From fe604800681aed8228fbe67d2e175d6822c66ea2 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 23 Mar 2020 12:42:15 -0400
Subject: [PATCH] Doc: explain that LIKE et al can be used in ANY (sub-select)
 etc.

This wasn't stated anywhere, and it's perhaps not that obvious,
since we get questions about it from time to time.  Also undocumented
was that the parser actually translates these into operators.

Discussion: https://postgr.es/m/CAFj8pRBkvZ71BqGKZnBBG4=0cKG+s50Dy+DYmrizUKEpAtdc+w@mail.gmail.com
---
 doc/src/sgml/func.sgml | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 464a48ed6af..0057a177570 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -3565,7 +3565,23 @@ cast(-44 as bit(12))           <lineannotation>111111010100</lineannotation>
     <literal>!~~</literal> and <literal>!~~*</literal> operators that
     represent <function>NOT LIKE</function> and <function>NOT
     ILIKE</function>, respectively.  All of these operators are
-    <productname>PostgreSQL</productname>-specific.
+    <productname>PostgreSQL</productname>-specific.  You may see these
+    operator names in <command>EXPLAIN</command> output and similar
+    places, since the parser actually translates <function>LIKE</function>
+    et al. to these operators.
+   </para>
+
+   <para>
+    The phrases <function>LIKE</function>, <function>ILIKE</function>,
+    <function>NOT LIKE</function>, and <function>NOT ILIKE</function> are
+    generally treated as operators
+    in <productname>PostgreSQL</productname> syntax; for example they can
+    be used in <replaceable>expression</replaceable>
+    <replaceable>operator</replaceable> ANY
+    (<replaceable>subquery</replaceable>) constructs, although
+    an <literal>ESCAPE</literal> clause cannot be included there.  In some
+    obscure cases it may be necessary to use the underlying operator names
+    instead.
    </para>
 
    <para>