mirror of
https://github.com/postgres/postgres.git
synced 2025-07-27 12:41:57 +03:00
Add proofreader's changes to docs.
Fix misspelling of disbursion to dispersion.
This commit is contained in:
Bruce Momjian
@ -8,7 +8,7 @@
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/access/common/tupdesc.c,v 1.66 2000/07/03 23:09:10 wieck Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/access/common/tupdesc.c,v 1.67 2000/10/05 19:48:20 momjian Exp $
|
||||
*
|
||||
* NOTES
|
||||
* some of the executor utility code such as "ExecTypeFromTL" should be
|
||||
@ -239,7 +239,7 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2)
|
||||
|
||||
/*
|
||||
* We do not need to check every single field here, and in fact
|
||||
* some fields such as attdisbursion probably shouldn't be
|
||||
* some fields such as attdispersion probably shouldn't be
|
||||
* compared.
|
||||
*/
|
||||
if (strcmp(NameStr(attr1->attname), NameStr(attr2->attname)) != 0)
|
||||
@ -348,7 +348,7 @@ TupleDescInitEntry(TupleDesc desc,
|
||||
MemSet(NameStr(att->attname), 0, NAMEDATALEN);
|
||||
|
||||
|
||||
att->attdisbursion = 0; /* dummy value */
|
||||
att->attdispersion = 0; /* dummy value */
|
||||
att->attcacheoff = -1;
|
||||
att->atttypmod = typmod;
|
||||
|
||||
|
||||
@ -8,7 +8,7 @@
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.146 2000/09/30 18:28:53 tgl Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.147 2000/10/05 19:48:21 momjian Exp $
|
||||
*
|
||||
*
|
||||
* INTERFACE ROUTINES
|
||||
@ -360,7 +360,7 @@ heap_storage_create(Relation rel)
|
||||
* work? Is it automatic now? Expects the caller to have
|
||||
* attname, atttypid, atttyparg, attproc, and attlen domains filled.
|
||||
* Create fills the attnum domains sequentually from zero,
|
||||
* fills the attdisbursion domains with zeros, and fills the
|
||||
* fills the attdispersion domains with zeros, and fills the
|
||||
* attrelid fields with the relid.
|
||||
*
|
||||
* scan relation catalog for name conflict
|
||||
@ -564,7 +564,7 @@ AddNewAttributeTuples(Oid new_rel_oid,
|
||||
for (i = 0; i < natts; i++)
|
||||
{
|
||||
(*dpp)->attrelid = new_rel_oid;
|
||||
(*dpp)->attdisbursion = 0;
|
||||
(*dpp)->attdispersion = 0;
|
||||
|
||||
tup = heap_addheader(Natts_pg_attribute,
|
||||
ATTRIBUTE_TUPLE_SIZE,
|
||||
@ -587,7 +587,7 @@ AddNewAttributeTuples(Oid new_rel_oid,
|
||||
for (i = 0; i < -1 - FirstLowInvalidHeapAttributeNumber; i++)
|
||||
{
|
||||
(*dpp)->attrelid = new_rel_oid;
|
||||
/* (*dpp)->attdisbursion = 0; unneeded */
|
||||
/* (*dpp)->attdispersion = 0; unneeded */
|
||||
|
||||
tup = heap_addheader(Natts_pg_attribute,
|
||||
ATTRIBUTE_TUPLE_SIZE,
|
||||
|
||||
@ -8,7 +8,7 @@
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/catalog/index.c,v 1.126 2000/07/14 22:17:41 tgl Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/catalog/index.c,v 1.127 2000/10/05 19:48:21 momjian Exp $
|
||||
*
|
||||
*
|
||||
* INTERFACE ROUTINES
|
||||
@ -305,7 +305,7 @@ ConstructTupleDescriptor(Oid heapoid,
|
||||
*/
|
||||
((Form_pg_attribute) to)->attnum = i + 1;
|
||||
|
||||
((Form_pg_attribute) to)->attdisbursion = 0.0;
|
||||
((Form_pg_attribute) to)->attdispersion = 0.0;
|
||||
((Form_pg_attribute) to)->attnotnull = false;
|
||||
((Form_pg_attribute) to)->atthasdef = false;
|
||||
((Form_pg_attribute) to)->attcacheoff = -1;
|
||||
|
||||
@ -8,7 +8,7 @@
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/commands/analyze.c,v 1.6 2000/09/06 14:15:16 petere Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/commands/analyze.c,v 1.7 2000/10/05 19:48:22 momjian Exp $
