thevar1able/ClickHouse
1
0
Fork 0
mirror of https://github.com/ClickHouse/ClickHouse.git synced 2024-09-22 09:40:49 +00:00
Code Issues Packages Projects Releases Wiki Activity

clickhouse: slightly faster logical functions on small blocks. [#METR-9599]

Browse Source
This commit is contained in:
Michael Kolupaev 2014-02-20 11:55:41 +04:00
parent 8351446de2
commit 9a9eca1721
1 changed files with 6 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
dbms/include/DB/Functions/FunctionsLogical.h
View File

@ -292,7 +292,12 @@ public:
/// Эффективно скомбинируем все столбцы правильного типа.
while (uint8_in.size() > 1)
{
AssociativeOperationImpl<Impl<UInt8>, 6>::execute(uint8_in, vec_res);
/// При большом размере блока объединять по 6 толбцов за проход быстрее всего.
/// При маленьком - чем больше, тем быстрее.
if (n > 65536)
AssociativeOperationImpl<Impl<UInt8>, 6>::execute(uint8_in, vec_res);
else
AssociativeOperationImpl<Impl<UInt8>, 10>::execute(uint8_in, vec_res);
uint8_in.push_back(col_res);
}