Hi Jerry, all!
Jerry Schwartz wrote: >> [[...]] >> >> Maybe: >> >> WHERE coalesce(x, 17) = 17 >> >> > [JS] Interesting suggestion, but > > us-gii >select benchmark(10000000,(7=7 or null is null)); > [[...]] > 1 row in set (0.34 sec) > > us-gii >select benchmark(100000000,coalesce(null,7)); > [[...]] > 1 row in set (2.61 sec) > > It looks like COALESCE() is slower. Of course this isn't anything like a real > test. [[...]] Both your statements use constants only, so they can be evaluated during statement analysis and need not access any data. I don't think the time relation you get here can be applied to a statement really getting column values from a table and using them in a predicate. Regards, Jörg -- Joerg Bruehe, MySQL Build Team, joerg.bru...@sun.com Sun Microsystems GmbH, Komturstraße 18a, D-12099 Berlin Geschaeftsfuehrer: Thomas Schroeder, Wolfgang Engels Vorsitzender des Aufsichtsrates: Martin Haering Muenchen: HRB161028 -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
