----------------------------------------------------------------------- WORKLOG TASK -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- TASK...........: Unused CREATION DATE..: Sun, 28 Feb 2010, 14:02 SUPERVISOR.....: Monty IMPLEMENTOR....: COPIES TO......: Igor, Psergey, Timour CATEGORY.......: Server-RawIdeaBin TASK ID........: 92 (http://askmonty.org/worklog/?tid=92) VERSION........: WorkLog-3.4 STATUS.........: Un-Assigned PRIORITY.......: 60 WORKED HOURS...: 0 ESTIMATE.......: 0 (hours remain) ORIG. ESTIMATE.: 0 PROGRESS NOTES: -=-=(Psergey - Sun, 28 Feb 2010, 14:57)=-=- High Level Description modified. --- /tmp/wklog.92.old.22267 2010-02-28 14:57:52.000000000 +0000 +++ /tmp/wklog.92.new.22267 2010-02-28 14:57:52.000000000 +0000 @@ -1 +1 @@ -We must fix known semi-join subquery bugs. + -=-=(Psergey - Sun, 28 Feb 2010, 14:57)=-=- Title modified. --- /tmp/wklog.92.old.22249 2010-02-28 14:57:41.000000000 +0000 +++ /tmp/wklog.92.new.22249 2010-02-28 14:57:41.000000000 +0000 @@ -1 +1 @@ -Subqueries: Inside-out execution for non-semijoin materialized subqueries that are AND-parts of the WHERE +Unused -=-=(Psergey - Sun, 28 Feb 2010, 14:51)=-=- High Level Description modified. --- /tmp/wklog.92.old.21961 2010-02-28 14:51:06.000000000 +0000 +++ /tmp/wklog.92.new.21961 2010-02-28 14:51:06.000000000 +0000 @@ -1,18 +1 @@ -Consider the following case: - -SELECT * FROM big_table -WHERE oe IN (SELECT ie FROM table_with_few_groups - WHERE ... - GROUP BY group_col) AND ... - -Here the best way to execute the query is: - - Materialize the subquery; - # now run the join: - for each record R1 in materialized table - for each record R2 in big_table such that oe=R1 - pass R2 to output - -Semi-join materialization supports such strategy with SJM-Scan strategy. This WL -entry is about adding support for such strategies for non-semijoin subqueries. - +We must fix known semi-join subquery bugs. -=-=(Psergey - Sun, 28 Feb 2010, 14:03)=-=- Observers changed: Psergey,Igor,Timour DESCRIPTION: ESTIMATED WORK TIME ESTIMATED COMPLETION DATE ----------------------------------------------------------------------- WorkLog (v3.5.9)