From ca41705da15ca588d55f3c2cc2106284911e53a1 Mon Sep 17 00:00:00 2001
From: Yugo Nagata <nagata@sraoss.co.jp>
Date: Mon, 1 Jul 2024 16:16:39 +0900
Subject: [PATCH v2] psql: Add leakproof field to \dAo+ meta-command results

This adds a field that shows whether the underlying function of an
operator associated with operator families is leak-proof.
It is useful for checking an index can be used with security_barrier
views or row-level security policies when the query's WHERE
clause contains an operator which is associated with the index.
---
 doc/src/sgml/planstats.sgml        |  2 ++
 doc/src/sgml/ref/psql-ref.sgml     |  3 +-
 doc/src/sgml/rules.sgml            | 10 ++++++
 src/bin/psql/describe.c            | 17 ++++++---
 src/test/regress/expected/psql.out | 55 ++++++++++++++++--------------
 src/test/regress/sql/psql.sql      |  2 +-
 6 files changed, 58 insertions(+), 31 deletions(-)

diff --git a/doc/src/sgml/planstats.sgml b/doc/src/sgml/planstats.sgml
index c7ec749d0a..45b0d2b765 100644
--- a/doc/src/sgml/planstats.sgml
+++ b/doc/src/sgml/planstats.sgml
@@ -729,6 +729,8 @@ EXPLAIN (ANALYZE, TIMING OFF) SELECT * FROM t WHERE a &lt;= 49 AND b &gt; 49;
    accurately, the function that the operator is based on).  If not, then the
    selectivity estimator will behave as if no statistics are available, and
    the planner will proceed with default or fall-back assumptions.
+   Use <xref linkend="app-psql"/>'s <command>\dAo+</command> command to list
+   operator families and tell which of their operators are marked as leak-proof.
   </para>
 
   <para>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 07419a3b92..4d55472929 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1363,7 +1363,8 @@ INSERT INTO tbl1 VALUES ($1, $2) \bind 'first value' 'second value' \g
         is specified, only members of operator families whose names match that
         pattern are listed.
         If <literal>+</literal> is appended to the command name, each operator
-        is listed with its sort operator family (if it is an ordering operator).
+        is listed with its sort operator family (if it is an ordering operator),
+        and whether it is leak-proof.
         </para>
         </listitem>
       </varlistentry>
diff --git a/doc/src/sgml/rules.sgml b/doc/src/sgml/rules.sgml
index 7a928bd7b9..3f0c26dad3 100644
--- a/doc/src/sgml/rules.sgml
+++ b/doc/src/sgml/rules.sgml
@@ -2167,6 +2167,16 @@ CREATE VIEW phone_number WITH (security_barrier) AS
     view's row filters.
 </para>
 
+<para>
+    For example, an index scan cannot be selected for queries with
+    <literal>security_barrier</literal> views or row-level security policies if an
+    operator used in the <literal>WHERE</literal> clause is associated with the
+    operator family of the index, but its underlying function is not marked
+    <literal>LEAKPROOF</literal>. Use <xref linkend="app-psql"/>'s
+    <command>\dAo+</command> command to list operator families and tell which of
+    their operators are marked as leak-proof.
+</para>
+
 <para>
     It is important to understand that even a view created with the
     <literal>security_barrier</literal> option is intended to be secure only
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 7c9a1f234c..d1b2910073 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -6882,7 +6882,7 @@ listOpFamilyOperators(const char *access_method_pattern,
 	printQueryOpt myopt = pset.popt;
 	bool		have_where = false;
 
-	static const bool translate_columns[] = {false, false, false, false, false, false};
+	static const bool translate_columns[] = {false, false, false, false, false, false, false};
 
 	initPQExpBuffer(&buf);
 
@@ -6910,8 +6910,15 @@ listOpFamilyOperators(const char *access_method_pattern,
 
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ", ofs.opfname AS \"%s\"\n",
-						  gettext_noop("Sort opfamily"));
+						  ", ofs.opfname AS \"%s\",\n"
+						  "  CASE\n"
+						  "    WHEN p.proleakproof THEN '%s'\n"
+						  "    ELSE '%s'\n"
+						  "  END AS \"%s\"\n",
+						  gettext_noop("Sort opfamily"),
+						  gettext_noop("yes"),
+						  gettext_noop("no"),
+						  gettext_noop("Leak-proof"));
 	appendPQExpBufferStr(&buf,
 						 "FROM pg_catalog.pg_amop o\n"
 						 "  LEFT JOIN pg_catalog.pg_opfamily of ON of.oid = o.amopfamily\n"
@@ -6919,7 +6926,9 @@ listOpFamilyOperators(const char *access_method_pattern,
 						 "  LEFT JOIN pg_catalog.pg_namespace nsf ON of.opfnamespace = nsf.oid\n");
 	if (verbose)
 		appendPQExpBufferStr(&buf,
-							 "  LEFT JOIN pg_catalog.pg_opfamily ofs ON ofs.oid = o.amopsortfamily\n");
+							 "  LEFT JOIN pg_catalog.pg_opfamily ofs ON ofs.oid = o.amopsortfamily\n"
+							 "  LEFT JOIN pg_catalog.pg_operator op ON op.oid = o.amopopr\n"
+							 "  LEFT JOIN pg_catalog.pg_proc p ON p.oid = op.oprcode\n");
 
 	if (access_method_pattern)
 	{
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 3bbe4c5f97..7632f252c6 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -5082,31 +5082,36 @@ List of access methods
  btree | integer_ops     | smallint, integer, bigint
 (1 row)
 
