Re: OR and sequence of results

It is not a feature, it is a side effect of whichever execution path Oracle
chooses to take. It is highly dependent on versions, choice of optimiser, existence of indexes and size of data.

Don't depend on it.

--

Jonathan Lewis
Yet another Oracle-related web site:  http://www.jlcomp.demon.co.uk

rjones_at_cincom.com wrote in message <8kfbjl$kr5$1_at_nnrp1.deja.com>...


>I've recently noticed that in the absence of any other sequencing, the

>position of OR statements will influence the sequence of results for a

>simple query. Take a single column table X with values 'A', 'B'

>and 'C', the query...

>

>select rownum, col from x where col = 'A' or col = 'B' or col = 'C'

>

>...will give:

>

>   ROWNUM COL

>--------- ---

>        1  C

>        2  B

>        3  A

>

>But...

>

>select rownum, col from x where col = 'C' or col = 'B' or col = 'A'

>

>...will give:

>

>   ROWNUM COL

>--------- ---

>        1  A

>        2  B

>        3  C

>

>This doesn't seem to be documented anywhere. It's a potentially useful

>feature, if indeed it is a feature is not going to be 'fixed' in the

>next release.

>

>Any thoughts???

>

>Rod

>

>

>Sent via Deja.com http://www.deja.com/

>Before you buy.