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Merge pull request #37666 from CurtizJ/optimize-coalesce

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Optimize function `COALESCE` with two arguments
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Anton Popov 2022-05-31 23:48:13 +02:00 committed by GitHub
commit 20e319d67a
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2 changed files with 13 additions and 2 deletions
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12
src/Functions/coalesce.cpp
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@ -112,7 +112,6 @@ public:
auto is_not_null = FunctionFactory::instance().get("isNotNull", context);
auto assume_not_null = FunctionFactory::instance().get("assumeNotNull", context);
auto multi_if = FunctionFactory::instance().get("multiIf", context);
ColumnsWithTypeAndName multi_if_args;
ColumnsWithTypeAndName tmp_args(1);
@ -144,7 +143,16 @@ public:
if (multi_if_args.size() == 1)
return multi_if_args.front().column;
ColumnPtr res = multi_if->build(multi_if_args)->execute(multi_if_args, result_type, input_rows_count);
/// If there was only two arguments (3 arguments passed to multiIf)
/// use function "if" instead, because it's implemented more efficient.
/// TODO: make "multiIf" the same efficient.
FunctionOverloadResolverPtr if_function;
if (multi_if_args.size() == 3)
if_function = FunctionFactory::instance().get("if", context);
else
if_function = FunctionFactory::instance().get("multiIf", context);
ColumnPtr res = if_function->build(multi_if_args)->execute(multi_if_args, result_type, input_rows_count);
/// if last argument is not nullable, result should be also not nullable
if (!multi_if_args.back().column->isNullable() && res->isNullable())

3
tests/performance/conditional.xml
View File

@ -8,4 +8,7 @@
<query>SELECT count() FROM zeros(10000000) WHERE NOT ignore(multiIf(rand() % 2, toDateTime(rand()), toDate(rand())))</query>
<query>SELECT count() FROM zeros(10000000) WHERE NOT ignore(if(rand() % 2, [toDateTime(rand())], [toDate(rand())]))</query>
<query>SELECT count() FROM zeros(10000000) WHERE NOT ignore(multiIf(rand() % 2, [toDateTime(rand())], [toDate(rand())]))</query>
<query>SELECT count() FROM numbers(50000000) WHERE NOT ignore(COALESCE(toNullable(number), 0))</query>
<query>SELECT count() FROM numbers(10000000) WHERE NOT ignore(multiIf(number % 7 = 0, 1, number % 3 = 0, 2, number % 5 = 0, 3, number % 11 = 0, 4, 5))</query>
</test>