-\dAo+ btree float_ops
-                                List of operators of operator families
-  AM   | Operator family |               Operator                | Strategy | Purpose | Sort opfamily 
--------+-----------------+---------------------------------------+----------+---------+---------------
- btree | float_ops       | <(double precision,double precision)  |        1 | search  | 
- btree | float_ops       | <=(double precision,double precision) |        2 | search  | 
- btree | float_ops       | =(double precision,double precision)  |        3 | search  | 
- btree | float_ops       | >=(double precision,double precision) |        4 | search  | 
- btree | float_ops       | >(double precision,double precision)  |        5 | search  | 
- btree | float_ops       | <(real,real)                          |        1 | search  | 
- btree | float_ops       | <=(real,real)                         |        2 | search  | 
- btree | float_ops       | =(real,real)                          |        3 | search  | 
- btree | float_ops       | >=(real,real)                         |        4 | search  | 
- btree | float_ops       | >(real,real)                          |        5 | search  | 
- btree | float_ops       | <(double precision,real)              |        1 | search  | 
- btree | float_ops       | <=(double precision,real)             |        2 | search  | 
- btree | float_ops       | =(double precision,real)              |        3 | search  | 
- btree | float_ops       | >=(double precision,real)             |        4 | search  | 
- btree | float_ops       | >(double precision,real)              |        5 | search  | 
- btree | float_ops       | <(real,double precision)              |        1 | search  | 
- btree | float_ops       | <=(real,double precision)             |        2 | search  | 
- btree | float_ops       | =(real,double precision)              |        3 | search  | 
- btree | float_ops       | >=(real,double precision)             |        4 | search  | 
- btree | float_ops       | >(real,double precision)              |        5 | search  | 
-(20 rows)
+\dAo+ btree array_ops|float_ops
+                                      List of operators of operator families
+  AM   | Operator family |               Operator                | Strategy | Purpose | Sort opfamily | Leak-proof 
+-------+-----------------+---------------------------------------+----------+---------+---------------+------------
+ btree | array_ops       | <(anyarray,anyarray)                  |        1 | search  |               | no
+ btree | array_ops       | <=(anyarray,anyarray)                 |        2 | search  |               | no
+ btree | array_ops       | =(anyarray,anyarray)                  |        3 | search  |               | no
+ btree | array_ops       | >=(anyarray,anyarray)                 |        4 | search  |               | no
+ btree | array_ops       | >(anyarray,anyarray)                  |        5 | search  |               | no
+ btree | float_ops       | <(double precision,double precision)  |        1 | search  |               | yes
+ btree | float_ops       | <=(double precision,double precision) |        2 | search  |               | yes
+ btree | float_ops       | =(double precision,double precision)  |        3 | search  |               | yes
+ btree | float_ops       | >=(double precision,double precision) |        4 | search  |               | yes
+ btree | float_ops       | >(double precision,double precision)  |        5 | search  |               | yes
+ btree | float_ops       | <(real,real)                          |        1 | search  |               | yes
+ btree | float_ops       | <=(real,real)                         |        2 | search  |               | yes
+ btree | float_ops       | =(real,real)                          |        3 | search  |               | yes
+ btree | float_ops       | >=(real,real)                         |        4 | search  |               | yes
+ btree | float_ops       | >(real,real)                          |        5 | search  |               | yes
+ btree | float_ops       | <(double precision,real)              |        1 | search  |               | yes
+ btree | float_ops       | <=(double precision,real)             |        2 | search  |               | yes
+ btree | float_ops       | =(double precision,real)              |        3 | search  |               | yes
+ btree | float_ops       | >=(double precision,real)             |        4 | search  |               | yes
+ btree | float_ops       | >(double precision,real)              |        5 | search  |               | yes
+ btree | float_ops       | <(real,double precision)              |        1 | search  |               | yes
+ btree | float_ops       | <=(real,double precision)             |        2 | search  |               | yes
+ btree | float_ops       | =(real,double precision)              |        3 | search  |               | yes
+ btree | float_ops       | >=(real,double precision)             |        4 | search  |               | yes
+ btree | float_ops       | >(real,double precision)              |        5 | search  |               | yes
+(25 rows)
 
 \dAo * pg_catalog.jsonb_path_ops
              List of operators of operator families
diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql
index 3b3c6f6e29..d59eae1814 100644
--- a/src/test/regress/sql/psql.sql
+++ b/src/test/regress/sql/psql.sql
@@ -1266,7 +1266,7 @@ drop role regress_partitioning_role;
 \dAc brin pg*.oid*
 \dAf spgist
 \dAf btree int4
-\dAo+ btree float_ops
+\dAo+ btree array_ops|float_ops
 \dAo * pg_catalog.jsonb_path_ops
 \dAp+ btree float_ops
 \dAp * pg_catalog.uuid_ops
-- 
2.34.1

