Re: constraint with reference to the same table

Victor Yegorov <viy@nordlb.lv>

From: "Victor Yegorov" <viy@nordlb.lv>
To: Rudi Starcevic <rudi@oasis.net.au>
Cc: Postgres Performance <pgsql-performance@postgresql.org>
Date: 2003-05-15T00:12:39Z
Lists: pgsql-performance
* Rudi Starcevic <rudi@oasis.net.au> [15.05.2003 02:59]:
> Hi,
> 
> Can I confirm what this means then ..
> 
> For large table's each column with ref. inegritry I should create an 
> index on those columns ?

I think, that indicies are needed only at delete stage to decrease search
time of possible referencing rows.
Not only, of course, but when we speak about
INSERT/UPDATE/DELETE data it is so.

On the other side, indicies increases total query runtime, because for
each row deleted/updated/inserted it'll be necessary to update each index.

In my case, I at first drop "cyclic" constraints, do the job and then
restore them.


-- 

Victor Yegorov