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<!-- $PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.577 2008/01/31 21:31:33 tgl Exp $ --> |
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<!-- $PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.578 2008/02/02 23:30:23 tgl Exp $ --> |
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<!-- |
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Typical markup: |
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@ -697,13 +697,14 @@ current_date < 2017-11-17 |
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<para> |
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This feature dramatically increases performance for short data-modifying |
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transactions. The disadvantage is that because disk writes are |
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delayed, if the operating system crashes before data is written to |
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the disk, committed data will be lost. This feature is useful for |
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transactions. The disadvantage is that because disk writes are delayed, |
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if the database or operating system crashes before data is written to |
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the disk, committed data will be lost. This feature is useful for |
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applications that can accept some data loss. Unlike turning off |
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<varname>fsync</varname>, asynchronous commit does not put database |
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consistency at risk; the worst case is that after a database or system |
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crash the last few reportedly-committed transactions might be missing. |
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<varname>fsync</varname>, using asynchronous commit does not put |
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database consistency at risk; the worst case is that after a crash the |
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last few reportedly-committed transactions might not be committed after |
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all. |
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This feature is enabled by turning off <varname>synchronous_commit</> |
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(which can be done per-session or per-transaction, if some transactions |
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are critical and others are not). |
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