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- Committer: Prafulla Tekawade
- Date: 2010-07-18 03:36:32 UTC
- mto: (1662.1.4 rollup)
- mto: This revision was merged to the branch mainline in revision 1664.
- Revision ID: prafulla_t@users.sourceforge.net-20100718033632-p7q6qtgliqbhe38p
Fix for Bug 592444
There were two problems:
o. In greedy_search optimizer method, best_extension_by_limited search
maintains join embedding(nestedness) of tables added so far, so that
correct(valid) join order is selected
These are requirements from nested outer join executioner.
The problem was, embedding_map was not correctly updated when a table
is added to optimal plan outside best_extension_by_limited search,
by greedy_search method. We need to update join->cur_embedding_map
correctly here so that execution plan for other tables get
generated.
Invoked checked_interleaving_with_nj from greedy_search on the
best_table selected. Fixed its prototype to take only one JoinTab
This is same as mysql 5.1 source tree.
o. The other problem was, join->cur_embedding_map was not restored correctly
when a table is added to the optimal plan to reflect the current embedding
map.
Taken good documented method restore_prev_nj_state which restores
cur_embedding_map from mysql 5.1 source tree and modified it for drizzled
code.
There were two problems:
o. In greedy_search optimizer method, best_extension_by_limited search
maintains join embedding(nestedness) of tables added so far, so that
correct(valid) join order is selected
These are requirements from nested outer join executioner.
The problem was, embedding_map was not correctly updated when a table
is added to optimal plan outside best_extension_by_limited search,
by greedy_search method. We need to update join->cur_embedding_map
correctly here so that execution plan for other tables get
generated.
Invoked checked_interleaving_with_nj from greedy_search on the
best_table selected. Fixed its prototype to take only one JoinTab
This is same as mysql 5.1 source tree.
o. The other problem was, join->cur_embedding_map was not restored correctly
when a table is added to the optimal plan to reflect the current embedding
map.
Taken good documented method restore_prev_nj_state which restores
cur_embedding_map from mysql 5.1 source tree and modified it for drizzled
code.
added
removed
drizzled/sql_select.cc
