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Posted by Neil on 12/07/07 16:59
"Erland Sommarskog" <esquel@sommarskog.se> wrote in message
news:Xns99FEEDF6C864Yazorman@127.0.0.1...
> Neil (nospam@nospam.net) writes:
>> OK, that's fine. But my POV is that rebooting in general, and resetting
>> the system memory, is a good thing to do. I take it that you disagree?
>
> I do. Unless there is some known issues, there is rarely any reason to
> reboot SQL Server regularly. OK, so you have SQL 7, and this version is a
> bit old. Nevertheless, it has the same basic architecture as subsequent
> SQL Server versions. The predecessors 6.x were less stable. (In 6.0 there
> was a bug that compelled you to restart the bug about every 48th day.
> There was some counter somewhere that wrapped around after 49 days.)
>
> As for rebooting helping performance, it may be the other way round.
> When you reboot, the entire plan cache will be thrown away, and until
> the plan has built up, the server will spend more time compiling. But
> that's the only thing. Say that you have a table with date column,
> into which the current date is typically inserted, and queries against
> this table are typically for the recent days. If the query is a stored
> procedure or is parameterised, the plan will be built using that date.
> But if statistics are out of date, the estimates will be wrong, and you
> may get a bad plan. Had you never restarted the server, the old good
> plan would have remained in cache.
>
> But, OK, the reverse can happen: the old plan was bad, but statistics
> have been updated recently, so now you get a good plan.
>
> As for your problem the other day, you did not include any error message,
> but I would guess that it was a temporary network problem, and it would
> have gone away even if you had not restarted SQL Server.
>
> --
> Erland Sommarskog, SQL Server MVP, esquel@sommarskog.se
>
> Books Online for SQL Server 2005 at
> http://www.microsoft.com/technet/prodtechnol/sql/2005/downloads/books.mspx
> Books Online for SQL Server 2000 at
> http://www.microsoft.com/sql/prodinfo/previousversions/books.mspx
Thanks, Erland. Once again, your response is thorough and informative.
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