Re: logical logs

In article <8727@emory.mathcs.emory.edu>, ilg@dasher.cc.bellcore.com (guthrie,ian) writes: > I am running informix-online 4.00.UH2 on a Pyramid MIS-12/05 (OSx 5.1a). > Part of the output from 'tbstat -l' is listed below: > address number flags uniqid begin size used %used > e0068944 1 U---C-L 5 100d64 250 66 26.40 > e0068960 2 F------ 0 100e5e 250 0 0.00 > e006897c 3 U-B---- 3 100f58 250 250 100.00 > e0068998 4 U-B---- 4 101052 250 250 100.00 > > My questions are: > > 1. What does the 'L' under the flags heading mean? I cannot find any > definition in the manuals. The last "checkpoint" is in that log. > 2. Why would online not release a log that has been backed-up (the > last two lines)? One reason that comes to mind is that you have a long-transaction that has spanned the first two logs and is now writing to the third. > 3. Is there a way to force online to release backed-up logs? > Not during a long-transaction. If a transaction spans logs, the logs can't be freed until the transaction is terminated. The reason for this is for a ROLLBACK WORK. If the logs are freed, how is Online going to rollback the transaction? Now this is neat... if you have a long transaction that enters the last log, Online will automatically rollback the work. What happens if you don't have enough space in the last log to rollback the transaction... you'd better have a real recent archive of your data. DAS -- David A. Snyder @ Snide Inc. - Folcroft, PA Current Release is db4glgen-3.4 UUCP: ..!uunet!das13!dave INTERNET: dave.snyder@snide.com