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Do not use inputs which values are known constants in ActionsDAG.

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This commit is contained in:
Nikolai Kochetov 2021-02-02 14:58:35 +03:00
parent fd5adf1ff6
commit 998aed3029
1 changed files with 10 additions and 0 deletions
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10
src/Interpreters/ActionsDAG.cpp
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@ -39,7 +39,17 @@ ActionsDAG::ActionsDAG(const ColumnsWithTypeAndName & inputs_)
for (const auto & input : inputs_)
{
if (input.column && isColumnConst(*input.column))
{
addInput(input, true);
/// Here we also add column.
/// It will allow to remove input which is actually constant (after projection).
/// Also, some transforms from query pipeline may randomly materialize constants,
/// without any respect to header structure. So, it is a way to drop materialized column and use
/// constant value from header.
/// We cannot remove such input right now cause inputs positions are important in some cases.
addColumn(input, true);
}
else
addInput(input.name, input.type, true);
}