|
||||
*
|
||||
|
||||
*-------------------------------------------------------------------------
|
||||
@ -439,13 +439,13 @@ update_attstats(Oid relid, int natts, VacAttrStats *vacattrstats)
|
||||
float4 selratio; /* average ratio of rows selected
|
||||
* for a random constant */
|
||||
|
||||
/* Compute disbursion */
|
||||
/* Compute dispersion */
|
||||
if (stats->nonnull_cnt == 0 && stats->null_cnt == 0)
|
||||
{
|
||||
|
||||
/*
|
||||
* empty relation, so put a dummy value in
|
||||
* attdisbursion
|
||||
* attdispersion
|
||||
*/
|
||||
selratio = 0;
|
||||
}
|
||||
@ -455,9 +455,9 @@ update_attstats(Oid relid, int natts, VacAttrStats *vacattrstats)
|
||||
* looks like we have a unique-key attribute --- flag
|
||||
* this with special -1.0 flag value.
|
||||
*
|
||||
* The correct disbursion is 1.0/numberOfRows, but since
|
||||
* The correct dispersion is 1.0/numberOfRows, but since
|
||||
* the relation row count can get updated without
|
||||
* recomputing disbursion, we want to store a
|
||||
* recomputing dispersion, we want to store a
|
||||
* "symbolic" value and figure 1.0/numberOfRows on the
|
||||
* fly.
|
||||
*/
|
||||
@ -499,7 +499,7 @@ update_attstats(Oid relid, int natts, VacAttrStats *vacattrstats)
|
||||
}
|
||||
|
||||
/* overwrite the existing statistics in the tuple */
|
||||
attp->attdisbursion = selratio;
|
||||
attp->attdispersion = selratio;
|
||||
|
||||
/* invalidate the tuple in the cache and write the buffer */
|
||||
RelationInvalidateHeapTuple(ad, atup);
|
||||
|
||||
@ -8,7 +8,7 @@
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.104 2000/09/29 18:21:26 tgl Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.105 2000/10/05 19:48:22 momjian Exp $
|
||||
*
|
||||
* NOTES
|
||||
* The PerformAddAttribute() code, like most of the relation
|
||||
@ -459,7 +459,7 @@ AlterTableAddColumn(const char *relationName,
|
||||
namestrcpy(&(attribute->attname), colDef->colname);
|
||||
attribute->atttypid = typeTuple->t_data->t_oid;
|
||||
attribute->attlen = tform->typlen;
|
||||
attribute->attdisbursion = 0;
|
||||
attribute->attdispersion = 0;
|
||||
attribute->attcacheoff = -1;
|
||||
attribute->atttypmod = colDef->typename->typmod;
|
||||
attribute->attnum = i;
|
||||
|
||||
@ -8,7 +8,7 @@
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.166 2000/09/19 19:30:03 tgl Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.167 2000/10/05 19:48:22 momjian Exp $
|
||||
*
|
||||
|
||||
*-------------------------------------------------------------------------
|
||||
@ -2124,10 +2124,10 @@ tid_reaped(ItemPointer itemptr, VacPageList vacpagelist)
|
||||
*
|
||||
* Statistics are stored in several places: the pg_class row for the
|
||||
* relation has stats about the whole relation, the pg_attribute rows
|
||||
* for each attribute store "disbursion", and there is a pg_statistic
|
||||
* row for each (non-system) attribute. (Disbursion probably ought to
|
||||
* for each attribute store "dispersion", and there is a pg_statistic
|
||||
* row for each (non-system) attribute. (Dispersion probably ought to
|
||||
* be moved to pg_statistic, but it's not worth doing unless there's
|
||||
* another reason to have to change pg_attribute.) Disbursion and
|
||||
* another reason to have to change pg_attribute.) Dispersion and
|
||||
* pg_statistic values are only updated by VACUUM ANALYZE, but we
|
||||
* always update the stats in pg_class.
