Thread: pgsql: Speed up creation of command completion tags
Speed up creation of command completion tags The building of command completion tags could often be seen showing up in profiles when running high tps workloads. The query completion tags were being built with snprintf, which is slow at the best of times when compared with more manual ways of formatting strings. Here we introduce BuildQueryCompletionString() to do this job for us. We also now store the completion tag's strlen in the CommandTagBehavior struct so that we can quickly memcpy this number of bytes into the completion tag string. Appending the rows affected is done via pg_ulltoa_n. BuildQueryCompletionString returns the length of the built string. This saves us having to call strlen to figure out how many bytes to pass to pq_putmessage(). Author: David Rowley, Andres Freund Reviewed-by: Andres Freund Discussion: https://postgr.es/m/CAHoyFK-Xwqc-iY52shj0G+8K9FJpse+FuZ36XBKy78wDVnd=Qg@mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/ac998020802b742303979a13692afa7b2084d0e9 Modified Files -------------- src/backend/tcop/cmdtag.c | 72 +++++++++++++++++++++++++++++++++++++++++++++-- src/backend/tcop/dest.c | 29 +++---------------- src/include/tcop/cmdtag.h | 5 ++++ src/include/tcop/dest.h | 2 -- 4 files changed, 78 insertions(+), 30 deletions(-)