ;
return out - > data ;
}
Nathan Bossart
3 months ago