|
||||
*
|
||||
|
||||
@ -8,7 +8,7 @@
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/executor/execUtils.c,v 1.66 2000/09/12 21:06:48 tgl Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/executor/execUtils.c,v 1.67 2000/10/05 19:48:25 momjian Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
@ -567,7 +567,7 @@ ExecSetTypeInfo(int index,
|
||||
|
||||
att->atttypid = typeID;
|
||||
att->attdefrel = 0; /* dummy value */
|
||||
att->attdisbursion = 0; /* dummy value */
|
||||
att->attdispersion = 0; /* dummy value */
|
||||
att->atttyparg = 0; /* dummy value */
|
||||
att->attlen = attLen;
|
||||
att->attnum = attNum;
|
||||
|
||||
@ -42,7 +42,7 @@
|
||||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/costsize.c,v 1.63 2000/09/29 18:21:32 tgl Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/costsize.c,v 1.64 2000/10/05 19:48:26 momjian Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
@ -571,7 +571,7 @@ cost_mergejoin(Path *path,
|
||||
* 'outer_path' is the path for the outer relation
|
||||
* 'inner_path' is the path for the inner relation
|
||||
* 'restrictlist' are the RestrictInfo nodes to be applied at the join
|
||||
* 'innerdisbursion' is an estimate of the disbursion statistic
|
||||
* 'innerdispersion' is an estimate of the dispersion statistic
|
||||
* for the inner hash key.
|
||||
*/
|
||||
void
|
||||
@ -579,7 +579,7 @@ cost_hashjoin(Path *path,
|
||||
Path *outer_path,
|
||||
Path *inner_path,
|
||||
List *restrictlist,
|
||||
Selectivity innerdisbursion)
|
||||
Selectivity innerdispersion)
|
||||
{
|
||||
Cost startup_cost = 0;
|
||||
Cost run_cost = 0;
|
||||
@ -609,12 +609,12 @@ cost_hashjoin(Path *path,
|
||||
* average bucket loading of NTUP_PER_BUCKET, but that goal will
|
||||
* be reached only if data values are uniformly distributed among
|
||||
* the buckets. To be conservative, we scale up the target bucket
|
||||
* size by the number of inner rows times inner disbursion, giving
|
||||
* size by the number of inner rows times inner dispersion, giving
|
||||
* an estimate of the typical number of duplicates of each value.
|
||||
* We then charge one cpu_operator_cost per tuple comparison.
|
||||
*/
|
||||
run_cost += cpu_operator_cost * outer_path->parent->rows *
|
||||
NTUP_PER_BUCKET * ceil(inner_path->parent->rows * innerdisbursion);
|
||||
NTUP_PER_BUCKET * ceil(inner_path->parent->rows * innerdispersion);
|
||||
|
||||
/*
|
||||
* Estimate the number of tuples that get through the hashing filter
|
||||
@ -649,7 +649,7 @@ cost_hashjoin(Path *path,
|
||||
/*
|
||||
* Bias against putting larger relation on inside. We don't want an
|
||||
* absolute prohibition, though, since larger relation might have
|
||||
* better disbursion --- and we can't trust the size estimates
|
||||
* better dispersion --- and we can't trust the size estimates
|
||||
* unreservedly, anyway. Instead, inflate the startup cost by the
|
||||
* square root of the size ratio. (Why square root? No real good
|
||||
* reason, but it seems reasonable...)
