Date: Fri, 18 Dec 2020 11:33:12 -0600
From: Justin Pryzby <pryzby@telsasoft.com>
To: Laurenz Albe <laurenz.albe@cybertec.at>
Cc: pgsql-hackers@postgresql.org
Subject: Re: allow to \dtS+ pg_toast.*
Message-ID: <20201218173312.GZ30237@telsasoft.com>
References: <20201130165436.GX24052@telsasoft.com>
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On Fri, Dec 18, 2020 at 12:43:07PM +0100, Laurenz Albe wrote:
> On Fri, 2020-12-18 at 00:58 -0600, Justin Pryzby wrote:
> > On Thu, Dec 17, 2020 at 04:16:52PM +0100, Laurenz Albe wrote:
> > > On Mon, 2020-11-30 at 10:54 -0600, Justin Pryzby wrote:
> > > > This makes toast tables a bit less special and easier to inspect.
> > > > 
> > > > postgres=# \dtS+ pg_toast.pg_toast_2619
> > > >  pg_toast | pg_toast_2619 | toast table | pryzbyj | permanent   | heap          | 56 kB | 
> > > > 
> > > > This follows commit from last year:
> > > > | eb5472da9 make \d pg_toast.foo show its indices ; and, \d toast show its main table
> > > 
> > > This would indeed be convenient.
> > > 
> > > While playing around with it, I found the following oddity:
> > > 
> > > regression=# \dtS pg_toast.pg_toast_30701
> > >  pg_toast | pg_toast_30701 | toast table | laurenz
> > > 
> > > regression=# \dt pg_toast.pg_toast_30701
> > > Did not find any relation named "pg_toast.pg_toast_30701".
> > > 
> > > Now this doesn't seem right.  To my understanding, \dtS should do the same as \dt,
> > > except that it should also search in "pg_catalog" if no schema was provided.
> > 
> > You mean that if pg_toast.* should be shown if a matching "pattern" is given,
> > even if "S" was not used.  I think you're right.  The behavior I implemented
> > was intended to provide a bit of historic compatibility towards hiding toast
> > tables, but I think it's not needed, since they're not shown anyway unless
> > someone includes "S", specifies the "pg_toast." schema, or pg_toast is in their
> > search path.  See attached.
> 
> Yes, exactly.
> 
> I wonder why the modification in "listPartitionedTables" is necessary.
> Surely there cannot be any partitioned toast tables, can there?

The comment should be removed for consistency.
And I changed the code for consistency with listTables (from which I assume
listPartitionedTables was derived - I was involved in the last stages of that
patch).  It doesn't need to exclude pg_catalog or information_schema, either,
but it's kept the same for consistency.  That part could also be removed.

> > > Another thing that is missing is tab completion for
> > > regression=# \dtS pg_toast.pg_
> > > This should work just like for \d and \dS.
..
> If I want to know how big the TOAST table of relation 87654 is,
> I think it is convenient if I can tab to
> 
> \dt+ pg_toast.pg_toast_

I agree that it's nice to complete the schema name, but I'm still not convinced
this part should be included.

The way to include pg_toast.pg_toast is if toast relations are included, which
is exactly what Tom pointed out is usually unhelpful.  If you include toast
relations, tab completion might give "pg_toast.pg_toast_14..." when you wanted
to paste "145678" - you'd need to remove the common suffix that it found.

I considered whether "toast table" should be capitalized (as it is for "\d")
but I think it should stay lowercase.

-- 
Justin

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From 987bbcb083507426018bfccd1eae7552468c57cb Mon Sep 17 00:00:00 2001
From: Justin Pryzby <pryzbyj@telsasoft.com>
Date: Wed, 28 Oct 2020 23:51:39 -0500
Subject: [PATCH] Allow to \dti+ pg_toast.*

