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| author | Vicențiu Ciorbaru <vicentiu@mariadb.org> | 2016-09-20 22:12:48 +0200 |
|---|---|---|
| committer | Vicențiu Ciorbaru <vicentiu@mariadb.org> | 2016-09-24 15:12:34 +0200 |
| commit | a2bafbabe2c1335bd411daf85dde8908e55dab62 (patch) | |
| tree | a7a08b9a3701d2f9aa23957a3bc5f7d58167b85d /sql/item_windowfunc.h | |
| parent | 15b8a772ccd39bad6d391f7e49733730e0eefae0 (diff) | |
| download | mariadb-git-a2bafbabe2c1335bd411daf85dde8908e55dab62.tar.gz | |
Make first_value and last_value computation efficient
With clever use of partition bounds, we only need to add one row to the
items at a time. This way we remove the need to "reset" the item and run
through the full partition again.
Diffstat (limited to 'sql/item_windowfunc.h')
| -rw-r--r-- | sql/item_windowfunc.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/sql/item_windowfunc.h b/sql/item_windowfunc.h index 6333207ebb6..ba5955084e2 100644 --- a/sql/item_windowfunc.h +++ b/sql/item_windowfunc.h @@ -657,6 +657,8 @@ public: case Item_sum::PERCENT_RANK_FUNC: case Item_sum::CUME_DIST_FUNC: case Item_sum::NTILE_FUNC: + case Item_sum::FIRST_VALUE_FUNC: + case Item_sum::LAST_VALUE_FUNC: return true; default: return false; |