hcq/MaxScale
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MXS-1359 Turn recursion into iteration

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In case of very large compound selects or an INSERT with many
values, qc_sqlite could run out of stack space. To deal with
that, the critical recursion is turned into an iteration.
This commit is contained in:
Johan Wikman 2017-08-14 13:29:19 +03:00
parent 4798810f76
commit c662bea983
1 changed files with 23 additions and 5 deletions
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28
query_classifier/qc_sqlite/qc_sqlite.cc
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@ -1084,10 +1084,17 @@ public:
}
}
enum compound_approach_t
{
ANALYZE_COMPOUND_SELECTS,
IGNORE_COMPOUND_SELECTS
};
void update_field_infos_from_select(QcAliases& aliases,
const Select* pSelect,
uint32_t usage,
const ExprList* pExclude)
const ExprList* pExclude,
compound_approach_t compound_approach = ANALYZE_COMPOUND_SELECTS)
{
if (pSelect->pSrc)
{
@ -1156,20 +1163,31 @@ public:
update_field_infos_from_with(&aliases, pSelect->pWith);
}
if (((pSelect->op == TK_UNION) || (pSelect->op == TK_ALL)) && pSelect->pPrior)
if (compound_approach == ANALYZE_COMPOUND_SELECTS)
{
update_field_infos_from_subselect(&aliases, pSelect->pPrior, usage, pExclude);
if (((pSelect->op == TK_UNION) || (pSelect->op == TK_ALL)) && pSelect->pPrior)
{
const Select* pPrior = pSelect->pPrior;
while (pPrior)
{
update_field_infos_from_subselect(&aliases, pPrior, usage, pExclude,
IGNORE_COMPOUND_SELECTS);
pPrior = pPrior->pPrior;
}
}
}
}
void update_field_infos_from_subselect(QcAliases* pAliases,
const Select* pSelect,
uint32_t usage,
const ExprList* pExclude)
const ExprList* pExclude,
compound_approach_t compound_approach = ANALYZE_COMPOUND_SELECTS)
{
QcAliases aliases(*pAliases);
update_field_infos_from_select(aliases, pSelect, usage, pExclude);
update_field_infos_from_select(aliases, pSelect, usage, pExclude, compound_approach);
}
void update_field_infos_from_with(QcAliases* pAliases, const With* pWith)