@@ -143,6 +143,7 @@ <H2 align="center">Operational Questions</H2>
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from a function?< BR >
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< A href ="#4.26 "> 4.26</ A > ) Why can't I reliably create/drop
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temporary tables in PL/PgSQL functions?< BR >
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+ < A href ="#4.27 "> 4.27</ A > ) What replication options are available?< BR >
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< H2 align ="center "> Extending PostgreSQL</ H2 >
@@ -1346,12 +1347,14 @@ <H4><A name="4.23">4.23</A>) How do I perform an outer join?</H4>
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< H4 > < A name ="4.24 "> 4.24</ A > ) How do I perform queries using
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multiple databases?</ H4 >
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- < P > There is no way to queryany databaseexcept the current one.
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+ < P > There is no way to querya databaseother than the current one.
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Because PostgreSQL loads database-specific system catalogs, it is
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uncertain how a cross-database query should even behave.</ P >
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- < P > Of course, a client can make simultaneous connections to
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- different databases and merge the information that way.</ P >
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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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+ connections to different databases and merge the results on the
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+ client side.</ P >
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< H4 > < A name ="4.25 "> 4.25</ A > ) How do I return multiple rows or
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columns from a function?</ H4 >
@@ -1364,13 +1367,19 @@ <H4><A name="4.25">4.25</A>) How do I return multiple rows or
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< H4 > < A name ="4.26 "> 4.26</ A > ) Why can't I reliably create/drop
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temporary tables in PL/PgSQL functions?</ H4 >
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- PL/PgSQL caches function contents, and an unfortunate side effect
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+ < P > PL/PgSQL caches function contents, 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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table is later dropped and recreated, and the function called
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again, the function will fail because the cached function contents
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still 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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- will cause the query to be reparsed every time.
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+ will cause the query to be reparsed every time.</ P >
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+ < H4 > < A name ="4.27 "> 4.27</ A > ) What replication options are available?
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+ </ H4 >
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+ < P > There are several master/slave replication solutions available.
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+ These allow only one server to make database changes and the slave
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+ merely allow database reading.
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< HR >
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