Refactor COPY TO to use format callback functions.
authorMasahiko Sawada <msawada@postgresql.org>
Thu, 27 Feb 2025 23:03:52 +0000 (15:03 -0800)
committerMasahiko Sawada <msawada@postgresql.org>
Thu, 27 Feb 2025 23:03:52 +0000 (15:03 -0800)
commit2e4127b6d2d8f3a9d67a21d1905703d5be46970c
treea910ea8e9cbcec1243a4ae499f8b423c13b81753
parent555960a0fbf0590a744f36e90e69e2501dc06146
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 <kou@clear-code.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Tomas Vondra <tomas.vondra@enterprisedb.com>
Reviewed-by: Junwang Zhao <zhjwpku@gmail.com>
Discussion: https://postgr.es/m/20231204.153548.2126325458835528809.kou@clear-code.com
src/backend/commands/copyto.c
src/include/commands/copyapi.h [new file with mode: 0644]
src/tools/pgindent/typedefs.list