Store information about elided nodes in the final plan. An extension (or core code) might want to reconstruct the planner's choice of join order from the final plan. To do so, it must be possible to find all of the RTIs that were part of the join problem in that plan. Commit adbad833f3d9e9176e8d7005f15ea6056900227d, together with the earlier work in 8c49a484e8ebb0199fba4bd68eaaedaf49b48ed0, is enough to let us match up RTIs we see in the final plan with RTIs that we see during the planning cycle, but we still have a problem if the planner decides to drop some RTIs out of the final plan altogether.
To fix that, when setrefs.c removes a SubqueryScan, single-child Append, or single-child MergeAppend from the final Plan tree, record the type of the removed node and the RTIs that the removed node would have scanned in the final plan tree. It would be natural to record this information on the child of the removed plan node, but that would require adding an additional pointer field to type Plan, which seems undesirable. So, instead, store the information in a separate list that the executor need never consult, and use the plan_node_id to identify the plan node with which the removed node is logically associated. Also, update pg_overexplain to display these details. Reviewed-by: Lukas Fittl <[email protected]> Reviewed-by: Jakub Wartak <[email protected]> Reviewed-by: Greg Burd <[email protected]> Reviewed-by: Jacob Champion <[email protected]> Reviewed-by: Amit Langote <[email protected]> Reviewed-by: Haibo Yan <[email protected]> Reviewed-by: Alexandra Wang <[email protected]> Discussion: http://postgr.es/m/CA+TgmoZ-Jh1T6QyWoCODMVQdhTUPYkaZjWztzP1En4=zhok...@mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/0d4391b265f83023d0b7eed71817517410f76e60 Modified Files -------------- contrib/pg_overexplain/expected/pg_overexplain.out | 16 +++++-- contrib/pg_overexplain/pg_overexplain.c | 39 ++++++++++++++++ src/backend/optimizer/plan/planner.c | 1 + src/backend/optimizer/plan/setrefs.c | 52 +++++++++++++++++++++- src/include/nodes/pathnodes.h | 3 ++ src/include/nodes/plannodes.h | 20 +++++++++ src/tools/pgindent/typedefs.list | 1 + 7 files changed, 127 insertions(+), 5 deletions(-)
