Oracle vs. SQLServer

Hi Harry,

Sorry to hear you're going to be using MSSQL. We're switching to Oracle, and off the top of my head my tips are:

1. It tends to corrupt it's own meta data if you do not have more CPU than you need. This is a timing bug, which is especially bad with big tables, and you eventually get errors where a page belonging to one table/index has been assigned to another table/index and you have to kick the users off and rebuild the entire database.
2. The optimiser is appalling - a query that has been working fine for months will spontaniously become hideously slow. The answer is to create temporary tables on the fly and break up the queries, effectively doing the optimisation manually. Keep queries down to only a few tables at a time. Large tables (eg we have 85+million rows) often *need* to have the appropriate data extracted into temp tables before joining.
3. If you have an SMP machine, always leave at least one processor free for NT, and the rest for SQL. This means don't bother buying a dual processor machine because you can only use one for MSSQL. Also, don't enable the priority boost. These are all recommendations from MS tech support after discovering the problems in (1).
4. Dumps are not compatable between processor types (ie Intel/Alpha).

John

> -----Original Message-----
> From: Harry Boswell [SMTP:hboswell_at_mdrs.state.ms.us]
> Posted At: Tuesday, May 19, 1998 10:25 PM
> Posted To: misc
> Conversation: Oracle vs. SQLServer
> Subject: Oracle vs. SQLServer
>
> I have worked with Oracle since 1985, except for the past 2 years.
> Now, I've got to set up a SQLServer database. There's no choice in
> the matter, the application we have committed to is based on
> SQLServer, and the vendor won't support an Oracle port. So -
> what are the major differences, especially between Oracle 7
> and SQLServer? From a DBA standpoint, what do I most
> need to be aware of?
>
> Thanks,
> Harry
Received on Wed May 20 1998 - 13:34:16 CDT