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Code Issues

Fixed CORE-1550: Unnecessary index scan happens when the same index is mapped to both WHERE and ORDER BY clauses.

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This commit is contained in:
dimitr 2010-03-11 10:03:32 +00:00
parent ad5763f303
commit c65e55c9e6
2 changed files with 12 additions and 3 deletions
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14
src/jrd/Optimizer.cpp
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@ -816,6 +816,7 @@ IndexScratch::IndexScratch(MemoryPool& p, thread_db* tdbb, index_desc* ix,
selectivity = MAXIMUM_SELECTIVITY;
candidate = false;
scopeCandidate = false;
utilized = false;
lowerCount = 0;
upperCount = 0;
nonFullMatchedSegments = 0;
@ -842,7 +843,8 @@ IndexScratch::IndexScratch(MemoryPool& p, thread_db* tdbb, index_desc* ix,
// Compound indexes are generally less compressed.
factor = 0.7;
}
Database* dbb = tdbb->getDatabase();
const Database* const dbb = tdbb->getDatabase();
cardinality = (csb_tail->csb_cardinality * (2 + (length * factor))) / (dbb->dbb_page_size - BTR_SIZE);
cardinality = MAX(cardinality, MINIMUM_CARDINALITY);
}
@ -863,6 +865,7 @@ IndexScratch::IndexScratch(MemoryPool& p, const IndexScratch& scratch) :
cardinality = scratch.cardinality;
candidate = scratch.candidate;
scopeCandidate = scratch.scopeCandidate;
utilized = scratch.utilized;
lowerCount = scratch.lowerCount;
upperCount = scratch.upperCount;
nonFullMatchedSegments = scratch.nonFullMatchedSegments;
@ -1464,6 +1467,7 @@ IndexTableScan* OptimizerRetrieval::generateNavigation()
*sort = NULL;
idx->idx_runtime_flags |= idx_navigate;
indexScratches[i].utilized = true;
jrd_nod* const index_node = makeIndexScanNode(&indexScratches[i]);
const USHORT key_length = ROUNDUP(BTR_key_length(tdbb, relation, idx), sizeof(SLONG));
return FB_NEW(*tdbb->getDefaultPool())
@ -1530,6 +1534,7 @@ void OptimizerRetrieval::getInversionCandidates(InversionCandidateList* inversio
{
IndexScratch& scratch = (*fromIndexScratches)[i];
scratch.scopeCandidate = false;
scratch.utilized = false;
scratch.lowerCount = 0;
scratch.upperCount = 0;
scratch.nonFullMatchedSegments = MAX_INDEX_SEGMENTS + 1;
@ -1886,7 +1891,8 @@ jrd_nod* OptimizerRetrieval::makeIndexScanNode(IndexScratch* indexScratch) const
// already at index scan. But this rule doesn't apply to nod_equiv
// which requires NULLs to be found in the index.
// A second exception is when this index is used for navigation.
if (ignoreNullsOnScan && !(idx->idx_runtime_flags & idx_navigate)) {
if (ignoreNullsOnScan && !(idx->idx_runtime_flags & idx_navigate))
{
retrieval->irb_generic |= irb_ignore_null_value_key;
}
@ -1980,7 +1986,9 @@ InversionCandidate* OptimizerRetrieval::makeInversion(InversionCandidateList* in
inversion[i]->used = false;
if (inversion[i]->scratch)
{
if (inversion[i]->scratch->idx->idx_runtime_flags & idx_plan_dont_use) {
if (inversion[i]->scratch->utilized ||
inversion[i]->scratch->idx->idx_runtime_flags & idx_plan_dont_use)
{
inversion[i]->used = true;
}
}

1
src/jrd/Optimizer.h
View File

@ -137,6 +137,7 @@ public:
double selectivity; // calculated selectivity for this index
bool candidate; // used when deciding which indices to use
bool scopeCandidate; // used when making inversion based on scope
bool utilized; // index is already utilized by some scan
int lowerCount; //
int upperCount; //
int nonFullMatchedSegments; //