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3c49c6facb
Since some preparation work had already been done, the only source changes left were changing empty-element tags like <xref linkend="foo"> to <xref linkend="foo"/>, and changing the DOCTYPE. The source files are still named *.sgml, but they are actually XML files now. Renaming could be considered later. In the build system, the intermediate step to convert from SGML to XML is removed. Everything is build straight from the source files again. The OpenSP (or the old SP) package is no longer needed. The documentation toolchain instructions are updated and are much simpler now. Peter Eisentraut, Alexander Lakhin, Jürgen Purtz
114 lines
3.4 KiB
Plaintext
114 lines
3.4 KiB
Plaintext
<!-- doc/src/sgml/ref/pgtestfsync.sgml -->
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<refentry id="pgtestfsync">
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<indexterm zone="pgtestfsync">
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<primary>pg_test_fsync</primary>
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</indexterm>
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<refmeta>
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<refentrytitle><application>pg_test_fsync</application></refentrytitle>
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<manvolnum>1</manvolnum>
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<refmiscinfo>Application</refmiscinfo>
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</refmeta>
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<refnamediv>
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<refname>pg_test_fsync</refname>
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<refpurpose>determine fastest <varname>wal_sync_method</varname> for <productname>PostgreSQL</productname></refpurpose>
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</refnamediv>
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<refsynopsisdiv>
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<cmdsynopsis>
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<command>pg_test_fsync</command>
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<arg rep="repeat"><replaceable>option</replaceable></arg>
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</cmdsynopsis>
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</refsynopsisdiv>
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<refsect1>
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<title>Description</title>
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<para>
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<application>pg_test_fsync</application> is intended to give you a reasonable
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idea of what the fastest <xref linkend="guc-wal-sync-method"/> is on your
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specific system,
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as well as supplying diagnostic information in the event of an identified I/O
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problem. However, differences shown by
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<application>pg_test_fsync</application> might not make any significant
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difference in real database throughput, especially since many database servers
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are not speed-limited by their write-ahead logs.
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<application>pg_test_fsync</application> reports average file sync operation
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time in microseconds for each <literal>wal_sync_method</literal>, which can also be used to
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inform efforts to optimize the value of <xref linkend="guc-commit-delay"/>.
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</para>
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</refsect1>
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<refsect1>
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<title>Options</title>
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<para>
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<application>pg_test_fsync</application> accepts the following
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command-line options:
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<variablelist>
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<varlistentry>
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<term><option>-f</option></term>
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<term><option>--filename</option></term>
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<listitem>
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<para>
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Specifies the file name to write test data in.
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This file should be in the same file system that the
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<filename>pg_wal</filename> directory is or will be placed in.
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(<filename>pg_wal</filename> contains the <acronym>WAL</acronym> files.)
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The default is <filename>pg_test_fsync.out</filename> in the current
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directory.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><option>-s</option></term>
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<term><option>--secs-per-test</option></term>
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<listitem>
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<para>
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Specifies the number of seconds for each test. The more time
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per test, the greater the test's accuracy, but the longer it takes
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to run. The default is 5 seconds, which allows the program to
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complete in under 2 minutes.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><option>-V</option></term>
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<term><option>--version</option></term>
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<listitem>
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<para>
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Print the <application>pg_test_fsync</application> version and exit.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><option>-?</option></term>
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<term><option>--help</option></term>
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<listitem>
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<para>
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Show help about <application>pg_test_fsync</application> command line
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arguments, and exit.
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</para>
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</listitem>
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</varlistentry>
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</variablelist>
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</para>
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</refsect1>
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<refsect1>
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<title>See Also</title>
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<simplelist type="inline">
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<member><xref linkend="app-postgres"/></member>
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</simplelist>
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</refsect1>
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</refentry>
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