/*
* Fills in the relation statistics for an append-only relation.
*
* This information is used to update the reltuples and relpages information
* in pg_class. reltuples is the same as "pg_aoseg_<oid>:tupcount"
* column and we simulate relpages by subdividing the eof value
* ("pg_aoseg_<oid>:eof") over the defined page size.
*/
void
vacuum_appendonly_fill_stats(Relation aorel, Snapshot snapshot,
BlockNumber *rel_pages, double *rel_tuples,
bool *relhasindex)
{
FileSegTotals *fstotal;
BlockNumber nblocks;
char *relname;
double num_tuples;
double totalbytes;
double eof;
int64 hidden_tupcount;
AppendOnlyVisimap visimap;
Assert(RelationIsAoRows(aorel) || RelationIsAoCols(aorel));
relname = RelationGetRelationName(aorel);
/* get updated statistics from the pg_aoseg table */
if (RelationIsAoRows(aorel))
{
fstotal = GetSegFilesTotals(aorel, snapshot);
}
else
{
Assert(RelationIsAoCols(aorel));
fstotal = GetAOCSSSegFilesTotals(aorel, snapshot);
}
/* calculate the values we care about */
eof = (double)fstotal->totalbytes;
num_tuples = (double)fstotal->totaltuples;
totalbytes = eof;
nblocks = (uint32)RelationGuessNumberOfBlocks(totalbytes);
AppendOnlyVisimap_Init(&visimap,
aorel->rd_appendonly->visimaprelid,
aorel->rd_appendonly->visimapidxid,
AccessShareLock,
snapshot);
hidden_tupcount = AppendOnlyVisimap_GetRelationHiddenTupleCount(&visimap);
num_tuples -= hidden_tupcount;
Assert(num_tuples > -1.0);
AppendOnlyVisimap_Finish(&visimap, AccessShareLock);
elogif (Debug_appendonly_print_compaction, LOG,
"Gather statistics after vacuum for append-only relation %s: "
"page count %d, tuple count %f",
relname,
nblocks, num_tuples);
*rel_pages = nblocks;
*rel_tuples = num_tuples;
*relhasindex = aorel->rd_rel->relhasindex;
ereport(elevel,
(errmsg("\"%s\": found %.0f rows in %u pages.",
relname, num_tuples, nblocks)));
pfree(fstotal);
}
static void gp_statistics_estimate_reltuples_relpages_ao_rows(Relation rel, float4 *reltuples, float4 *relpages)
{
FileSegTotals *fstotal;
AppendOnlyEntry *aoEntry;
AppendOnlyVisimap visimap;
int64 hidden_tupcount = 0;
/**
* Ensure that the right kind of relation with the right type of storage is passed to us.
*/
Assert(rel->rd_rel->relkind == RELKIND_RELATION);
Assert(RelationIsAoRows(rel));
fstotal = GetSegFilesTotals(rel, SnapshotNow);
Assert(fstotal);
/**
* The planner doesn't understand AO's blocks, so need this method to try to fudge up a number for
* the planner.
*/
*relpages = RelationGuessNumberOfBlocks((double)fstotal->totalbytes);
aoEntry = GetAppendOnlyEntry(RelationGetRelid(rel), SnapshotNow);
AppendOnlyVisimap_Init(&visimap, aoEntry->visimaprelid, aoEntry->visimapidxid, AccessShareLock, SnapshotNow);
hidden_tupcount = AppendOnlyVisimap_GetRelationHiddenTupleCount(&visimap);
AppendOnlyVisimap_Finish(&visimap, AccessShareLock);
/**
* The number of tuples in AO table is known accurately. Therefore, we just utilize this value.
*/
*reltuples = (double)(fstotal->totaltuples - hidden_tupcount);
pfree(fstotal);
pfree(aoEntry);
return;
}