|
||||
|
||||
@ -8,7 +8,7 @@
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/joinpath.c,v 1.57 2000/09/29 18:21:32 tgl Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/joinpath.c,v 1.58 2000/10/05 19:48:26 momjian Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
@ -45,7 +45,7 @@ static void hash_inner_and_outer(Query *root, RelOptInfo *joinrel,
|
||||
List *restrictlist, JoinType jointype);
|
||||
static Path *best_innerjoin(List *join_paths, List *outer_relid,
|
||||
JoinType jointype);
|
||||
static Selectivity estimate_disbursion(Query *root, Var *var);
|
||||
static Selectivity estimate_dispersion(Query *root, Var *var);
|
||||
static List *select_mergejoin_clauses(RelOptInfo *joinrel,
|
||||
RelOptInfo *outerrel,
|
||||
RelOptInfo *innerrel,
|
||||
@ -637,7 +637,7 @@ hash_inner_and_outer(Query *root,
|
||||
*right,
|
||||
*inner;
|
||||
List *hashclauses;
|
||||
Selectivity innerdisbursion;
|
||||
Selectivity innerdispersion;
|
||||
|
||||
if (restrictinfo->hashjoinoperator == InvalidOid)
|
||||
continue; /* not hashjoinable */
|
||||
@ -667,8 +667,8 @@ hash_inner_and_outer(Query *root,
|
||||
/* always a one-element list of hash clauses */
|
||||
hashclauses = makeList1(restrictinfo);
|
||||
|
||||
/* estimate disbursion of inner var for costing purposes */
|
||||
innerdisbursion = estimate_disbursion(root, inner);
|
||||
/* estimate dispersion of inner var for costing purposes */
|
||||
innerdispersion = estimate_dispersion(root, inner);
|
||||
|
||||
/*
|
||||
* We consider both the cheapest-total-cost and
|
||||
@ -682,7 +682,7 @@ hash_inner_and_outer(Query *root,
|
||||
innerrel->cheapest_total_path,
|
||||
restrictlist,
|
||||
hashclauses,
|
||||
innerdisbursion));
|
||||
innerdispersion));
|
||||
if (outerrel->cheapest_startup_path != outerrel->cheapest_total_path)
|
||||
add_path(joinrel, (Path *)
|
||||
create_hashjoin_path(joinrel,
|
||||
@ -691,7 +691,7 @@ hash_inner_and_outer(Query *root,
|
||||
innerrel->cheapest_total_path,
|
||||
restrictlist,
|
||||
hashclauses,
|
||||
innerdisbursion));
|
||||
innerdispersion));
|
||||
}
|
||||
}
|
||||
|
||||
@ -759,7 +759,7 @@ best_innerjoin(List *join_paths, Relids outer_relids, JoinType jointype)
|
||||
}
|
||||
|
||||
/*
|
||||
* Estimate disbursion of the specified Var
|
||||
* Estimate dispersion of the specified Var
|
||||
*
|
||||
* We use a default of 0.1 if we can't figure out anything better.
|
||||
* This will typically discourage use of a hash rather strongly,
|
||||
@ -768,7 +768,7 @@ best_innerjoin(List *join_paths, Relids outer_relids, JoinType jointype)
|
||||
* seem much worse).
|
||||
*/
|
||||
static Selectivity
|
||||
estimate_disbursion(Query *root, Var *var)
|
||||
estimate_dispersion(Query *root, Var *var)
|
||||
{
|
||||
Oid relid;
|
||||
|
||||
@ -780,7 +780,7 @@ estimate_disbursion(Query *root, Var *var)
|
||||
if (relid == InvalidOid)
|
||||
return 0.1;
|
||||
|
||||
return (Selectivity) get_attdisbursion(relid, var->varattno, 0.1);
|
||||
return (Selectivity) get_attdispersion(relid, var->varattno, 0.1);
|
||||
}
|
||||
|
||||
/*
|
||||
|
||||
@ -8,7 +8,7 @@
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/pathnode.c,v 1.66 2000/09/29 18:21:23 tgl Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/pathnode.c,v 1.67 2000/10/05 19:48:27 momjian Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
@ -522,7 +522,7 @@ create_mergejoin_path(RelOptInfo *joinrel,
|
||||
* 'restrict_clauses' are the RestrictInfo nodes to apply at the join
|
||||
* 'hashclauses' is a list of the hash join clause (always a 1-element list)
|
||||
* (this should be a subset of the restrict_clauses list)
|
||||
* 'innerdisbursion' is an estimate of the disbursion of the inner hash key
|
||||
* 'innerdispersion' is an estimate of the dispersion of the inner hash key
|
||||
*
|
||||
*/
|
||||
HashPath *
|
||||
@ -532,7 +532,7 @@ create_hashjoin_path(RelOptInfo *joinrel,
|
||||
Path *inner_path,
|
||||
List *restrict_clauses,
|
||||
List *hashclauses,
|
||||
Selectivity innerdisbursion)
|
||||
Selectivity innerdispersion)
|
||||
{
|
||||
HashPath *pathnode = makeNode(HashPath);
|
||||
|
||||
@ -550,7 +550,7 @@ create_hashjoin_path(RelOptInfo *joinrel,
|
||||
outer_path,
|
||||
inner_path,
|
||||
restrict_clauses,
|
||||
innerdisbursion);
|
||||
innerdispersion);
|
||||
|
||||
return pathnode;
|
||||
}
|
||||
|
||||
@ -15,7 +15,7 @@
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.79 2000/09/15 18:45:26 tgl Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.80 2000/10/05 19:48:28 momjian Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
@ -230,11 +230,11 @@ eqsel(PG_FUNCTION_ARGS)
|
||||
|
||||
/*
|
||||
* No VACUUM ANALYZE stats available, so make a guess using
|
||||
* the disbursion stat (if we have that, which is unlikely for
|
||||
* the dispersion stat (if we have that, which is unlikely for
|
||||
* a normal attribute; but for a system attribute we may be
|
||||
* able to estimate it).
