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| author | Fujii Masao <fujii@postgresql.org> | 2021-01-18 15:11:08 +0900 |
|---|---|---|
| committer | Fujii Masao <fujii@postgresql.org> | 2021-01-18 15:11:08 +0900 |
| commit | 708d165ddb92c54077a372acf6417e258dcb5fef (patch) | |
| tree | 89f4eda1b147b2072aaa2a9d1d1f2f7061b681b6 /doc/src | |
| parent | a3dc926009be833ea505eebd77ce4b72fe708b18 (diff) | |
| download | postgresql-708d165ddb92c54077a372acf6417e258dcb5fef.tar.gz postgresql-708d165ddb92c54077a372acf6417e258dcb5fef.zip | |
postgres_fdw: Add function to list cached connections to foreign servers.
This commit adds function postgres_fdw_get_connections() to return
the foreign server names of all the open connections that postgres_fdw
established from the local session to the foreign servers. This function
also returns whether each connection is valid or not.
This function is useful when checking all the open foreign server connections.
If we found some connection to drop, from the result of function, probably
we can explicitly close them by the function that upcoming commit will add.
This commit bumps the version of postgres_fdw to 1.1 since it adds
new function.
Author: Bharath Rupireddy, tweaked by Fujii Masao
Reviewed-by: Zhijie Hou, Alexey Kondratov, Zhihong Yu, Fujii Masao
Discussion: https://postgr.es/m/2d5cb0b3-a6e8-9bbb-953f-879f47128faa@oss.nttdata.com
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/postgres-fdw.sgml | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/doc/src/sgml/postgres-fdw.sgml b/doc/src/sgml/postgres-fdw.sgml index e6fd2143c10..6a91926da83 100644 --- a/doc/src/sgml/postgres-fdw.sgml +++ b/doc/src/sgml/postgres-fdw.sgml @@ -479,6 +479,38 @@ OPTIONS (ADD password_required 'false'); </sect3> </sect2> +<sect2> + <title>Functions</title> + + <variablelist> + <varlistentry> + <term><function>postgres_fdw_get_connections(OUT server_name text, OUT valid boolean) returns setof record</function></term> + <listitem> + <para> + This function returns the foreign server names of all the open + connections that <filename>postgres_fdw</filename> established from + the local session to the foreign servers. It also returns whether + each connection is valid or not. <literal>false</literal> is returned + if the foreign server connection is used in the current local + transaction but its foreign server or user mapping is changed or + dropped, and then such invalid connection will be closed at + the end of that transaction. <literal>true</literal> is returned + otherwise. If there are no open connections, no record is returned. + Example usage of the function: + <screen> +postgres=# SELECT * FROM postgres_fdw_get_connections() ORDER BY 1; + server_name | valid +-------------+------- + loopback1 | t + loopback2 | f +</screen> + </para> + </listitem> + </varlistentry> + </variablelist> + +</sect2> + <sect2> <title>Connection Management</title> |