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pg_test_fsync
pg_test_fsync — determine fastest wal_sync_method for PostgreSQL
Reading PostgreSQL 18.6.
Description
pg_test_fsync — determine fastest wal_sync_method for PostgreSQL
- Documented executable
- pg_test_fsync
- Executable version
- 18.6
- Reference inventory
- Server applications
- Option definition groups
- 4
Usage
pg_test_fsync [ option ...]Documented options
| Option and arguments | Description |
|---|---|
| -f --filename | Specifies the file name to write test data in. This file should be in the same file system that the pg_wal directory is or will be placed in. ( pg_wal contains the WAL files.) The default is pg_test_fsync.out in the current directory. |
| -s --secs-per-test | Specifies the number of seconds for each test. The more time per test, the greater the test's accuracy, but the longer it takes to run. The default is 5 seconds, which allows the program to complete in under 2 minutes. |
| -V --version | Print the pg_test_fsync version and exit. |
| -? --help | Show help about pg_test_fsync command line arguments, and exit. |
Manual definition
pg_test_fsync
pg_test_fsync — determine fastest wal_sync_method for PostgreSQL
Synopsis
pg_test_fsync [option...]
Description
pg_test_fsync is intended to give you a reasonable idea of what the fastest wal_sync_method is on your specific system, as well as supplying diagnostic information in the event of an identified I/O problem. However, differences shown by pg_test_fsync might not make any significant difference in real database throughput, especially since many database servers are not speed-limited by their write-ahead logs. pg_test_fsync reports average file sync operation time in microseconds for each wal_sync_method, which can also be used to inform efforts to optimize the value of commit_delay.
Options
pg_test_fsync accepts the following command-line options:
-f--filename-
Specifies the file name to write test data in. This file should be in the same file system that the
pg_waldirectory is or will be placed in. (pg_walcontains the WAL files.) The default ispg_test_fsync.outin the current directory. -s--secs-per-test-
Specifies the number of seconds for each test. The more time per test, the greater the test's accuracy, but the longer it takes to run. The default is 5 seconds, which allows the program to complete in under 2 minutes.
-V--version-
Print the pg_test_fsync version and exit.
-?--help-
Show help about pg_test_fsync command line arguments, and exit.
Environment
The environment variable PG_COLOR specifies whether to use color in diagnostic messages. Possible values are always, auto and never.
See Also
postgresDocumentation and source
Source build
- Version
- 18.6
- Build
- https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2
- Source fingerprint
ee8d1a3612338fd9adf250730cb640fcc5233b5491337cc00a316a44e3a0b9f8
Compare versions
PostgreSQL 17 → 18: unchanged.
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Related entries
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