Simultaneous long sql operations

From: Joe Smith <nospam_at_nospam.com>
Date: Wed, 2 Mar 2005 10:34:35 +0100
Message-ID: <422588ab$0$11693$8fcfb975@news.wanadoo.fr>

Hi,

If I have several long sql operations, involving lots of I/O, what is the correct reasoning?:
1 - Execute them one by one, so the disk doesn't have to go back and forth for the different requests.
2 - Execute them in parallel, so oracle can more efficiently 'program' the reads and writes to perform.

I guess 1 reduces the response time of each individual request, and 2 reduces the total time.

If 2 is correct, I was wondering... What's the point of individual execution plans? I guess the plans are changed 'on the fly', or something like that, depending on the requests arriving.

Thanks in advance. Received on Wed Mar 02 2005 - 03:34:35 CST