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author | Sergei Petrunia <psergey@askmonty.org> | 2015-03-27 23:44:06 +0300 |
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committer | Sergei Petrunia <psergey@askmonty.org> | 2015-03-27 23:44:06 +0300 |
commit | 9b8f86f8958116030de5a4e6ab75011cca251dfc (patch) | |
tree | ff440968f401ff811215cbbca94c257c36e58569 /sql/sql_select.h | |
parent | 47c26d5aeeae79276142746128c4b28f6693553d (diff) | |
download | mariadb-git-9b8f86f8958116030de5a4e6ab75011cca251dfc.tar.gz |
Better comments
Diffstat (limited to 'sql/sql_select.h')
-rw-r--r-- | sql/sql_select.h | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/sql/sql_select.h b/sql/sql_select.h index 0557e328ea0..94ca52471e0 100644 --- a/sql/sql_select.h +++ b/sql/sql_select.h @@ -1039,7 +1039,20 @@ public: table_map outer_join; /* Bitmap of tables used in the select list items */ table_map select_list_used_tables; - ha_rows send_records,found_records,examined_rows,row_limit, select_limit; + ha_rows send_records,found_records,examined_rows; + + /* + LIMIT for the JOIN operation. When not using aggregation or DISITNCT, this + is the same as select's LIMIT clause specifies. + Note that this doesn't take sql_calc_found_rows into account. + */ + ha_rows row_limit; + + /* + How many output rows should be produced after GROUP BY. + (if sql_calc_found_rows is used, LIMIT is ignored) + */ + ha_rows select_limit; /** Used to fetch no more than given amount of rows per one fetch operation of server side cursor. @@ -1048,8 +1061,10 @@ public: - fetch_limit= HA_POS_ERROR if there is no cursor. - when we open a cursor, we set fetch_limit to 0, - on each fetch iteration we add num_rows to fetch to fetch_limit + NOTE: currently always HA_POS_ERROR. */ ha_rows fetch_limit; + /* Finally picked QEP. This is result of join optimization */ POSITION *best_positions; |