On Wed, Oct 30, 2024 at 7:32 PM Rafia Sabih <rafia.pghack...@gmail.com> wrote:
> Good catch. I agree with this being an unwarranted behaviour.
> A minor comment from my end is the wording of the error message.
> Based on the Postgresql error message style huide, something like this could
> be better,
> "could not access temporary relations of other sessions".
> --
> Regards,
> Rafia Sabih
> CYBERTEC PostgreSQL International GmbH
>
Thanks for your comment. I attach a patch with a fixed error message.
Also you can find it in commit fest
(https://commitfest.postgresql.org/51/5379/)
--
Best Regards,
Daniil Davydov
From 2c2e1b2fd75d38d43fbec5023691b93dceb18dbb Mon Sep 17 00:00:00 2001
From: Daniil Davidov <davydovdaniil...@gmail.com>
Date: Sun, 27 Oct 2024 16:15:50 +0700
Subject: [PATCH] Add fixes so now we cannot access to temporary tables of
other sessions
---
src/backend/catalog/namespace.c | 52 ++++------
src/backend/nodes/makefuncs.c | 6 +-
src/backend/parser/gram.y | 11 ++-
src/test/isolation/expected/temp-tables.out | 92 +++++++++++++++++
src/test/isolation/isolation_schedule | 1 +
src/test/isolation/specs/temp-tables.spec | 103 ++++++++++++++++++++
6 files changed, 231 insertions(+), 34 deletions(-)
create mode 100644 src/test/isolation/expected/temp-tables.out
create mode 100644 src/test/isolation/specs/temp-tables.spec
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index 30807f9190..1a8e8c8844 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -499,28 +499,19 @@ RangeVarGetRelidExtended(const RangeVar *relation, LOCKMODE lockmode,
*/
if (relation->relpersistence == RELPERSISTENCE_TEMP)
{
- if (!OidIsValid(myTempNamespace))
- relId = InvalidOid; /* this probably can't happen? */
- else
+ if (relation->schemaname)
{
- if (relation->schemaname)
- {
- Oid namespaceId;
+ Oid namespaceId;
- namespaceId = LookupExplicitNamespace(relation->schemaname, missing_ok);
-
- /*
- * For missing_ok, allow a non-existent schema name to
- * return InvalidOid.
- */
- if (namespaceId != myTempNamespace)
- ereport(ERROR,
- (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
- errmsg("temporary tables cannot specify a schema name")));
- }
-
- relId = get_relname_relid(relation->relname, myTempNamespace);
+ namespaceId = LookupExplicitNamespace(relation->schemaname,
+ missing_ok);
+ if (namespaceId != myTempNamespace)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("could not access temporary relations of other sessions")));
}
+
+ relId = get_relname_relid(relation->relname, myTempNamespace);
}
else if (relation->schemaname)
{
@@ -3387,17 +3378,14 @@ LookupExplicitNamespace(const char *nspname, bool missing_ok)
Oid namespaceId;
AclResult aclresult;
- /* check for pg_temp alias */
if (strcmp(nspname, "pg_temp") == 0)
{
- if (OidIsValid(myTempNamespace))
- return myTempNamespace;
-
/*
- * Since this is used only for looking up existing objects, there is
- * no point in trying to initialize the temp namespace here; and doing
- * so might create problems for some callers --- just fall through.
+ * If namespace specified in 'pg_temp' format
+ * (without owner proc number specification), we assume that this is
+ * our temporary namespace
*/
+ return myTempNamespace;
}
namespaceId = get_namespace_oid(nspname, missing_ok);
@@ -3553,21 +3541,19 @@ get_namespace_oid(const char *nspname, bool missing_ok)
RangeVar *
makeRangeVarFromNameList(const List *names)
{
- RangeVar *rel = makeRangeVar(NULL, NULL, -1);
+ RangeVar *rel;
switch (list_length(names))
{
case 1:
- rel->relname = strVal(linitial(names));
+ rel = makeRangeVar(NULL, strVal(linitial(names)), -1);
break;
case 2:
- rel->schemaname = strVal(linitial(names));
- rel->relname = strVal(lsecond(names));
+ rel = makeRangeVar(strVal(linitial(names)), strVal(lsecond(names)), -1);
break;
case 3:
+ rel = makeRangeVar(strVal(lsecond(names)), strVal(lthird(names)), -1);
rel->catalogname = strVal(linitial(names));
- rel->schemaname = strVal(lsecond(names));
- rel->relname = strVal(lthird(names));
break;
default:
ereport(ERROR,
@@ -3774,6 +3760,8 @@ GetTempNamespaceProcNumber(Oid namespaceId)
return INVALID_PROC_NUMBER; /* no such namespace? */
if (strncmp(nspname, "pg_temp_", 8) == 0)
result = atoi(nspname + 8);
+ else if (strncmp(nspname, "pg_temp", 7) == 0)
+ result = MyProcNumber;
else if (strncmp(nspname, "pg_toast_temp_", 14) == 0)
result = atoi(nspname + 14);
else
diff --git a/src/backend/nodes/makefuncs.c b/src/backend/nodes/makefuncs.c
index 61ac172a85..e60044c9d5 100644
--- a/src/backend/nodes/makefuncs.c
+++ b/src/backend/nodes/makefuncs.c
@@ -429,10 +429,14 @@ makeRangeVar(char *schemaname, char *relname, int location)
r->schemaname = schemaname;
r->relname = relname;
r->inh = true;
