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mirror of https://github.com/postgres/postgres.git synced 2025-07-02 09:02:37 +03:00

Instead of having a configure-time DEFAULT_ATTSTATTARGET, store -1 in

attstattarget to indicate 'use the default'.  The default is now a GUC
variable default_statistics_target, and so may be changed on the fly.  Along
the way we gain the ability to have pg_dump dump the per-column statistics
target when it's not the default.  Patch by Neil Conway, with some kibitzing
from Tom Lane.
This commit is contained in:
Tom Lane
2002-07-31 17:19:54 +00:00
parent 8be3cfbbd5
commit ce7565ab91
18 changed files with 125 additions and 60 deletions

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/commands/analyze.c,v 1.38 2002/06/20 20:29:26 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/commands/analyze.c,v 1.39 2002/07/31 17:19:51 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -107,6 +107,11 @@ typedef struct
#define swapInt(a,b) do {int _tmp; _tmp=a; a=b; b=_tmp;} while(0)
#define swapDatum(a,b) do {Datum _tmp; _tmp=a; a=b; b=_tmp;} while(0)
/* Default statistics target (GUC parameter) */
int default_statistics_target = 10;
static int elevel = -1;
static MemoryContext anl_context = NULL;
@ -384,7 +389,7 @@ examine_attribute(Relation onerel, int attnum)
VacAttrStats *stats;
/* Don't analyze column if user has specified not to */
if (attr->attstattarget <= 0)
if (attr->attstattarget == 0)
return NULL;
/* If column has no "=" operator, we can't do much of anything */
@ -425,6 +430,10 @@ examine_attribute(Relation onerel, int attnum)
stats->eqopr = eqopr;
stats->eqfunc = eqfunc;
/* If the attstattarget column is negative, use the default value */
if (stats->attr->attstattarget < 0)
stats->attr->attstattarget = default_statistics_target;
/* Is there a "<" operator with suitable semantics? */
func_operator = compatible_oper(makeList1(makeString("<")),
attr->atttypid,
@ -466,14 +475,14 @@ examine_attribute(Relation onerel, int attnum)
* know it at this point.
*--------------------
*/
stats->minrows = 300 * attr->attstattarget;
stats->minrows = 300 * stats->attr->attstattarget;
}
else
{
/* Can't do much but the minimal stuff */
stats->algcode = ALG_MINIMAL;
/* Might as well use the same minrows as above */
stats->minrows = 300 * attr->attstattarget;
stats->minrows = 300 * stats->attr->attstattarget;
}
return stats;