|
||||
*/
|
||||
selec = get_attdisbursion(relid, attno, 0.01);
|
||||
selec = get_attdispersion(relid, attno, 0.01);
|
||||
}
|
||||
|
||||
result = (float8) selec;
|
||||
@ -655,8 +655,8 @@ eqjoinsel(PG_FUNCTION_ARGS)
|
||||
result = DEFAULT_EQ_SEL;
|
||||
else
|
||||
{
|
||||
num1 = unknown1 ? 1.0 : get_attdisbursion(relid1, attno1, 0.01);
|
||||
num2 = unknown2 ? 1.0 : get_attdisbursion(relid2, attno2, 0.01);
|
||||
num1 = unknown1 ? 1.0 : get_attdispersion(relid1, attno1, 0.01);
|
||||
num2 = unknown2 ? 1.0 : get_attdispersion(relid2, attno2, 0.01);
|
||||
|
||||
/*
|
||||
* The join selectivity cannot be more than num2, since each tuple
|
||||
@ -666,7 +666,7 @@ eqjoinsel(PG_FUNCTION_ARGS)
|
||||
* reasoning it is not more than num1. The min is therefore an
|
||||
* upper bound.
|
||||
*
|
||||
* If we know the disbursion of only one side, use it; the reasoning
|
||||
* If we know the dispersion of only one side, use it; the reasoning
|
||||
* above still works.
|
||||
*
|
||||
* XXX can we make a better estimate here? Using the nullfrac
|
||||
|
||||
36
src/backend/utils/cache/lsyscache.c
vendored
36
src/backend/utils/cache/lsyscache.c
vendored
@ -7,7 +7,7 @@
|
||||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/utils/cache/lsyscache.c,v 1.45 2000/08/13 02:50:16 tgl Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/utils/cache/lsyscache.c,v 1.46 2000/10/05 19:48:29 momjian Exp $
|
||||
*
|
||||
* NOTES
|
||||
* Eventually, the index information should go through here, too.
|
||||
@ -168,9 +168,9 @@ get_atttypmod(Oid relid, AttrNumber attnum)
|
||||
}
|
||||
|
||||
/*
|
||||
* get_attdisbursion
|
||||
* get_attdispersion
|
||||
*
|
||||
* Retrieve the disbursion statistic for an attribute,
|
||||
* Retrieve the dispersion statistic for an attribute,
|
||||
* or produce an estimate if no info is available.
|
||||
*
|
||||
* min_estimate is the minimum estimate to return if insufficient data
|
||||
@ -180,11 +180,11 @@ get_atttypmod(Oid relid, AttrNumber attnum)
|
||||
* estimating the number of tuples produced by an equijoin.)
