On May 11, 2017 11:31:02 AM PDT, Tom Lane <t...@sss.pgh.pa.us> wrote: >Bruce Momjian <br...@momjian.us> writes: >> Good point. I think we need to do some measurements to see if the >> parser-only stage is actually significant. I have a hunch that >> commercial databases have much heavier parsers than we do. > >FWIW, gram.y does show up as significant in many of the profiles I >take. >I speculate that this is not so much that it eats many CPU cycles, as >that >the constant tables are so large as to incur lots of cache misses. >scan.l >is not quite as big a deal for some reason, even though it's also >large.
And that there's a lot of unpredictable branches, leading to a lot if pipeline stalls. Andres -- Sent from my Android device with K-9 Mail. Please excuse my brevity. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
