Alexander Korotkov wrote: > Hi! > > Thank you for review! So. Before this version of the patch was posted in Nov 4th 2015, both Tom and Heikki had said essentially "CREATE ACCESS METHOD is worthless, let's pursue this stuff without those commands". http://www.postgresql.org/message-id/54730dfd.2060...@vmware.com (Nov 2014) http://www.postgresql.org/message-id/26822.1414516...@sss.pgh.pa.us (Oct 2014)
And then Alexander posted this version, without any discussion that evidenced that those old objections were overridden. What happened here? Did somebody discuss this in unarchived meetings? If so, it would be good to know about that in this thread. I noticed this state of affairs because I started reading the complete thread in order to verify whether a consensus had been reached regarding the move of IndexQualInfo and GenericCosts to selfuncs.h. But I only see that Jim Nasby mentioned it and Alexander said "yes they move"; nothing else. The reason for raising this is that, according to Alexander, new index AMs will want to use those structs; but current index AMs only include index_selfuncs.h, and none of them includes selfuncs.h, so it seems completely wrong to be importing all the planner knowledge embodied in selfuncs.h into extension index AMs. One observation is that the bloom AM patch (0003 of this series) uses GenericCosts but not IndexQualInfo. But btcostestimate() and gincostestimate() both use IndexQualInfo, so other AMs might well want to use it too. We could move GenericCosts and the prototype for genericcostestimate() to index_selfuncs.h; that much is pretty reasonable. But I'm not sure what to do about IndexQualInfo. We could just add forward struct declarations for RestrictInfo and Node to index_selfuncs.h. But then the extension code is going to have to import the includes were those are defined anyway. Certainly it seems that deconstruct_indexquals() (which returns a list of IndexQualInfo) is going to be needed by extension index AMs, at least ... I've made a few edits to the patch already, but I need to do some more testing. Particularly I would like to understand the relcache issues to figure out whether the current one is right. -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
