https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=42585
--- Comment #10 from Kyle M Hall (khall) <[email protected]> --- Created attachment 203798 --> https://bugs.koha-community.org/bugzilla3/attachment.cgi?id=203798&action=edit Bug 42585: Add EXPLAIN-based analyzers This patch adds five checks that read the EXPLAIN plan instead of the SQL text: * large_temp_table_risk, a temp table bigger than the server's in memory cap, so it spills to disk * uses_join_buffer, the planner picked a Block Nested Loop because there's no index on the join column * dependent_subquery, the planner expects to run the subquery again for every outer row * full_table_scan, an access type of ALL on a table that isn't small * low_filter_efficiency, a full scan that keeps less than 10% of the rows it reads Scans of small lookup tables like branches and authorised_values are suppressed. Test Plan: 1) Apply this patch 2) prove t/Koha/Reports/Analyzer/Check/Explain/ 3) Analyze a report with the SQL "SELECT b.*, ( SELECT COUNT(*) FROM issues i WHERE i.borrowernumber = b.borrowernumber ) FROM borrowers b" 4) Note the dependent_subquery finding! 5) Analyze a report with the SQL "SELECT borrowernumber FROM borrowers WHERE borrowernumber = 1" 6) Note there are no EXPLAIN findings at all! -- You are receiving this mail because: You are watching all bug changes. _______________________________________________ Koha-bugs mailing list -- [email protected] To unsubscribe send an email to [email protected] website : http://www.koha-community.org/ git : http://git.koha-community.org/ bugs : http://bugs.koha-community.org/
