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@ -10,7 +10,7 @@ |
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alink="#0000ff"> |
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alink="#0000ff"> |
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<H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1> |
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<H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1> |
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<P>Last updated: Mon Jan 31 21:35:15 EST 2005</P> |
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<P>Last updated: Mon Jan 31 21:40:28 EST 2005</P> |
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<P>Current maintainer: Bruce Momjian (<A href= |
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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>) |
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"mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>) |
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@ -1040,25 +1040,25 @@ length</TD></TR> |
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uncertain how a cross-database query should even behave.</P> |
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uncertain how a cross-database query should even behave.</P> |
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<P><I>contrib/dblink</I> allows cross-database queries using |
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<P><I>contrib/dblink</I> allows cross-database queries using |
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function calls. Of course, a client can make simultaneous |
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function calls. Of course, a client can also make simultaneous |
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connections to different databases and merge the results on the |
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connections to different databases and merge the results on the |
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client side.</P> |
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client side.</P> |
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<H4><A name="4.19">4.19</A>) How do I return multiple rows or |
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<H4><A name="4.19">4.19</A>) How do I return multiple rows or |
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columns from a function?</H4> |
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columns from a function?</H4> |
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<P>In 7.3, you can easily return multiple rows or columns from a |
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<P>It is easy using set-returning functions, |
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function, |
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<a href="http://techdocs.postgresql.org/guides/SetReturningFunctions"> |
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<a href="http://techdocs.postgresql.org/guides/SetReturningFunctions"> |
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http://techdocs.postgresql.org/guides/SetReturningFunctions</a>. |
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http://techdocs.postgresql.org/guides/SetReturningFunctions</a>. |
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<H4><A name="4.20">4.20</A>) Why can't I reliably create/drop |
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<H4><A name="4.20">4.20</A>) Why can't I reliably create/drop |
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temporary tables in PL/PgSQL functions?</H4> |
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temporary tables in PL/PgSQL functions?</H4> |
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<P>PL/PgSQL caches function contents, and an unfortunate side effect |
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<P>PL/PgSQL caches function scripts, and an unfortunate side effect |
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is that if a PL/PgSQL function accesses a temporary table, and that |
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is that if a PL/PgSQL function accesses a temporary table, and that |
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table is later dropped and recreated, and the function called |
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table is later dropped and recreated, and the function called again, |
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again, the function will fail because the cached function contents |
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the function will fail because the cached function contents still |
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still point to the old temporary table. The solution is to use |
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point to the old temporary table. The solution is to use |
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<SMALL>EXECUTE</SMALL> for temporary table access in PL/PgSQL. This |
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<SMALL>EXECUTE</SMALL> for temporary table access in PL/PgSQL. This |
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will cause the query to be reparsed every time.</P> |
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will cause the query to be reparsed every time.</P> |
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@ -1075,8 +1075,7 @@ length</TD></TR> |
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encrypted transport, such as stunnel or ssh, rather than PostgreSQL's |
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encrypted transport, such as stunnel or ssh, rather than PostgreSQL's |
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native SSL connections.) |
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native SSL connections.) |
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<LI>Database user passwords are automatically encrypted when stored in |
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<LI>Database user passwords are automatically encrypted when stored in |
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version 7.3. In previous versions, you must enable the option |
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the system tables.</LI> |
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<I>PASSWORD_ENCRYPTION</I> in <I>postgresql.conf</I>.</LI> |
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<LI>The server can run using an encrypted file system.</LI> |
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<LI>The server can run using an encrypted file system.</LI> |
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</UL> |
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</UL> |
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