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| author | Andres Freund <andres@anarazel.de> | 2017-09-19 22:03:48 -0700 |
|---|---|---|
| committer | Andres Freund <andres@anarazel.de> | 2017-09-19 22:03:48 -0700 |
| commit | fc49e24fa69a15efacd5b8958115ed9c43c48f9a (patch) | |
| tree | a1399d0d533c1cfa864e545a17000e7b6df6f43d /src/bin/pg_test_fsync | |
| parent | 5ada1fcd0c30be1b0b793a802cf6da386a6c1925 (diff) | |
| download | postgresql-fc49e24fa69a15efacd5b8958115ed9c43c48f9a.tar.gz postgresql-fc49e24fa69a15efacd5b8958115ed9c43c48f9a.zip | |
Make WAL segment size configurable at initdb time.
For performance reasons a larger segment size than the default 16MB
can be useful. A larger segment size has two main benefits: Firstly,
in setups using archiving, it makes it easier to write scripts that
can keep up with higher amounts of WAL, secondly, the WAL has to be
written and synced to disk less frequently.
But at the same time large segment size are disadvantageous for
smaller databases. So far the segment size had to be configured at
compile time, often making it unrealistic to choose one fitting to a
particularly load. Therefore change it to a initdb time setting.
This includes a breaking changes to the xlogreader.h API, which now
requires the current segment size to be configured. For that and
similar reasons a number of binaries had to be taught how to recognize
the current segment size.
Author: Beena Emerson, editorialized by Andres Freund
Reviewed-By: Andres Freund, David Steele, Kuntal Ghosh, Michael
Paquier, Peter Eisentraut, Robert Hass, Tushar Ahuja
Discussion: https://postgr.es/m/CAOG9ApEAcQ--1ieKbhFzXSQPw_YLmepaa4hNdnY5+ZULpt81Mw@mail.gmail.com
Diffstat (limited to 'src/bin/pg_test_fsync')
| -rw-r--r-- | src/bin/pg_test_fsync/pg_test_fsync.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/src/bin/pg_test_fsync/pg_test_fsync.c b/src/bin/pg_test_fsync/pg_test_fsync.c index c607b5371c0..e6f7ef85579 100644 --- a/src/bin/pg_test_fsync/pg_test_fsync.c +++ b/src/bin/pg_test_fsync/pg_test_fsync.c @@ -64,7 +64,7 @@ static const char *progname; static int secs_per_test = 5; static int needs_unlink = 0; -static char full_buf[XLOG_SEG_SIZE], +static char full_buf[DEFAULT_XLOG_SEG_SIZE], *buf, *filename = FSYNC_FILENAME; static struct timeval start_t, @@ -209,7 +209,7 @@ prepare_buf(void) int ops; /* write random data into buffer */ - for (ops = 0; ops < XLOG_SEG_SIZE; ops++) + for (ops = 0; ops < DEFAULT_XLOG_SEG_SIZE; ops++) full_buf[ops] = random(); buf = (char *) TYPEALIGN(XLOG_BLCKSZ, full_buf); @@ -226,7 +226,8 @@ test_open(void) if ((tmpfile = open(filename, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR)) == -1) die("could not open output file"); needs_unlink = 1; - if (write(tmpfile, full_buf, XLOG_SEG_SIZE) != XLOG_SEG_SIZE) + if (write(tmpfile, full_buf, DEFAULT_XLOG_SEG_SIZE) != + DEFAULT_XLOG_SEG_SIZE) die("write failed"); /* fsync now so that dirty buffers don't skew later tests */ |