Refactor COPY TO to use format callback functions. This commit introduces a new CopyToRoutine struct, which is a set of callback routines to copy tuples in a specific format. It also makes the existing formats (text, CSV, and binary) utilize these format callbacks.
This change is a preliminary step towards making the COPY TO command extensible in terms of output formats. Additionally, this refactoring contributes to a performance improvement by reducing the number of "if" branches that need to be checked on a per-row basis when sending field representations in text or CSV mode. The performance benchmark results showed ~5% performance gain in text or CSV mode. Author: Sutou Kouhei <k...@clear-code.com> Reviewed-by: Masahiko Sawada <sawada.m...@gmail.com> Reviewed-by: Michael Paquier <mich...@paquier.xyz> Reviewed-by: Andres Freund <and...@anarazel.de> Reviewed-by: Tomas Vondra <tomas.von...@enterprisedb.com> Reviewed-by: Junwang Zhao <zhjw...@gmail.com> Discussion: https://postgr.es/m/20231204.153548.2126325458835528809....@clear-code.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/2e4127b6d2d8f3a9d67a21d1905703d5be46970c Modified Files -------------- src/backend/commands/copyto.c | 438 ++++++++++++++++++++++++++------------- src/include/commands/copyapi.h | 57 +++++ src/tools/pgindent/typedefs.list | 1 + 3 files changed, 355 insertions(+), 141 deletions(-)
