pg_test_fsync — determine fastest
wal_sync_method for PostgreSQL
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.
pg_test_fsync accepts the following command-line options:
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. (
contains the WAL
files.) The default is
pg_test_fsync.out in the current
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.
Print the pg_test_fsync version and exit.
Show help about pg_test_fsync command line arguments, and exit.
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