|
||||
*/
|
||||
double
|
||||
get_attdisbursion(Oid relid, AttrNumber attnum, double min_estimate)
|
||||
get_attdispersion(Oid relid, AttrNumber attnum, double min_estimate)
|
||||
{
|
||||
HeapTuple atp;
|
||||
Form_pg_attribute att_tup;
|
||||
double disbursion;
|
||||
double dispersion;
|
||||
int32 ntuples;
|
||||
|
||||
atp = SearchSysCacheTuple(ATTNUM,
|
||||
@ -194,18 +194,18 @@ get_attdisbursion(Oid relid, AttrNumber attnum, double min_estimate)
|
||||
if (!HeapTupleIsValid(atp))
|
||||
{
|
||||
/* this should not happen */
|
||||
elog(ERROR, "get_attdisbursion: no attribute tuple %u %d",
|
||||
elog(ERROR, "get_attdispersion: no attribute tuple %u %d",
|
||||
relid, attnum);
|
||||
return min_estimate;
|
||||
}
|
||||
att_tup = (Form_pg_attribute) GETSTRUCT(atp);
|
||||
|
||||
disbursion = att_tup->attdisbursion;
|
||||
if (disbursion > 0.0)
|
||||
return disbursion; /* we have a specific estimate from VACUUM */
|
||||
dispersion = att_tup->attdispersion;
|
||||
if (dispersion > 0.0)
|
||||
return dispersion; /* we have a specific estimate from VACUUM */
|
||||
|
||||
/*
|
||||
* Special-case boolean columns: the disbursion of a boolean is highly
|
||||
* Special-case boolean columns: the dispersion of a boolean is highly
|
||||
* unlikely to be anywhere near 1/numtuples, instead it's probably
|
||||
* more like 0.5.
|
||||
*
|
||||
@ -215,7 +215,7 @@ get_attdisbursion(Oid relid, AttrNumber attnum, double min_estimate)
|
||||
return 0.5;
|
||||
|
||||
/*
|
||||
* Disbursion is either 0 (no data available) or -1 (disbursion is
|
||||
* Dispersion is either 0 (no data available) or -1 (dispersion is
|
||||
* 1/numtuples). Either way, we need the relation size.
|
||||
*/
|
||||
|
||||
@ -225,7 +225,7 @@ get_attdisbursion(Oid relid, AttrNumber attnum, double min_estimate)
|
||||
if (!HeapTupleIsValid(atp))
|
||||
{
|
||||
/* this should not happen */
|
||||
elog(ERROR, "get_attdisbursion: no relation tuple %u", relid);
|
||||
elog(ERROR, "get_attdispersion: no relation tuple %u", relid);
|
||||
return min_estimate;
|
||||
}
|
||||
|
||||
@ -234,11 +234,11 @@ get_attdisbursion(Oid relid, AttrNumber attnum, double min_estimate)
|
||||
if (ntuples == 0)
|
||||
return min_estimate; /* no data available */
|
||||
|
||||
if (disbursion < 0.0) /* VACUUM thinks there are no duplicates */
|
||||
if (dispersion < 0.0) /* VACUUM thinks there are no duplicates */
|
||||
return 1.0 / (double) ntuples;
|
||||
|
||||
/*
|
||||
* VACUUM ANALYZE does not compute disbursion for system attributes,
|
||||
* VACUUM ANALYZE does not compute dispersion for system attributes,
|
||||
* but some of them can reasonably be assumed unique anyway.
|
||||
*/
|
||||
if (attnum == ObjectIdAttributeNumber ||
|
||||
@ -252,11 +252,11 @@ get_attdisbursion(Oid relid, AttrNumber attnum, double min_estimate)
|
||||
* = 1/numtuples. This may produce unreasonably small estimates for
|
||||
* large tables, so limit the estimate to no less than min_estimate.
|
||||
*/
|
||||
disbursion = 1.0 / (double) ntuples;
|
||||
if (disbursion < min_estimate)
|
||||
disbursion = min_estimate;
|
||||
dispersion = 1.0 / (double) ntuples;
|
||||
if (dispersion < min_estimate)
|
||||
dispersion = min_estimate;
|
||||
|
||||
return disbursion;
|
||||
return dispersion;
|
||||
}
|
||||
|
||||
/* ---------- INDEX CACHE ---------- */
|
||||
|
||||
@ -17,7 +17,7 @@ VACUUM \[ VERBOSE \] ANALYZE \[ table \[ (column \[, ...\] ) \] \]
|
||||
Prints a detailed vacuum activity report for each table.
