Improve performance of binary COPY FROM through better buffering. At least on Linux and macOS, fread() turns out to have far higher per-call overhead than one could wish. Reading 64KB of data at a time and then parceling it out with our own memcpy logic makes binary COPY from a file significantly faster --- around 30% in simple testing for cases with narrow text columns (on Linux ... even more on macOS).
In binary COPY from frontend, there's no per-call fread(), and this patch introduces an extra layer of memcpy'ing, but it still manages to eke out a small win. Apparently, the control-logic overhead in CopyGetData() is enough to be worth avoiding for small fetches. Bharath Rupireddy and Amit Langote, reviewed by Vignesh C, cosmetic tweaks by me Discussion: https://postgr.es/m/CALj2ACU5Bz06HWLwqSzNMN=Gupoj6Rcn_QVC+k070V4em9wu=a...@mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/0a0727ccfc5f4e2926623abe877bdc0b5bfd682e Modified Files -------------- src/backend/commands/copy.c | 118 +++++++++++++++++++++++++++++++------------- 1 file changed, 83 insertions(+), 35 deletions(-)
