hi at all, happy new year and thanks 3.0 RC sounds like a real good shit to me :-)
I found this some minutes ago because i can not sleep and so i started google something useful, is it safe for dbmail to set "transaction-isolation=READ-COMMITTED" or better leace the defaults to not hurt anything? http://www.mysqlperformanceblog.com/2007/11/01/innodb-performance-optimization-basics/ > Also check if your application can run in READ-COMMITED isolation mode – if it > does – set it to be default as transaction-isolation=READ-COMMITTED. This > option has some performance benefits, especially in locking in 5.0 and even > more to come with MySQL 5.1 and row level replication. http://dev.mysql.com/doc/refman/5.0/en/set-transaction.html#isolevel_read-committed A somewhat Oracle-like isolation level with respect to consistent (nonlocking) reads: Each consistent read, even within the same transaction, sets and reads its own fresh snapshot. See Section 13.2.8.2, “Consistent Nonlocking Reads”. For locking reads (SELECT with FOR UPDATE or LOCK IN SHARE MODE), InnoDB locks only index records, not the gaps before them, and thus permits the free insertion of new records next to locked records. For UPDATE and DELETE statements, locking depends on whether the statement uses a unique index with a unique search condition (such as WHERE id = 100), or a range-type search condition (such as WHERE id > 100). For a unique index with a unique search condition, InnoDB locks only the index record found, not the gap before it. For range-type searches, InnoDB locks the index range scanned, using gap locks or next-key (gap plus index-record) locks to block insertions by other sessions into the gaps covered by the range. This is necessary because “phantom rows” must be blocked for MySQL replication and recovery to work. -- Mit besten Grüßen, Reindl Harald the lounge interactive design GmbH A-1060 Vienna, Hofmühlgasse 17 CTO / software-development / cms-solutions p: +43 (1) 595 3999 33, m: +43 (676) 40 221 40 icq: 154546673, http://www.thelounge.net/ _______________________________________________ DBmail mailing list [email protected] http://mailman.fastxs.nl/cgi-bin/mailman/listinfo/dbmail