|
||||
|
||||
" {} "ANALYZE" {italic} "
|
||||
Updates column statistics used by the optimizer to determine the most efficient way to execute a query. The statistics represent the disbursion of the data in each column. This information is valuable when several execution paths are possible.
|
||||
Updates column statistics used by the optimizer to determine the most efficient way to execute a query. The statistics represent the dispersion of the data in each column. This information is valuable when several execution paths are possible.
|
||||
|
||||
" {} "table" {italic} "
|
||||
The name of a specific table to vacuum. Defaults to all tables.
|
||||
|
||||
@ -8,7 +8,7 @@
|
||||
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
|
||||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* $Id: pg_attribute.h,v 1.63 2000/08/06 04:39:33 tgl Exp $
|
||||
* $Id: pg_attribute.h,v 1.64 2000/10/05 19:48:31 momjian Exp $
|
||||
*
|
||||
* NOTES
|
||||
* the genbki.sh script reads this file and generates .bki
|
||||
@ -54,15 +54,15 @@ CATALOG(pg_attribute) BOOTSTRAP
|
||||
* Postgres will fail.
|
||||
*/
|
||||
|
||||
float4 attdisbursion;
|
||||
float4 attdispersion;
|
||||
|
||||
/*
|
||||
* attdisbursion is the disbursion statistic of the column (0.0 to
|
||||
* attdispersion is the dispersion statistic of the column (0.0 to
|
||||
* 1.0), or zero if the statistic has not been calculated, or -1.0 if
|
||||
* VACUUM found that the column contains no duplicate entries (in
|
||||
* which case the disbursion should be taken as 1.0/numberOfRows for
|
||||
* which case the dispersion should be taken as 1.0/numberOfRows for
|
||||
* the current table size). The -1.0 hack is useful because the
|
||||
* number of rows may be updated more often than attdisbursion is. We
|
||||
* number of rows may be updated more often than attdispersion is. We
|
||||
* assume that the column will retain its no-duplicate-entry property.
|
||||
* (Perhaps this should be driven off the existence of a UNIQUE index
|
||||
* for the column, instead of being a statistical guess?)
|
||||
@ -178,7 +178,7 @@ typedef FormData_pg_attribute *Form_pg_attribute;
|
||||
#define Anum_pg_attribute_attrelid 1
|
||||
#define Anum_pg_attribute_attname 2
|
||||
#define Anum_pg_attribute_atttypid 3
|
||||
#define Anum_pg_attribute_attdisbursion 4
|
||||
#define Anum_pg_attribute_attdispersion 4
|
||||
#define Anum_pg_attribute_attlen 5
|
||||
#define Anum_pg_attribute_attnum 6
|
||||
#define Anum_pg_attribute_attnelems 7
|
||||
@ -381,7 +381,7 @@ DATA(insert OID = 0 ( 1261 tableoid 26 0 4 -7 0 -1 -1 t p f i f f));
|
||||
{ 1249, {"attrelid"}, 26, 0, 4, 1, 0, -1, -1, '\001', 'p', '\0', 'i', '\0', '\0' }, \
|
||||
{ 1249, {"attname"}, 19, 0, NAMEDATALEN, 2, 0, -1, -1, '\0', 'p', '\0', 'i', '\0', '\0' }, \
|
||||
{ 1249, {"atttypid"}, 26, 0, 4, 3, 0, -1, -1, '\001', 'p', '\0', 'i', '\0', '\0' }, \
|
||||
{ 1249, {"attdisbursion"}, 700, 0, 4, 4, 0, -1, -1, '\0', 'p', '\0', 'i', '\0', '\0' }, \
|
||||
{ 1249, {"attdispersion"}, 700, 0, 4, 4, 0, -1, -1, '\0', 'p', '\0', 'i', '\0', '\0' }, \
|
||||
{ 1249, {"attlen"}, 21, 0, 2, 5, 0, -1, -1, '\001', 'p', '\0', 's', '\0', '\0' }, \
|
||||
