Re: Optimisation of a sql query

From: joel garry <joel-garry_at_home.com>
Date: 19 Jul 2006 14:17:44 -0700
Message-ID: <1153343864.523165.191870@m79g2000cwm.googlegroups.com>

Abhijat wrote:

> A quick note to Sybrand and David: I guess I could not make myself very
> clear in my last mail. I am not working on Oracle tables. I am working
> in SAS and working with SAS datasets. Hence, the version still remains
> to be SAS 9.1. Please help with regards to this.

This is an Oracle group. It would be silly to ask non-Oracle questions here. If you are getting the data from an Oracle database, please tell us the version.

In Oracle, only very old software versions (or very obscure situations) care what order the SQL is in. Oracle will use statistics on the tables to find the best access method for the data. That is the plan everyone is talking about - before it even runs, you can get a pretty good idea what the plan will be, although when the query actually runs Oracle may indeed use a different plan. Again, we can help you figure out what is actually going on if you are getting the data from an Oracle database. If you expect different databases to execute the same SQL the same way, you are in for a rude awakening.

And Mladen is wrong about one thing, portable SQL will not suck equally on every database. It will likely suck extremely badly on some databases, but only suck very badly on others.

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Received on Wed Jul 19 2006 - 16:17:44 CDT