Add single-item cache when looking at topmost XID of a subtrans XID This change affects SubTransGetTopmostTransaction(), used to find the topmost transaction ID of a given transaction ID. The cache is able to store one value, so as we can save the backend from unnecessary lookups at pg_subtrans/ on repetitive calls of this routine. There is a similar practice in transam.c, for example.
Author: Simon Riggs Reviewed-by: Andrey Borodin, Julien Rouhaud Discussion: https://postgr.es/m/CANbhV-G8Co=yq4v4bkw7mjdqvt68k_8a48naz_+8uqs7lrw...@mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/06f5295af673df795e8e70e28c43d61c2817b6df Modified Files -------------- src/backend/access/transam/subtrans.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
