----------------------------------------------------------------------- WORKLOG TASK -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- TASK...........: Remove lazy subquery optimization CREATION DATE..: Mon, 06 Dec 2010, 12:55 SUPERVISOR.....: Igor IMPLEMENTOR....: Timour COPIES TO......: CATEGORY.......: Maria-BackLog TASK ID........: 168 (http://askmonty.org/worklog/?tid=168) VERSION........: Server-5.3 STATUS.........: Assigned PRIORITY.......: 60 WORKED HOURS...: 0 ESTIMATE.......: 16 (hours remain) ORIG. ESTIMATE.: 16 PROGRESS NOTES: DESCRIPTION: Remove all instances of lazy subquery optimization after MWL#89 is complete. Even after MWL#89, there are certain cases when subquery predicates are executed without prior optimization. This may result in bugs as well as high optimization/explain cost. In addition having a mixed subquery optimization approach results in a more complex architecture and higher degree of coupling between different query processing phases. The goal of this task is to investigate all remaining cases of lazy subquery optimization, and whenever possible change each such case to utilize the general approach of MWL#89. Currently known remaining cases: - sql_select.cc:remove_eq_cond calls cond->const_item() without checking if cond is expensive. ESTIMATED WORK TIME ESTIMATED COMPLETION DATE ----------------------------------------------------------------------- WorkLog (v4.0.0)