diff options
Diffstat (limited to 'sql/sql_select.h')
| -rw-r--r-- | sql/sql_select.h | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/sql/sql_select.h b/sql/sql_select.h index 8319969432c..1dba84f7822 100644 --- a/sql/sql_select.h +++ b/sql/sql_select.h @@ -190,8 +190,15 @@ typedef struct st_join_table { psergey2: for join tabs that are inside a bush: root of this bush. */ st_join_table *bush_root_tab; - bool last_leaf_in_bush; + /* TRUE <=> This join_tab is inside a join bush and is the last leaf tab here */ + bool last_leaf_in_bush; + + /* + ptr - this is a bush, and ptr points to description of child join_tab + range + NULL - this join tab has no bush children + */ JOIN_TAB_RANGE *bush_children; /* Special content for EXPLAIN 'Extra' column or NULL if none */ @@ -500,13 +507,13 @@ protected: context can be accessed. */ JOIN *join; -#if 0 - /* - Cardinality of the range of join tables whose fields can be put into the - cache. (A table from the range not necessarily contributes to the cache.) + /* + JOIN_TAB of the first table that can have it's fields in the join cache. + That is, tables in the [start_tab, tab) range can have their fields in the + join cache. + If a join tab in the range represents an SJM-nest, then all tables from the + nest can have their fields in the join cache, too. */ - uint tables; -#endif JOIN_TAB *start_tab; /* @@ -1505,7 +1512,6 @@ public: /* We also maintain a stack of join optimization states in * join->positions[] */ /******* Join optimization state members end *******/ - Next_select_func first_select; /* The cost of best complete join plan found so far during optimization, after optimization phase - cost of picked join order (not taking into @@ -1691,7 +1697,6 @@ public: rollup.state= ROLLUP::STATE_NONE; no_const_tables= FALSE; - first_select= sub_select; } int prepare(Item ***rref_pointer_array, TABLE_LIST *tables, uint wind_num, |