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技術社區[雲棲]
PostgreSQL 10.0 preview 變化 - pg_xlog,pg_clog,pg_log目錄更名為pg_wal,pg_xact,log
標簽
PostgreSQL , 10.0 , pg_xact , pg_wal , log , pg_clog , pg_xlog , pg_log
背景
10.0 把幾個有一定“歧義”的目錄更名了。它們分別為
pg_xlog, pg_clog, pg_log
更名為
pg_wal, pg_xact, log
分別對應WAL（write ahead log）日誌，事務狀態日誌，日誌。
省得有人誤刪其中的LOG目錄中的文件。（還真有發生過）。
壞處是，如果有對應的程序用到了這幾個目錄名的，需要修改一下。
對應patch
Rename "pg_xlog" directory to "pg_wal".
author Robert Haas <rhaas@postgresql.org>
Thu, 20 Oct 2016 23:24:37 +0800 (11:24 -0400)
committer Robert Haas <rhaas@postgresql.org>
Thu, 20 Oct 2016 23:32:18 +0800 (11:32 -0400)
"xlog" is not a particularly clear abbreviation for "write-ahead log",
and it sometimes confuses users into believe that the contents of the
"pg_xlog" directory are not critical data, leading to unpleasant
consequences. So, rename the directory to "pg_wal".
This patch modifies pg_upgrade and pg_basebackup to understand both
the old and new directory layouts; the former is necessary given the
purpose of the tool, while the latter merely avoids an unnecessary
backward-compatibility break.
We may wish to consider renaming other programs, switches, and
functions which still use the old "xlog" naming to also refer to
"wal". However, that's still under discussion, so let's do just this
much for now.
Discussion: CAB7nPqTeC-8+zux8_-4ZD46V7YPwooeFxgndfsq5Rg8ibLVm1A@mail.gmail.com
Michael Paquier
Rename "pg_clog" directory to "pg_xact".
author Robert Haas <rhaas@postgresql.org>
Fri, 17 Mar 2017 21:46:58 +0800 (09:46 -0400)
committer Robert Haas <rhaas@postgresql.org>
Fri, 17 Mar 2017 21:48:38 +0800 (09:48 -0400)
Names containing the letters "log" sometimes confuse users into
believing that only non-critical data is present. It is hoped
this renaming will discourage ill-considered removals of transaction
status data.
Michael Paquier
Discussion: https://postgr.es/m/CA+Tgmoa9xFQyjRZupbdEFuwUerFTvC6HjZq1ud6GYragGDFFgA@mail.gmail.com
Change default of log_directory to 'log'
author Peter Eisentraut <peter_e@gmx.net>
Mon, 27 Mar 2017 22:34:33 +0800 (10:34 -0400)
committer Peter Eisentraut <peter_e@gmx.net>
Mon, 27 Mar 2017 22:34:33 +0800 (10:34 -0400)
The previous default 'pg_log' might have indicated by its "pg_" prefix
that it is an internal system directory. The new default is more in
line with the typical naming of directories with user-facing log files.
Together with the renaming of pg_clog and pg_xlog, this should clear up
that difference.
Author: Andreas Karlsson <andreas@proxel.se>
這個patch的討論，詳見郵件組，本文末尾URL。
PostgreSQL社區的作風非常嚴謹，一個patch可能在郵件組中討論幾個月甚至幾年，根據大家的意見反複的修正，patch合並到master已經非常成熟，所以PostgreSQL的穩定性也是遠近聞名的。
參考
最後更新：2017-04-21 00:30:37