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This commit is contained in:
Alexey Milovidov 2015-06-05 20:41:51 +03:00
commit f78e0925da
1 changed files with 44 additions and 18 deletions
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42
dbms/include/DB/Storages/MergeTree/MergeTreeWhereOptimizer.h
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@ -9,12 +9,14 @@
#include <DB/Parsers/ASTSubquery.h> #include <DB/Parsers/ASTSubquery.h>
#include <DB/Parsers/formatAST.h> #include <DB/Parsers/formatAST.h>
#include <DB/Common/escapeForFileName.h> #include <DB/Common/escapeForFileName.h>
#include <statdaemons/ext/scope_guard.hpp>
#include <memory> #include <memory>
#include <unordered_map> #include <unordered_map>
#include <map> #include <map>
#include <limits> #include <limits>
#include <cstddef> #include <cstddef>
namespace DB namespace DB
{ {
@ -96,12 +98,6 @@ private:
{ {
const auto condition = conditions[idx].get(); const auto condition = conditions[idx].get();
IdentifierNameSet identifiers{};
collectIdentifiersNoSubqueries(condition, identifiers);
/// do not take into consideration the conditions consisting only of primary key columns
if (hasNonPrimaryKeyColumns(identifiers) && isSubsetOfTableColumns(identifiers))
{
/// linearize sub-conjunctions /// linearize sub-conjunctions
if (const auto function = typeid_cast<ASTFunction *>(condition)) if (const auto function = typeid_cast<ASTFunction *>(condition))
{ {
@ -118,6 +114,17 @@ private:
} }
} }
SCOPE_EXIT(++idx);
if (hasRestrictedFunctions(condition))
continue;
IdentifierNameSet identifiers{};
collectIdentifiersNoSubqueries(condition, identifiers);
/// do not take into consideration the conditions consisting only of primary key columns
if (hasNonPrimaryKeyColumns(identifiers) && isSubsetOfTableColumns(identifiers))
{
/// calculate size of columns involved in condition /// calculate size of columns involved in condition
const auto cond_columns_size = getIdentifiersColumnSize(identifiers); const auto cond_columns_size = getIdentifiersColumnSize(identifiers);
@ -129,8 +136,6 @@ private:
good_or_viable_condition.second = cond_columns_size; good_or_viable_condition.second = cond_columns_size;
} }
} }
++idx;
} }
const auto move_condition_to_prewhere = [&] (const std::size_t idx) { const auto move_condition_to_prewhere = [&] (const std::size_t idx) {
@ -180,6 +185,10 @@ private:
{ {
auto & condition = select.where_expression; auto & condition = select.where_expression;
/// do not optimize restricted expressions
if (hasRestrictedFunctions(select.where_expression.get()))
return;
IdentifierNameSet identifiers{}; IdentifierNameSet identifiers{};
collectIdentifiersNoSubqueries(condition, identifiers); collectIdentifiersNoSubqueries(condition, identifiers);
@ -300,6 +309,23 @@ private:
return true; return true;
} }
/// we assume all AS aliases have been expanded previously
static bool hasRestrictedFunctions(const IAST * ptr)
{
if (const auto function_ptr = typeid_cast<const ASTFunction *>(ptr))
{
/// disallow arrayJoin expressions to be moved to PREWHERE for now
if ("arrayJoin" == function_ptr->name)
return true;
}
for (const auto & child : ptr->children)
if (hasRestrictedFunctions(child.get()))
return true;
return false;
}
string_set_t primary_key_columns{}; string_set_t primary_key_columns{};
string_set_t table_columns{}; string_set_t table_columns{};
Logger * log; Logger * log;