{ 1249, {"attnum"}, 21, 0, 2, 6, 0, -1, -1, '\001', 'p', '\0', 's', '\0', '\0' }, \
|
||||
{ 1249, {"attnelems"}, 23, 0, 4, 7, 0, -1, -1, '\001', 'p', '\0', 'i', '\0', '\0' }, \
|
||||
@ -397,7 +397,7 @@ DATA(insert OID = 0 ( 1261 tableoid 26 0 4 -7 0 -1 -1 t p f i f f));
|
||||
DATA(insert OID = 0 ( 1249 attrelid 26 0 4 1 0 -1 -1 t p f i f f));
|
||||
DATA(insert OID = 0 ( 1249 attname 19 0 NAMEDATALEN 2 0 -1 -1 f p f i f f));
|
||||
DATA(insert OID = 0 ( 1249 atttypid 26 0 4 3 0 -1 -1 t p f i f f));
|
||||
DATA(insert OID = 0 ( 1249 attdisbursion 700 0 4 4 0 -1 -1 f p f i f f));
|
||||
DATA(insert OID = 0 ( 1249 attdispersion 700 0 4 4 0 -1 -1 f p f i f f));
|
||||
DATA(insert OID = 0 ( 1249 attlen 21 0 2 5 0 -1 -1 t p f s f f));
|
||||
DATA(insert OID = 0 ( 1249 attnum 21 0 2 6 0 -1 -1 t p f s f f));
|
||||
DATA(insert OID = 0 ( 1249 attnelems 23 0 4 7 0 -1 -1 t p f i f f));
|
||||
|
||||
@ -7,7 +7,7 @@
|
||||
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
|
||||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* $Id: cost.h,v 1.34 2000/06/08 22:37:51 momjian Exp $
|
||||
* $Id: cost.h,v 1.35 2000/10/05 19:48:33 momjian Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
@ -63,7 +63,7 @@ extern void cost_mergejoin(Path *path, Path *outer_path, Path *inner_path,
|
||||
List *restrictlist,
|
||||
List *outersortkeys, List *innersortkeys);
|
||||
extern void cost_hashjoin(Path *path, Path *outer_path, Path *inner_path,
|
||||
List *restrictlist, Selectivity innerdisbursion);
|
||||
List *restrictlist, Selectivity innerdispersion);
|
||||
extern Cost cost_qual_eval(List *quals);
|
||||
extern void set_baserel_size_estimates(Query *root, RelOptInfo *rel);
|
||||
extern void set_joinrel_size_estimates(Query *root, RelOptInfo *rel,
|
||||
|
||||
@ -7,7 +7,7 @@
|
||||
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
|
||||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* $Id: pathnode.h,v 1.29 2000/09/29 18:21:40 tgl Exp $
|
||||
* $Id: pathnode.h,v 1.30 2000/10/05 19:48:33 momjian Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
@ -57,7 +57,7 @@ extern HashPath *create_hashjoin_path(RelOptInfo *joinrel,
|
||||
Path *inner_path,
|
||||
List *restrict_clauses,
|
||||
List *hashclauses,
|
||||
Selectivity innerdisbursion);
|
||||
Selectivity innerdispersion);
|
||||
|
||||
/*
|
||||
* prototypes for relnode.c
|
||||
|
||||
@ -6,7 +6,7 @@
|
||||
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
|
||||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* $Id: lsyscache.h,v 1.25 2000/08/13 02:50:31 tgl Exp $
|
||||
* $Id: lsyscache.h,v 1.26 2000/10/05 19:48:34 momjian Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
@ -21,7 +21,7 @@ extern AttrNumber get_attnum(Oid relid, char *attname);
|
||||
extern Oid get_atttype(Oid relid, AttrNumber attnum);
|
||||
extern bool get_attisset(Oid relid, char *attname);
|
||||
extern int32 get_atttypmod(Oid relid, AttrNumber attnum);
|
||||
extern double get_attdisbursion(Oid relid, AttrNumber attnum,
|
||||
extern double get_attdispersion(Oid relid, AttrNumber attnum,
|
||||
double min_estimate);
|
||||
extern RegProcedure get_opcode(Oid opno);
|
||||
extern char *get_opname(Oid opno);
|
||||
|
||||
Reference in New Issue
Block a user