mirror of
https://github.com/postgres/postgres.git
synced 2025-11-03 09:13:20 +03:00
9ee014fc89
Module provides new access method. It is actually a simple Bloom filter implemented as pgsql's index. It could give some benefits on search with large number of columns. Module is a single way to test generic WAL interface committed earlier. Author: Teodor Sigaev, Alexander Korotkov Reviewers: Aleksander Alekseev, Michael Paquier, Jim Nasby
49 lines
1.2 KiB
C
49 lines
1.2 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* blcost.c
|
|
* Cost estimate function for bloom indexes.
|
|
*
|
|
* Copyright (c) 2016, PostgreSQL Global Development Group
|
|
*
|
|
* IDENTIFICATION
|
|
* contrib/bloom/blcost.c
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
#include "postgres.h"
|
|
|
|
#include "fmgr.h"
|
|
#include "optimizer/cost.h"
|
|
#include "utils/selfuncs.h"
|
|
|
|
#include "bloom.h"
|
|
|
|
/*
|
|
* Estimate cost of bloom index scan.
|
|
*/
|
|
void
|
|
blcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
|
|
Cost *indexStartupCost, Cost *indexTotalCost,
|
|
Selectivity *indexSelectivity, double *indexCorrelation)
|
|
{
|
|
IndexOptInfo *index = path->indexinfo;
|
|
List *qinfos;
|
|
GenericCosts costs;
|
|
|
|
/* Do preliminary analysis of indexquals */
|
|
qinfos = deconstruct_indexquals(path);
|
|
|
|
MemSet(&costs, 0, sizeof(costs));
|
|
|
|
/* We have to visit all index tuples anyway */
|
|
costs.numIndexTuples = index->tuples;
|
|
|
|
/* Use generic estimate */
|
|
genericcostestimate(root, path, loop_count, qinfos, &costs);
|
|
|
|
*indexStartupCost = costs.indexStartupCost;
|
|
*indexTotalCost = costs.indexTotalCost;
|
|
*indexSelectivity = costs.indexSelectivity;
|
|
*indexCorrelation = costs.indexCorrelation;
|
|
}
|