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- Path: sparky!uunet!munnari.oz.au!spool.mu.edu!agate!ucbvax!mtxinu!sybase!houdini!jeffl
- From: jeffl@houdini.sybase.com (Jeff Lichtman)
- Newsgroups: comp.databases.sybase
- Subject: Re: Recovering from a log segment full condition
- Message-ID: <27585@sybase.sybase.com>
- Date: 4 Jan 93 20:20:12 GMT
- References: <1992Dec16.205611.19776@spectrum.xerox.com> <dave.724703604@rincon> <WFINNERT.92Dec21194611@larry.shearson.com>
- Sender: news@Sybase.COM
- Organization: Committee to Increase The Entropy
- Lines: 25
-
- In article <WFINNERT.92Dec21194611@larry.shearson.com>, wfinnert@larry.shearson.com (Warren Finnerty) writes:
- > Do any of you SYBASE types want to confess to what futz'ing around in model
- > goes on in conjunction with createing objects in tempdb. ( Not at startup )
- > --
- > warren finnerty | 388 Greenwich St.
-
- Usually, when you create an object, that object's ID is logged in the database
- that the object is created in. The server reads these object ids during
- recovery and remembers the last one used, so that we don't re-use an object id.
-
- This doesn't work for tempdb, because that database is re-created every time
- the server boots. We used to do the logging of object ids for tempdb in the
- model database, instead, which worked because tempdb is created from model.
- This created a bottleneck, however - when one user created a database, it would
- lock model and prevent other users from creating temporary tables. We changed
- the server so that it doesn't log object ids for tempdb at all - instead, it
- relies on the creation time of tempdb (which is the boot time of the server)
- to distinguish when an object id is in danger of re-use, so that it can
- recompile stored procedures when an object id in tempdb has been re-used.
-
- This change was implemented a long time ago. No current version of the
- SQL Server should log object ids from tempdb in model.
- ---
- Jeff Lichtman at Sybase
- {mtxinu,pacbell}!sybase!jeffl -or- jeffl@sybase.com
-