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First step in fixing selectivity-estimation code. eqsel and

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neqsel now behave as per my suggestions in pghackers a few days ago.
selectivity for < > <= >= should work OK for integral types as well, but
still need work for nonintegral types.  Since these routines have never
actually executed before :-(, this may result in some significant changes
in the optimizer's choices of execution plans.  Let me know if you see
any serious misbehavior.
CAUTION: THESE CHANGES REQUIRE INITDB.  pg_statistic table has changed.
This commit is contained in:
Tom Lane
1999-08-01 04:54:25 +00:00
parent f851c6b07d
commit 44878506d8
5 changed files with 542 additions and 206 deletions
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68
src/backend/commands/vacuum.c
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@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.115 1999/07/19 07:07:20 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.116 1999/08/01 04:54:24 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -78,7 +78,7 @@ static void vc_vacpage(Page page, VPageDescr vpd);
static void vc_vaconeind(VPageList vpl, Relation indrel, int num_tuples, int keep_tuples);
static void vc_scanoneind(Relation indrel, int num_tuples);
static void vc_attrstats(Relation onerel, VRelStats *vacrelstats, HeapTuple tuple);
static void vc_bucketcpy(Form_pg_attribute attr, Datum value, Datum *bucket, int16 *bucket_len);
static void vc_bucketcpy(Form_pg_attribute attr, Datum value, Datum *bucket, int *bucket_len);
static void vc_updstats(Oid relid, int num_pages, int num_tuples, bool hasindex, VRelStats *vacrelstats);
static void vc_delhilowstats(Oid relid, int attcnt, int *attnums);
static VPageDescr vc_tidreapped(ItemPointer itemptr, VPageList vpl);
@@ -473,9 +473,13 @@ vc_vacone(Oid relid, bool analyze, List *va_cols)
{
pgopform = (Form_pg_operator) GETSTRUCT(func_operator);
fmgr_info(pgopform->oprcode, &(stats->f_cmplt));
stats->op_cmplt = oprid(func_operator);
}
else
{
stats->f_cmplt.fn_addr = NULL;
stats->op_cmplt = InvalidOid;
}
func_operator = oper(">", stats->attr->atttypid, stats->attr->atttypid, true);
if (func_operator != NULL)
@@ -2200,8 +2204,8 @@ vc_attrstats(Relation onerel, VRelStats *vacrelstats, HeapTuple tuple)
{
swapDatum(stats->guess1, stats->guess2);
swapInt(stats->guess1_len, stats->guess2_len);
stats->guess1_cnt = stats->guess2_hits;
swapLong(stats->guess1_hits, stats->guess2_hits);
stats->guess1_cnt = stats->guess1_hits;
}
if (stats->guess1_cnt > stats->best_cnt)
{
@@ -2227,7 +2231,7 @@ vc_attrstats(Relation onerel, VRelStats *vacrelstats, HeapTuple tuple)
*
*/
static void
vc_bucketcpy(Form_pg_attribute attr, Datum value, Datum *bucket, int16 *bucket_len)
vc_bucketcpy(Form_pg_attribute attr, Datum value, Datum *bucket, int *bucket_len)
{
if (attr->attbyval && attr->attlen != -1)
*bucket = value;
@@ -2340,13 +2344,14 @@ vc_updstats(Oid relid, int num_pages, int num_tuples, bool hasindex, VRelStats *
selratio = 0;
else if (VacAttrStatsLtGtValid(stats) && stats->min_cnt + stats->max_cnt == stats->nonnull_cnt)
{
/* exact result when there are just 1 or 2 values... */
double min_cnt_d = stats->min_cnt,
max_cnt_d = stats->max_cnt,
null_cnt_d = stats->null_cnt,
nonnullcnt_d = stats->nonnull_cnt; /* prevent overflow */
