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| author | Andres Freund <andres@anarazel.de> | 2014-10-01 13:13:59 +0200 |
|---|---|---|
| committer | Andres Freund <andres@anarazel.de> | 2014-10-01 13:22:17 +0200 |
| commit | 0ef3c29a4b43e72d93cff65a17a9ccccff87618d (patch) | |
| tree | dd09f894757e2b09e91798669d9c16c96cfbe64d /doc/src | |
| parent | ef8863844bb0b0dab7b92c5f278302a42b4bf05a (diff) | |
| download | postgresql-0ef3c29a4b43e72d93cff65a17a9ccccff87618d.tar.gz postgresql-0ef3c29a4b43e72d93cff65a17a9ccccff87618d.zip | |
Improve documentation about binary/textual output mode for output plugins.
Also improve related error message as it contributed to the confusion.
Discussion: CAB7nPqQrqFzjqCjxu4GZzTrD9kpj6HMn9G5aOOMwt1WZ8NfqeA@mail.gmail.com,
CAB7nPqQXc_+g95zWnqaa=mVQ4d3BVRs6T41frcEYi2ocUrR3+A@mail.gmail.com
Per discussion between Michael Paquier, Robert Haas and Andres Freund
Backpatch to 9.4 where logical decoding was introduced.
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/logicaldecoding.sgml | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/doc/src/sgml/logicaldecoding.sgml b/doc/src/sgml/logicaldecoding.sgml index e6880d0ac58..1f56b39df94 100644 --- a/doc/src/sgml/logicaldecoding.sgml +++ b/doc/src/sgml/logicaldecoding.sgml @@ -355,6 +355,24 @@ CREATE TABLE another_catalog_table(data text) WITH (user_catalog_table = true); </para> </sect2> + <sect2 id="logicaldecoding-output-mode"> + <title>Output Modes</title> + <para> + Output plugin callbacks can pass data to the consumer in nearly arbitrary + formats. For some use cases, like viewing the changes via SQL, returning + data in a datatype that can contain arbitrary data (i.e. bytea) is + cumbersome. If the output plugin only outputs textual data in the + server's encoding it can declare that by + setting <literal>OutputPluginOptions.output_mode</> + to <literal>OUTPUT_PLUGIN_TEXTUAL_OUTPUT</> instead + of <literal>OUTPUT_PLUGIN_BINARY_OUTPUT</> in + the <link linkend="logicaldecoding-output-plugin-startup">startup + callback</>. In that case all the data has to be in the server's encoding + so a <type>text</> can contain it. This is checked in assertion enabled + builds. + </para> + </sect2> + <sect2 id="logicaldecoding-output-plugin-callbacks"> <title>Output Plugin Callbacks</title> <para> @@ -405,7 +423,8 @@ typedef struct OutputPluginOptions </programlisting> <literal>output_type</literal> has to either be set to <literal>OUTPUT_PLUGIN_TEXTUAL_OUTPUT</literal> - or <literal>OUTPUT_PLUGIN_BINARY_OUTPUT</literal>. + or <literal>OUTPUT_PLUGIN_BINARY_OUTPUT</literal>. See also + <xref linkend="logicaldecoding-output-mode"/>. </para> <para> The startup callback should validate the options present in |