"Mark Cave-Ayland" <[EMAIL PROTECTED]> writes: > I'm trying to mark a GiST index as lossy using the RECHECK operator as > part of some work on PostGIS, but what happens is that the original > operator function is never reapplied to the results of the index scan.
You sure? I'm pretty sure that a number of the contrib gist index opclasses would fail their regression tests if this were broken. As of 7.5 you cannot see the reapplication in the generated plan's filter condition; perhaps that got you confused? 2004-01-05 23:31 tgl * src/: backend/executor/nodeIndexscan.c, backend/nodes/copyfuncs.c, backend/nodes/outfuncs.c, backend/optimizer/path/costsize.c, backend/optimizer/plan/createplan.c, backend/optimizer/plan/setrefs.c, include/nodes/execnodes.h, include/nodes/plannodes.h: Instead of rechecking lossy index operators by putting them into the regular qpqual ('filter condition'), add special-purpose code to nodeIndexscan.c to recheck them. This ends being almost no net addition of code, because the removal of planner code balances out the extra executor code, but it is significantly more efficient when a lossy operator is involved in an OR indexscan. The old implementation had to recheck the entire indexqual in such cases. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match