Re: Arcane bits

Path: emory!wupost!cs.utexas.edu!asuvax!anasaz!qip!briand From: briand@anasaz (Brian Douglass) Newsgroups: comp.databases.informix Keywords: FAQ features arcane Message-ID: <1992Jan19.032315.5435@anasaz> Date: 19 Jan 92 03:23:15 GMT References: <1992Jan14.201257.14449@cpqhou.uucp> <1992Jan15.201722.10567@anasaz> <1992Jan16.120825.24238@cis.ohio-state.edu> Organization: Anasazi, Inc. Phoenix, Az Speaking of arcane bits, for all Informix 4.1 users out there, be very careful about exceeding the LOCKS setting in tbconfig. All hell breaks loose when you. Was working on a production system with about 40,000 rows, and three indexes. Ran the little statement: update foo set print_date = today where print_date = 0 and ctype = "N"; There were maybe 10,000 rows that this would affect. The system put one lock on each row, plus 3 more locks for the indexes, for a total of about 40,000. LOCKS was only set to 30,000. Aye, yi, yi! What a mess! When finally had to drop back a day in backups to restore from. Utilities like tbcheck didn't seem to affect the necessary repairs. Through hindsight, it's obvious I should have started a transaction, put an exclusive lock on the table, and then did my update. But hey, this was a production system and there was a process out there that could have been adding rows while I worked. Moral: Bump up your LOCKS setting to the largest practical number you can. (see your local dealer for further information.) -- Brian Douglass briand%anasaz.UUCP@asuvax.eas.asu.edu 602-870-3330 X657