Kees Jongenburger wrote:
> 
> First of all I don't unserstand why postgress is performing a sequence scan.
> but anyway. I turned inheritance off for the relation builders by
> using the "ONLY" keyword and this seams to greatly improve
> performance. the cost went from 498357 to 33949
> see
> http://carlit.mine.nu/~keesj/query.stuff.html
> 
> Is there any way we can change the generated sql to use the only
> keyword when performing queries over insrel?

There is none, in MMBase AFAIK. It would perhaps be a possible tweak to
let it add the ONLY keyword if it knows that the specified role is never
defined on the extended insrel tables. That seams feasible to implement
without very many troubles.

You get a similar situation as with the infamous 'OR' queries, which are
only performed if indeed both typerels exist.

On a sidenote. Did you check if the indices exist? Especially on the
'number's of the extended objects. (postgresql is a silly database, it
neeeds a seperate index for each extension, as you undoubtly know)



Michiel


-- 
Michiel Meeuwissen                  mihxil'
Mediacentrum 140 H'sum                [] ()
+31 (0)35 6772979         nl_NL eo_XX en_US



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