I am working in optimizer module of postgreSQL 9.4.1. I am trying to return a subplan for a query instead of full plan. For this I need to return an intermediate plan (or path) from the DP lattice (i.e. from RelOptInfo *standard_join_search() at allpaths.c) instead of the full optimal plan (which is from the last level of root->join_rel_level()).
while doing so I am getting error :variable not found in subplan target lists at function fix_join_expr_mutator at setrefs.c.
It will be great if you can give me some idea about why this error is happening, since this error is happening at fix_join_expr_mutator function at setrefs.c. Please give me more information about this portion of code. Also I would like to know for what targetlist stands for.