nonnull_cnt_d = stats->nonnull_cnt; /* prevent overflow */
selratio = (min_cnt_d * min_cnt_d + max_cnt_d * max_cnt_d + null_cnt_d * null_cnt_d) /
(nonnullcnt_d + null_cnt_d) / (nonnullcnt_d + null_cnt_d);
(nonnull_cnt_d + null_cnt_d) / (nonnull_cnt_d + null_cnt_d);
}
else
{
@@ -2359,7 +2364,9 @@ vc_updstats(Oid relid, int num_pages, int num_tuples, bool hasindex, VRelStats *
*/
selratio = (most * most + 0.20 * most * (total - most)) / total / total;
}
if (selratio > 1.0)
if (selratio < 0.0)
selratio = 0.0;
else if (selratio > 1.0)
selratio = 1.0;
attp->attdisbursion = selratio;
@@ -2375,13 +2382,22 @@ vc_updstats(Oid relid, int num_pages, int num_tuples, bool hasindex, VRelStats *
* doing system relations, especially pg_statistic is a
* problem
*/
if (VacAttrStatsLtGtValid(stats) && stats->initialized /* &&
* !IsSystemRelationName(
*
pgcform->relname.data) */ )
if (VacAttrStatsLtGtValid(stats) && stats->initialized
/* && !IsSystemRelationName(pgcform->relname.data)
*/ )
{
float32data nullratio;
float32data bestratio;
FmgrInfo out_function;
char *out_string;
double best_cnt_d = stats->best_cnt,
null_cnt_d = stats->null_cnt,
nonnull_cnt_d = stats->nonnull_cnt; /* prevent overflow */
nullratio = null_cnt_d / (nonnull_cnt_d + null_cnt_d);
bestratio = best_cnt_d / (nonnull_cnt_d + null_cnt_d);
fmgr_info(stats->outfunc, &out_function);
for (i = 0; i < Natts_pg_statistic; ++i)
nulls[i] = ' ';
@@ -2391,26 +2407,34 @@ vc_updstats(Oid relid, int num_pages, int num_tuples, bool hasindex, VRelStats *
* ----------------
*/
i = 0;
values[i++] = (Datum) relid; /* 1 */
values[i++] = (Datum) attp->attnum; /* 2 */
values[i++] = (Datum) InvalidOid; /* 3 */
fmgr_info(stats->outfunc, &out_function);
out_string = (*fmgr_faddr(&out_function)) (stats->min, stats->attr->atttypid);
values[i++] = (Datum) fmgr(F_TEXTIN, out_string);
values[i++] = (Datum) relid; /* starelid */
values[i++] = (Datum) attp->attnum; /* staattnum */
values[i++] = (Datum) stats->op_cmplt; /* staop */
/* hack: this code knows float4 is pass-by-ref */
values[i++] = PointerGetDatum(&nullratio); /* stanullfrac */
values[i++] = PointerGetDatum(&bestratio); /* stacommonfrac */
out_string = (*fmgr_faddr(&out_function)) (stats->best, stats->attr->atttypid, stats->attr->atttypmod);
values[i++] = PointerGetDatum(textin(out_string)); /* stacommonval */
pfree(out_string);
out_string = (char *) (*fmgr_faddr(&out_function)) (stats->max, stats->attr->atttypid);
values[i++] = (Datum) fmgr(F_TEXTIN, out_string);
out_string = (*fmgr_faddr(&out_function)) (stats->min, stats->attr->atttypid, stats->attr->atttypmod);
values[i++] = PointerGetDatum(textin(out_string)); /* staloval */
pfree(out_string);
out_string = (char *) (*fmgr_faddr(&out_function)) (stats->max, stats->attr->atttypid, stats->attr->atttypmod);
values[i++] = PointerGetDatum(textin(out_string)); /* stahival */
pfree(out_string);
stup = heap_formtuple(sd->rd_att, values, nulls);
/* ----------------
* insert the tuple in the relation and get the tuple's oid.
* insert the tuple in the relation.
* ----------------
*/
heap_insert(sd, stup);
pfree(DatumGetPointer(values[3]));
pfree(DatumGetPointer(values[4]));
/* release allocated space */
pfree(DatumGetPointer(values[Anum_pg_statistic_stacommonval-1]));
pfree(DatumGetPointer(values[Anum_pg_statistic_staloval-1]));
pfree(DatumGetPointer(values[Anum_pg_statistic_stahival-1]));
pfree(stup);
}
}