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From: Bruce Momjian on 18 Feb 2010 22:34 Robert Haas wrote: > On Sat, Dec 19, 2009 at 11:01 PM, Robert Haas <robertmhaas(a)gmail.com> wrote: > > On Sat, Dec 19, 2009 at 4:46 PM, Tom Lane <tgl(a)sss.pgh.pa.us> wrote: > >> Robert Haas <robertmhaas(a)gmail.com> writes: > >>> On Sat, Dec 19, 2009 at 3:01 PM, Tom Lane <tgl(a)sss.pgh.pa.us> wrote: > >>>> I believe the correct approach is probably to treat values that need to > >>>> be propagated into the inner side as executor parameters. ?This could > >>>> replace the existing, rather crocky, management of values passed into a > >>>> nestloop inner indexscan. > >> > >>> What is the best place to look for the existing, rather crocky code? > >> > >> Follow the second argument of ExecReScan from nodeNestloop to > >> nodeIndexscan. > > > > Yeah, this is grotty. ?It appears that the comment introducing > > ExecReScan() is somewhat incorrect. ?It asserts that exprCtxt is used > > only > > Sigh. > > ...is used only for index scans. However, it's actually also used for > bitmap scans (both heap and index) and TID scans. Also, there appears > to be an effort by nodes that don't use exprCtxt directly to propagate > down through the node tree, which doesn't seem to make much sense if > this is only intended to be used on the inner side of a nestloop. Does some comment need to be updated? -- Bruce Momjian <bruce(a)momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
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