Thread: pgsql: Don't use bms_membership() in cases where we don't need to
Don't use bms_membership() in cases where we don't need to 00b41463c adjusted Bitmapset so that an empty set is always represented as NULL. This makes checking for empty sets far cheaper than it used to be. There were various places in the code where we'd call bms_membership() to handle the 3 possible BMS_Membership values. For the BMS_SINGLETON case, we'd also call bms_singleton_member() to find the single set member. This can now be done in a more optimal way by first checking if the set is NULL and then not bothering with bms_membership() and simply call bms_get_singleton_member() instead to find the single member. This function will return false if there are multiple members in the set. Here we also tidy up some logic in examine_variable() for the single member case. There's now no need to call bms_is_member() as we've already established that we're working with a singleton Bitmapset, so we can just check if varRelid matches the singleton member. Reviewed-by: Richard Guo Discussion: https://postgr.es/m/CAApHDvqW+CxNPcY245GaWiuqkkqgTudtG2ncGvvSjGn2wdTZLA@mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/930d2b442ff12e6d466a8c62cecdf3f17680aa3e Modified Files -------------- src/backend/optimizer/plan/initsplan.c | 32 ++++++++++++++------------ src/backend/utils/adt/selfuncs.c | 42 ++++++++++++++++++---------------- 2 files changed, 39 insertions(+), 35 deletions(-)