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Support ALTER TABLESPACE name SET/RESET ( tablespace_options ).

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This patch only supports seq_page_cost and random_page_cost as parameters,
but it provides the infrastructure to scalably support many more.
In particular, we may want to add support for effective_io_concurrency,
but I'm leaving that as future work for now.

Thanks to Tom Lane for design help and Alvaro Herrera for the review.
This commit is contained in:
Robert Haas
2010-01-05 21:54:00 +00:00
parent 72559b49c0
commit d86d51a958
28 changed files with 588 additions and 101 deletions
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26
src/backend/utils/adt/selfuncs.c
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@ -15,7 +15,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.267 2010/01/04 02:44:39 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.268 2010/01/05 21:53:59 rhaas Exp $
*
*-------------------------------------------------------------------------
*/
@ -119,6 +119,7 @@
#include "utils/nabstime.h"
#include "utils/pg_locale.h"
#include "utils/selfuncs.h"
#include "utils/spccache.h"
#include "utils/syscache.h"
#include "utils/tqual.h"
@ -5648,6 +5649,7 @@ genericcostestimate(PlannerInfo *root,
QualCost index_qual_cost;
double qual_op_cost;
double qual_arg_cost;
double spc_random_page_cost;
List *selectivityQuals;
ListCell *l;
@ -5756,6 +5758,11 @@ genericcostestimate(PlannerInfo *root,
else
numIndexPages = 1.0;
/* fetch estimated page cost for schema containing index */
get_tablespace_page_costs(index->reltablespace,
&spc_random_page_cost,
NULL);
/*
* Now compute the disk access costs.
*
@ -5802,15 +5809,16 @@ genericcostestimate(PlannerInfo *root,
* share for each outer scan. (Don't pro-rate for ScalarArrayOpExpr,
* since that's internal to the indexscan.)
*/
*indexTotalCost = (pages_fetched * random_page_cost) / num_outer_scans;
*indexTotalCost = (pages_fetched * spc_random_page_cost)
/ num_outer_scans;
}
else
{
/*
* For a single index scan, we just charge random_page_cost per page
* touched.
* For a single index scan, we just charge spc_random_page_cost per
* page touched.
*/
*indexTotalCost = numIndexPages * random_page_cost;
*indexTotalCost = numIndexPages * spc_random_page_cost;
}
/*
@ -5825,11 +5833,11 @@ genericcostestimate(PlannerInfo *root,
*
* We can deal with this by adding a very small "fudge factor" that
* depends on the index size. The fudge factor used here is one
* random_page_cost per 100000 index pages, which should be small enough
* to not alter index-vs-seqscan decisions, but will prevent indexes of
* different sizes from looking exactly equally attractive.
* spc_random_page_cost per 100000 index pages, which should be small
* enough to not alter index-vs-seqscan decisions, but will prevent
* indexes of different sizes from looking exactly equally attractive.
*/
*indexTotalCost += index->pages * random_page_cost / 100000.0;
*indexTotalCost += index->pages * spc_random_page_cost / 100000.0;
/*
* CPU cost: any complex expressions in the indexquals will need to be