Re: [Engine-devel] Opimizing Postgres Stored Procedures

From: "Laszlo Hornyak" <lhornyak(a)redhat.com&gt; To: "Eli Mesika" <emesika(a)redhat.com&gt; Cc: "engine-devel" <engine-devel(a)ovirt.org&gt; Sent: Tuesday, August 27, 2013 11:40:27 AM Subject: Re: [Engine-devel] Opimizing Postgres Stored Procedures Hi Eli, Most of the functions that we have in the DB are doing very simple jobs like run a query, insert/update and I see that now you have all QUERY functions as STABLE. My questions: Is this required for new functions from now on?

Is this done in order to improve performance?

Thank you, Laszlo ----- Original Message ----- > From: "Eli Mesika" <emesika(a)redhat.com&gt; > To: "engine-devel" <engine-devel(a)ovirt.org&gt; > Sent: Monday, August 26, 2013 11:22:20 AM > Subject: [Engine-devel] Opimizing Postgres Stored Procedures > > Hi > > I had merged the following patch > http://gerrit.ovirt.org/#/c/17962/ > > This patch introduce usage of the IMMUTABLE, STABLE and STRICT keywords in > order to boost performance of the Postgres SPs. > > Please make sure that your current/and future DB scripts applied that. > > > Volatility > ---------- > * A function should be marked as IMMUTABLE if it doesn't change the > database, > and if it doesn't perform any lookups (even for database configuration > values) during its operation. > * A function should be marked STABLE if it doesn't change the database, but > might perform lookups (IMMUTABLE is preferable if function meets the > requirements). > * A function doesn't need to be marked VOLATILE, because that's the > default. > > STRICTNESS > ---------- > A function should be marked STRICT if it should return NULL when it is > passed > a NULL argument, and then the function won't even be called if it is indeed > passed a NULL argument. > > > I am available for any questions. > > Thanks > > Eli > _______________________________________________ > Engine-devel mailing list > Engine-devel(a)ovirt.org > http://lists.ovirt.org/mailman/listinfo/engine-devel >