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Update fsync FAQ item.
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doc/FAQ

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Frequently Asked Questions (FAQ) for PostgreSQL
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Last updated: Mon Jun 10 16:44:55 EDT 2002
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Last updated: Mon Jun 10 22:22:31 EDT 2002
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Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
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reduce lock contention.
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Performance
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PostgreSQL runs in two modes. Normal fsync mode flushes every
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completed transaction to disk, guaranteeing that if the OS
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crashes or loses power in the next few seconds, all your data
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is safely stored on disk. In this mode, we are slower than most
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commercial databases, partly because few of them do such
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conservative flushing to disk in their default modes. In
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no-fsync mode, we are usually faster than commercial databases,
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though in this mode, an OS crash could cause data corruption.
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We are working to provide an intermediate mode that suffers
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less performance overhead than full fsync mode, and will allow
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data integrity within 30 seconds of an OS crash.
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PostgreSQL has performance similar to other commercial and open
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source databases. it is faster for some things, slower for
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others.
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In comparison to MySQL or leaner database systems, we are
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slower on inserts/updates because we have transaction overhead.
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Of course, MySQL does not have any of the features mentioned in
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the Features section above. We are built for flexibility and
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features, though we continue to improve performance through
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profiling and source code analysis. There is an interesting Web
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page comparing PostgreSQL to MySQL at
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http://openacs.org/why-not-mysql.html
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We handle each user connection by creating a Unix process.
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Backend processes share data buffers and locking information.
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With multiple CPUs, multiple backends can easily run on
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different CPUs.
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the Features section above. We are built for reliability and
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features, though we continue to improve performance in every
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release. There is an interesting Web page comparing PostgreSQL
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to MySQL at http://openacs.org/why-not-mysql.html
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Reliability
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We realize that a DBMS must be reliable, or it is worthless. We

doc/src/FAQ/FAQ.html

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alink="#0000ff">
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<H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1>
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<P>Last updated: Mon Jun 10 16:44:55 EDT 2002</P>
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<P>Last updated: Mon Jun 10 22:22:31 EDT 2002</P>
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<P>Current maintainer: Bruce Momjian (<A href=
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"mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>)<BR>
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<DT><B>Performance</B></DT>
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<DD>PostgreSQL runs in two modes. Normal <I>fsync</I> mode
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flushes every completed transaction to disk, guaranteeing that if
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the OS crashes or loses power in the next few seconds, all your
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data is safely stored on disk. In this mode, we are slower than
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most commercial databases, partly because few of them do such
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conservative flushing to disk in their default modes. In
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<I>no-fsync</I> mode, we are usually faster than commercial
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databases, though in this mode, an OS crash could cause data
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corruption. We are working to provide an intermediate mode that
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suffers less performance overhead than full fsync mode, and will
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allow data integrity within 30 seconds of an OS crash.<BR>
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<DD>PostgreSQL has performance similar to other commercial and
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open source databases. it is faster for some things, slower for
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others.
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<BR>
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In comparison to MySQL or leaner database systems, we are slower
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In comparison to MySQL or leaner database systems, we are slower
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on inserts/updates because we have transaction overhead. Of
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course, MySQL does not have any of the features mentioned in the
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<I>Features</I> section above. We are built for flexibility and
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features, though we continue to improve performance through
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profiling and source code analysis. There is an interesting Web
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page comparing PostgreSQL to MySQL at <A href=
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"http://openacs.org/why-not-mysql.html">http://openacs.org/why-not-mysql.html</A><BR>
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<I>Features</I> section above. We are built for reliability and
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features, though we continue to improve performance in every
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release. There is an interesting Web page comparing PostgreSQL to
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MySQL at <A href= "http://openacs.org/why-not-mysql.html">
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http://openacs.org/why-not-mysql.html</A><BR>
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<BR>
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We handle each user connection by creating a Unix process.
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Backend processes share data buffers and locking information.
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With multiple CPUs, multiple backends can easily run on different
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CPUs.<BR>
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<BR>
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</DD>
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