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diff --git a/doc/src/sgml/html/sql-createforeigndatawrapper.html b/doc/src/sgml/html/sql-createforeigndatawrapper.html new file mode 100644 index 0000000..d45b8df --- /dev/null +++ b/doc/src/sgml/html/sql-createforeigndatawrapper.html @@ -0,0 +1,77 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>CREATE FOREIGN DATA WRAPPER</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="sql-createextension.html" title="CREATE EXTENSION" /><link rel="next" href="sql-createforeigntable.html" title="CREATE FOREIGN TABLE" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">CREATE FOREIGN DATA WRAPPER</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="sql-createextension.html" title="CREATE EXTENSION">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="sql-commands.html" title="SQL Commands">Up</a></td><th width="60%" align="center">SQL Commands</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 15.4 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="sql-createforeigntable.html" title="CREATE FOREIGN TABLE">Next</a></td></tr></table><hr /></div><div class="refentry" id="SQL-CREATEFOREIGNDATAWRAPPER"><div class="titlepage"></div><a id="id-1.9.3.65.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle">CREATE FOREIGN DATA WRAPPER</span></h2><p>CREATE FOREIGN DATA WRAPPER — define a new foreign-data wrapper</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis"> +CREATE FOREIGN DATA WRAPPER <em class="replaceable"><code>name</code></em> + [ HANDLER <em class="replaceable"><code>handler_function</code></em> | NO HANDLER ] + [ VALIDATOR <em class="replaceable"><code>validator_function</code></em> | NO VALIDATOR ] + [ OPTIONS ( <em class="replaceable"><code>option</code></em> '<em class="replaceable"><code>value</code></em>' [, ... ] ) ] +</pre></div><div class="refsect1" id="id-1.9.3.65.5"><h2>Description</h2><p> + <code class="command">CREATE FOREIGN DATA WRAPPER</code> creates a new + foreign-data wrapper. The user who defines a foreign-data wrapper + becomes its owner. + </p><p> + The foreign-data wrapper name must be unique within the database. + </p><p> + Only superusers can create foreign-data wrappers. + </p></div><div class="refsect1" id="id-1.9.3.65.6"><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="replaceable"><code>name</code></em></span></dt><dd><p> + The name of the foreign-data wrapper to be created. + </p></dd><dt><span class="term"><code class="literal">HANDLER <em class="replaceable"><code>handler_function</code></em></code></span></dt><dd><p><em class="replaceable"><code>handler_function</code></em> is the + name of a previously registered function that will be called to + retrieve the execution functions for foreign tables. + The handler function must take no arguments, and + its return type must be <code class="type">fdw_handler</code>. + </p><p> + It is possible to create a foreign-data wrapper with no handler + function, but foreign tables using such a wrapper can only be declared, + not accessed. + </p></dd><dt><span class="term"><code class="literal">VALIDATOR <em class="replaceable"><code>validator_function</code></em></code></span></dt><dd><p><em class="replaceable"><code>validator_function</code></em> + is the name of a previously registered function that will be called to + check the generic options given to the foreign-data wrapper, as + well as options for foreign servers, user mappings and foreign tables + using the foreign-data wrapper. If no validator function or <code class="literal">NO + VALIDATOR</code> is specified, then options will not be + checked at creation time. (Foreign-data wrappers will possibly + ignore or reject invalid option specifications at run time, + depending on the implementation.) The validator function must + take two arguments: one of type <code class="type">text[]</code>, which will + contain the array of options as stored in the system catalogs, + and one of type <code class="type">oid</code>, which will be the OID of the + system catalog containing the options. The return type is ignored; + the function should report invalid options using the + <code class="function">ereport(ERROR)</code> function. + </p></dd><dt><span class="term"><code class="literal">OPTIONS ( <em class="replaceable"><code>option</code></em> '<em class="replaceable"><code>value</code></em>' [, ... ] )</code></span></dt><dd><p> + This clause specifies options for the new foreign-data wrapper. + The allowed option names and values are specific to each foreign + data wrapper and are validated using the foreign-data wrapper's + validator function. Option names must be unique. + </p></dd></dl></div></div><div class="refsect1" id="id-1.9.3.65.7"><h2>Notes</h2><p> + <span class="productname">PostgreSQL</span>'s foreign-data functionality is still under + active development. Optimization of queries is primitive (and mostly left + to the wrapper, too). Thus, there is considerable room for future + performance improvements. + </p></div><div class="refsect1" id="id-1.9.3.65.8"><h2>Examples</h2><p> + Create a useless foreign-data wrapper <code class="literal">dummy</code>: +</p><pre class="programlisting"> +CREATE FOREIGN DATA WRAPPER dummy; +</pre><p> + </p><p> + Create a foreign-data wrapper <code class="literal">file</code> with + handler function <code class="literal">file_fdw_handler</code>: +</p><pre class="programlisting"> +CREATE FOREIGN DATA WRAPPER file HANDLER file_fdw_handler; +</pre><p> + </p><p> + Create a foreign-data wrapper <code class="literal">mywrapper</code> with some + options: +</p><pre class="programlisting"> +CREATE FOREIGN DATA WRAPPER mywrapper + OPTIONS (debug 'true'); +</pre></div><div class="refsect1" id="id-1.9.3.65.9"><h2>Compatibility</h2><p> + <code class="command">CREATE FOREIGN DATA WRAPPER</code> conforms to ISO/IEC + 9075-9 (SQL/MED), with the exception that the <code class="literal">HANDLER</code> + and <code class="literal">VALIDATOR</code> clauses are extensions and the standard + clauses <code class="literal">LIBRARY</code> and <code class="literal">LANGUAGE</code> + are not implemented in <span class="productname">PostgreSQL</span>. + </p><p> + Note, however, that the SQL/MED functionality as a whole is not yet + conforming. + </p></div><div class="refsect1" id="id-1.9.3.65.10"><h2>See Also</h2><span class="simplelist"><a class="xref" href="sql-alterforeigndatawrapper.html" title="ALTER FOREIGN DATA WRAPPER"><span class="refentrytitle">ALTER FOREIGN DATA WRAPPER</span></a>, <a class="xref" href="sql-dropforeigndatawrapper.html" title="DROP FOREIGN DATA WRAPPER"><span class="refentrytitle">DROP FOREIGN DATA WRAPPER</span></a>, <a class="xref" href="sql-createserver.html" title="CREATE SERVER"><span class="refentrytitle">CREATE SERVER</span></a>, <a class="xref" href="sql-createusermapping.html" title="CREATE USER MAPPING"><span class="refentrytitle">CREATE USER MAPPING</span></a>, <a class="xref" href="sql-createforeigntable.html" title="CREATE FOREIGN TABLE"><span class="refentrytitle">CREATE FOREIGN TABLE</span></a></span></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="sql-createextension.html" title="CREATE EXTENSION">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="sql-commands.html" title="SQL Commands">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="sql-createforeigntable.html" title="CREATE FOREIGN TABLE">Next</a></td></tr><tr><td width="40%" align="left" valign="top">CREATE EXTENSION </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 15.4 Documentation">Home</a></td><td width="40%" align="right" valign="top"> CREATE FOREIGN TABLE</td></tr></table></div></body></html>
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