This reverts commit 81fc5df83.  Rather than being consistent by hiding toast
tables, instead allow toast tables to be displayed by specifying "S", or their
schema, or by including pg_toast in search_path.
---
 src/bin/psql/describe.c     | 24 ++++++------------------
 src/bin/psql/tab-complete.c | 13 ++++++++++++-
 2 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 8923eee752..b7a8bd4121 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -3762,6 +3762,7 @@ listTables(const char *tabtypes, const char *pattern, bool verbose, bool showSys
 					  " WHEN " CppAsString2(RELKIND_INDEX) " THEN '%s'"
 					  " WHEN " CppAsString2(RELKIND_SEQUENCE) " THEN '%s'"
 					  " WHEN 's' THEN '%s'"
+					  " WHEN " CppAsString2(RELKIND_TOASTVALUE) " THEN '%s'"
 					  " WHEN " CppAsString2(RELKIND_FOREIGN_TABLE) " THEN '%s'"
 					  " WHEN " CppAsString2(RELKIND_PARTITIONED_TABLE) " THEN '%s'"
 					  " WHEN " CppAsString2(RELKIND_PARTITIONED_INDEX) " THEN '%s'"
@@ -3775,6 +3776,7 @@ listTables(const char *tabtypes, const char *pattern, bool verbose, bool showSys
 					  gettext_noop("index"),
 					  gettext_noop("sequence"),
 					  gettext_noop("special"),
+					  gettext_noop("toast table"),
 					  gettext_noop("foreign table"),
 					  gettext_noop("partitioned table"),
 					  gettext_noop("partitioned index"),
@@ -3870,6 +3872,8 @@ listTables(const char *tabtypes, const char *pattern, bool verbose, bool showSys
 		appendPQExpBufferStr(&buf, CppAsString2(RELKIND_SEQUENCE) ",");
 	if (showSystem || pattern)
 		appendPQExpBufferStr(&buf, "'s',"); /* was RELKIND_SPECIAL */
+	if ((showSystem || pattern) && showTables)
+		appendPQExpBufferStr(&buf, "'t',"); /* toast tables */
 	if (showForeign)
 		appendPQExpBufferStr(&buf, CppAsString2(RELKIND_FOREIGN_TABLE) ",");
 
@@ -3878,17 +3882,9 @@ listTables(const char *tabtypes, const char *pattern, bool verbose, bool showSys
 
 	if (!showSystem && !pattern)
 		appendPQExpBufferStr(&buf, "      AND n.nspname <> 'pg_catalog'\n"
+							 "      AND n.nspname !~ '^pg_toast'\n"
 							 "      AND n.nspname <> 'information_schema'\n");
 
-	/*
-	 * TOAST objects are suppressed unconditionally.  Since we don't provide
-	 * any way to select RELKIND_TOASTVALUE above, we would never show toast
-	 * tables in any case; it seems a bit confusing to allow their indexes to
-	 * be shown.  Use plain \d if you really need to look at a TOAST
-	 * table/index.
-	 */
-	appendPQExpBufferStr(&buf, "      AND n.nspname !~ '^pg_toast'\n");
-
 	processSQLNamePattern(pset.db, &buf, pattern, true, false,
 						  "n.nspname", "c.relname", NULL,
 						  "pg_catalog.pg_table_is_visible(c.oid)");
@@ -4101,17 +4097,9 @@ listPartitionedTables(const char *reltypes, const char *pattern, bool verbose)
 
 	if (!pattern)
 		appendPQExpBufferStr(&buf, "      AND n.nspname <> 'pg_catalog'\n"
+							 "      AND n.nspname !~ '^pg_toast'\n"
 							 "      AND n.nspname <> 'information_schema'\n");
 
-	/*
-	 * TOAST objects are suppressed unconditionally.  Since we don't provide
-	 * any way to select RELKIND_TOASTVALUE above, we would never show toast
-	 * tables in any case; it seems a bit confusing to allow their indexes to
-	 * be shown.  Use plain \d if you really need to look at a TOAST
-	 * table/index.
-	 */
-	appendPQExpBufferStr(&buf, "      AND n.nspname !~ '^pg_toast'\n");
-
 	processSQLNamePattern(pset.db, &buf, pattern, true, false,
 						  "n.nspname", "c.relname", NULL,
 						  "pg_catalog.pg_table_is_visible(c.oid)");
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 8d6f93147e..58b4d55a96 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -453,6 +453,17 @@ static const SchemaQuery Query_for_list_of_tables = {
 	.result = "pg_catalog.quote_ident(c.relname)",
 };
 
+static const SchemaQuery Query_for_list_of_tables_with_toast = {
+	.catname = "pg_catalog.pg_class c",
+	.selcondition =
+	"c.relkind IN (" CppAsString2(RELKIND_RELATION) ", "
+	CppAsString2(RELKIND_TOASTVALUE) ", "
+	CppAsString2(RELKIND_PARTITIONED_TABLE) ")",
+	.viscondition = "pg_catalog.pg_table_is_visible(c.oid)",
+	.namespace = "c.relnamespace",
+	.result = "pg_catalog.quote_ident(c.relname)",
+};
+
 static const SchemaQuery Query_for_list_of_partitioned_tables = {
 	.catname = "pg_catalog.pg_class c",
 	.selcondition = "c.relkind IN (" CppAsString2(RELKIND_PARTITIONED_TABLE) ")",
@@ -3903,7 +3914,7 @@ psql_completion(const char *text, int start, int end)
 	else if (TailMatchesCS("\\ds*"))
 		COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_sequences, NULL);
 	else if (TailMatchesCS("\\dt*"))
-		COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_tables, NULL);
+		COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_tables_with_toast, NULL);
 	else if (TailMatchesCS("\\dT*"))
 		COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes, NULL);
 	else if (TailMatchesCS("\\du*") || TailMatchesCS("\\dg*"))
-- 
2.17.0


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