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Relax ordering-related hardcoded btree requirements in planning

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There were several places in ordering-related planning where a
requirement for btree was hardcoded but an amcanorder index could
suffice.  This fixes that.  We just need to do the necessary mapping
between strategy numbers and compare types and adjust some related
APIs so that this works independent of btree strategy numbers.  For
instance, non-btree amcanorder indexes can now be used to support
sorting and merge joins.  Also, predtest.c works independent of btree
strategy numbers now.

To avoid performance regressions, some details on btree and other
built-in index types are still hardcoded as shortcuts, but other index
types now have access to the same features by providing the required
flags and callbacks.

Author: Mark Dilger <mark.dilger@enterprisedb.com>
Co-authored-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://www.postgresql.org/message-id/flat/E72EAA49-354D-4C2E-8EB9-255197F55330@enterprisedb.com
This commit is contained in:
Peter Eisentraut
2025-04-06 14:43:51 +02:00
parent 3a1a7c5a70
commit a8025f5448
16 changed files with 298 additions and 226 deletions
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62
src/backend/utils/adt/selfuncs.c
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@@ -2947,7 +2947,7 @@ scalargejoinsel(PG_FUNCTION_ARGS)
* first join pair is found, which will affect the join's startup time.
*
* clause should be a clause already known to be mergejoinable. opfamily,
* strategy, and nulls_first specify the sort ordering being used.
* cmptype, and nulls_first specify the sort ordering being used.
*
* The outputs are:
* *leftstart is set to the fraction of the left-hand variable expected
@@ -2958,7 +2958,7 @@ scalargejoinsel(PG_FUNCTION_ARGS)
*/
void
mergejoinscansel(PlannerInfo *root, Node *clause,
Oid opfamily, int strategy, bool nulls_first,
Oid opfamily, CompareType cmptype, bool nulls_first,
Selectivity *leftstart, Selectivity *leftend,
Selectivity *rightstart, Selectivity *rightend)
{
@@ -2966,6 +2966,7 @@ mergejoinscansel(PlannerInfo *root, Node *clause,
*right;
VariableStatData leftvar,
rightvar;
Oid opmethod;
int op_strategy;
Oid op_lefttype;
Oid op_righttype;
@@ -2979,6 +2980,10 @@ mergejoinscansel(PlannerInfo *root, Node *clause,
leop,
revltop,
revleop;
StrategyNumber ltstrat,
lestrat,
gtstrat,
gestrat;
bool isgt;
Datum leftmin,
leftmax,
@@ -3005,12 +3010,14 @@ mergejoinscansel(PlannerInfo *root, Node *clause,
examine_variable(root, left, 0, &leftvar);
examine_variable(root, right, 0, &rightvar);
opmethod = get_opfamily_method(opfamily);
/* Extract the operator's declared left/right datatypes */
get_op_opfamily_properties(opno, opfamily, false,
&op_strategy,
&op_lefttype,
&op_righttype);
Assert(op_strategy == BTEqualStrategyNumber);
Assert(IndexAmTranslateStrategy(op_strategy, opmethod, opfamily, true) == COMPARE_EQ);
/*
* Look up the various operators we need. If we don't find them all, it
@@ -3019,19 +3026,21 @@ mergejoinscansel(PlannerInfo *root, Node *clause,
* Note: we expect that pg_statistic histograms will be sorted by the '<'
* operator, regardless of which sort direction we are considering.
*/
switch (strategy)
switch (cmptype)
{
case BTLessStrategyNumber:
case COMPARE_LT:
isgt = false;
ltstrat = IndexAmTranslateCompareType(COMPARE_LT, opmethod, opfamily, true);
lestrat = IndexAmTranslateCompareType(COMPARE_LE, opmethod, opfamily, true);
if (op_lefttype == op_righttype)
{
/* easy case */
ltop = get_opfamily_member(opfamily,
op_lefttype, op_righttype,
BTLessStrategyNumber);
ltstrat);
leop = get_opfamily_member(opfamily,
op_lefttype, op_righttype,
BTLessEqualStrategyNumber);
lestrat);
lsortop = ltop;
rsortop = ltop;
lstatop = lsortop;
@@ -3043,43 +3052,46 @@ mergejoinscansel(PlannerInfo *root, Node *clause,
{
ltop = get_opfamily_member(opfamily,
op_lefttype, op_righttype,
BTLessStrategyNumber);
ltstrat);
leop = get_opfamily_member(opfamily,
op_lefttype, op_righttype,
BTLessEqualStrategyNumber);
lestrat);
lsortop = get_opfamily_member(opfamily,
op_lefttype, op_lefttype,
BTLessStrategyNumber);
ltstrat);
rsortop = get_opfamily_member(opfamily,
op_righttype, op_righttype,
BTLessStrategyNumber);
ltstrat);
lstatop = lsortop;
rstatop = rsortop;
revltop = get_opfamily_member(opfamily,
op_righttype, op_lefttype,
BTLessStrategyNumber);
ltstrat);
revleop = get_opfamily_member(opfamily,
op_righttype, op_lefttype,
BTLessEqualStrategyNumber);
lestrat);
}
break;
case BTGreaterStrategyNumber:
case COMPARE_GT:
/* descending-order case */
isgt = true;
ltstrat = IndexAmTranslateCompareType(COMPARE_LT, opmethod, opfamily, true);
gtstrat = IndexAmTranslateCompareType(COMPARE_GT, opmethod, opfamily, true);
gestrat = IndexAmTranslateCompareType(COMPARE_GE, opmethod, opfamily, true);
if (op_lefttype == op_righttype)
{
/* easy case */
ltop = get_opfamily_member(opfamily,
op_lefttype, op_righttype,
BTGreaterStrategyNumber);
gtstrat);
leop = get_opfamily_member(opfamily,
op_lefttype, op_righttype,
BTGreaterEqualStrategyNumber);
gestrat);
lsortop = ltop;
rsortop = ltop;
lstatop = get_opfamily_member(opfamily,
op_lefttype, op_lefttype,
BTLessStrategyNumber);
ltstrat);
rstatop = lstatop;
revltop = ltop;
revleop = leop;
@@ -3088,28 +3100,28 @@ mergejoinscansel(PlannerInfo *root, Node *clause,
{
ltop = get_opfamily_member(opfamily,
op_lefttype, op_righttype,
BTGreaterStrategyNumber);
gtstrat);
leop = get_opfamily_member(opfamily,
op_lefttype, op_righttype,
BTGreaterEqualStrategyNumber);
gestrat);
lsortop = get_opfamily_member(opfamily,
op_lefttype, op_lefttype,
BTGreaterStrategyNumber);
gtstrat);
rsortop = get_opfamily_member(opfamily,
op_righttype, op_righttype,
BTGreaterStrategyNumber);
gtstrat);
lstatop = get_opfamily_member(opfamily,
op_lefttype, op_lefttype,
BTLessStrategyNumber);
ltstrat);
rstatop = get_opfamily_member(opfamily,
op_righttype, op_righttype,
BTLessStrategyNumber);
ltstrat);
revltop = get_opfamily_member(opfamily,
op_righttype, op_lefttype,
BTGreaterStrategyNumber);
gtstrat);
revleop = get_opfamily_member(opfamily,
op_righttype, op_lefttype,
BTGreaterEqualStrategyNumber);
gestrat);
}
break;
default: