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diff --git a/doc/src/sgml/html/rules-status.html b/doc/src/sgml/html/rules-status.html new file mode 100644 index 0000000..570500f --- /dev/null +++ b/doc/src/sgml/html/rules-status.html @@ -0,0 +1,35 @@ +<?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>40.6. Rules and Command Status</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 V1.79.1" /><link rel="prev" href="rules-privileges.html" title="40.5. Rules and Privileges" /><link rel="next" href="rules-triggers.html" title="40.7. Rules Versus Triggers" /></head><body id="docContent" class="container-fluid col-10"><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">40.6. Rules and Command Status</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="rules-privileges.html" title="40.5. Rules and Privileges">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="rules.html" title="Chapter 40. The Rule System">Up</a></td><th width="60%" align="center">Chapter 40. The Rule System</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 13.4 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="rules-triggers.html" title="40.7. Rules Versus Triggers">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="RULES-STATUS"><div class="titlepage"><div><div><h2 class="title" style="clear: both">40.6. Rules and Command Status</h2></div></div></div><p> + The <span class="productname">PostgreSQL</span> server returns a command + status string, such as <code class="literal">INSERT 149592 1</code>, for each + command it receives. This is simple enough when there are no rules + involved, but what happens when the query is rewritten by rules? +</p><p> + Rules affect the command status as follows: + + </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> + If there is no unconditional <code class="literal">INSTEAD</code> rule for the query, then + the originally given query will be executed, and its command + status will be returned as usual. (But note that if there were + any conditional <code class="literal">INSTEAD</code> rules, the negation of their qualifications + will have been added to the original query. This might reduce the + number of rows it processes, and if so the reported status will + be affected.) + </p></li><li class="listitem"><p> + If there is any unconditional <code class="literal">INSTEAD</code> rule for the query, then + the original query will not be executed at all. In this case, + the server will return the command status for the last query + that was inserted by an <code class="literal">INSTEAD</code> rule (conditional or + unconditional) and is of the same command type + (<code class="command">INSERT</code>, <code class="command">UPDATE</code>, or + <code class="command">DELETE</code>) as the original query. If no query + meeting those requirements is added by any rule, then the + returned command status shows the original query type and + zeroes for the row-count and OID fields. + </p></li></ul></div><p> +</p><p> + The programmer can ensure that any desired <code class="literal">INSTEAD</code> rule is the one + that sets the command status in the second case, by giving it the + alphabetically last rule name among the active rules, so that it + gets applied last. +</p></div><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navfooter"><hr></hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="rules-privileges.html" title="40.5. Rules and Privileges">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="rules.html" title="Chapter 40. The Rule System">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="rules-triggers.html" title="40.7. Rules Versus Triggers">Next</a></td></tr><tr><td width="40%" align="left" valign="top">40.5. Rules and Privileges </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 13.4 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 40.7. Rules Versus Triggers</td></tr></table></div></body></html>
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