> On Dec 11, 2017, at 12:40 PM, Andres Freund <andres@xxxxxxxxxxx> wrote: > > On 2017-12-11 11:26:51 -0800, Paul Ramsey wrote: >> On Mon, Dec 11, 2017 at 11:25 AM, Paul Ramsey <pramsey@xxxxxxxxxxxxxxxxx> wrote: >>> Is there anywhere any documentation on SearchSysCache? I find I end up >>> on these long spelunking expeditions through the code base for a >>> particular problem, find the answer after many hours, then forget >>> everything I learned because I don't exercise my knowledge frequently >>> enough. A decent reference guide would help a lot. What do the various >>> SysCacheIdentifier numbers mean/search, some examples, of usage, etc, >>> etc. >>> >>> I can accept if there are not, but it would be a shame to keep on >>> hunting like this if there were a good reference lying around. >> >> My particular hunt today is "for a given table relation, find any >> indexes that use the gist access method and are on a single attribute >> of type geometry". > > I don't think there's a way to do this with a single syscache, there > won't be an index than can cover all of these. I'd suggest using > RelationGetIndexList(), and then filtering for gist and attribute type > on the returned value. Thanks, A, I seem to be on the right path then. Loop through all indexes in RelationGetIndexList(), for those that have a relam == GIST_AM_OID, loop through the associated columns (looks like I actually have to use a SysScanDesc on AttributeRelationId) and look for atts that have the type I’m interested in, and if I find one, yay, we have a winner. Thanks, P