- r->relpersistence = RELPERSISTENCE_PERMANENT;
r->alias = NULL;
r->location = location;
+ if (r->schemaname && strncmp(r->schemaname, "pg_temp", 7) == 0)
+ r->relpersistence = RELPERSISTENCE_TEMP;
+ else
+ r->relpersistence = RELPERSISTENCE_PERMANENT;
+
return r;
}
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index bca627c546..02c13fdd16 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -19184,7 +19184,11 @@ makeRangeVarFromAnyName(List *names, int position, core_yyscan_t yyscanner)
break;
}
- r->relpersistence = RELPERSISTENCE_PERMANENT;
+ if (r->schemaname && strncmp(r->schemaname, "pg_temp", 7) == 0)
+ r->relpersistence = RELPERSISTENCE_TEMP;
+ else
+ r->relpersistence = RELPERSISTENCE_PERMANENT;
+
r->location = position;
return r;
@@ -19224,6 +19228,11 @@ makeRangeVarFromQualifiedName(char *name, List *namelist, int location,
break;
}
+ if (r->schemaname && strncmp(r->schemaname, "pg_temp", 7) == 0)
+ r->relpersistence = RELPERSISTENCE_TEMP;
+ else
+ r->relpersistence = RELPERSISTENCE_PERMANENT;
+
return r;
}
diff --git a/src/test/isolation/expected/temp-tables.out b/src/test/isolation/expected/temp-tables.out
new file mode 100644
index 0000000000..328e7d34b9
--- /dev/null
+++ b/src/test/isolation/expected/temp-tables.out
@@ -0,0 +1,92 @@
+Parsed test spec with 2 sessions
+
+starting permutation: s1_st1 s1_st2 s2_st1
+step s1_st1: CREATE TEMP TABLE test_tmp(id int);
+step s1_st2: INSERT INTO temp_schema_id SELECT pg_my_temp_schema();
+s2: NOTICE: cannot access temporary tables of other sessions
+s2: NOTICE: cannot access temporary tables of other sessions
+s2: NOTICE: cannot access temporary tables of other sessions
+s2: NOTICE: cannot access temporary tables of other sessions
+s2: NOTICE: cannot access temporary tables of other sessions
+s2: NOTICE: cannot access temporary tables of other sessions
+s2: NOTICE: cannot access temporary tables of other sessions
+step s2_st1:
+ DO $$
+ DECLARE
+ schema_name text;
+ result RECORD;
+ BEGIN
+ -- Find out name of temporary schema of first session
+ SELECT nspname INTO schema_name
+ FROM pg_namespace
+ WHERE oid = (SELECT oid FROM temp_schema_id LIMIT 1);
+
+ -- Both INSERT operation must fail due to 'cannot access temporary
+ -- tables of other sessions' error
+ BEGIN
+ EXECUTE format('INSERT INTO %I.test_tmp VALUES (1);', schema_name);
+ EXCEPTION
+ WHEN feature_not_supported
+ THEN RAISE NOTICE 'cannot access temporary tables of other sessions';
+ END;
+
+ BEGIN
+ EXECUTE format('INSERT INTO %I.test_tmp VALUES (2);', schema_name);
+ EXCEPTION
+ WHEN feature_not_supported
+ THEN RAISE NOTICE 'cannot access temporary tables of other sessions';
+ END;
+
+ -- SELECT operation must fail due to 'cannot access temporary tables
+ -- of other sessions' error
+ BEGIN
+ FOR result IN
+ EXECUTE format('SELECT * FROM %I.test_tmp;', schema_name) LOOP
+ RAISE NOTICE '%', result;
+ END LOOP;
+ EXCEPTION
+ WHEN feature_not_supported
+ THEN RAISE NOTICE 'cannot access temporary tables of other sessions';
+ END;
+
+ -- UPDATE operation must fail due to 'cannot access temporary tables
+ -- of other sessions' error
+ BEGIN
+ EXECUTE format('UPDATE %I.test_tmp SET id = 100 WHERE id = 3;', schema_name);
+ EXCEPTION
+ WHEN feature_not_supported
+ THEN RAISE NOTICE 'cannot access temporary tables of other sessions';
+ END;
+
+ -- DELETE operation must fail due to 'cannot access temporary tables
+ -- of other sessions' error
+ BEGIN
+ EXECUTE format('DELETE FROM %I.test_tmp WHERE id = 3;', schema_name);
+ EXCEPTION
+ WHEN feature_not_supported
+ THEN RAISE NOTICE 'cannot access temporary tables of other sessions';
+ END;
+
+ -- LOCK operation must fail due to 'cannot access temporary tables
+ -- of other sessions' error
+ BEGIN
+ EXECUTE format('BEGIN;
+ LOCK TABLE %I.test_tmp;
+ COMMIT;',
+ schema_name);
+ EXCEPTION
+ WHEN feature_not_supported
+ THEN RAISE NOTICE 'cannot access temporary tables of other sessions';
+ END;
+
+ -- DROP operation must fail due to 'cannot access temporary tables
+ -- of other sessions' error
+ BEGIN
+ EXECUTE format('DROP TABLE %I.test_tmp;', schema_name);
+ EXCEPTION
+ WHEN feature_not_supported
+ THEN RAISE NOTICE 'cannot access temporary tables of other sessions';
+ END;
+ END
+ $$;
+
diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule
index 143109aa4d..8ed3f821a4 100644
--- a/src/test/isolation/isolation_schedule
+++ b/src/test/isolation/isolation_schedule
@@ -115,3 +115,4 @@ test: serializable-parallel-2
test: serializable-parallel-3
test: matview-write-skew
test: lock-nowait
+test: temp-tables
\ No newline at end of file
diff --git a/src/test/isolation/specs/temp-tables.spec b/src/test/isolation/specs/temp-tables.spec
new file mode 100644
index 0000000000..009bd9845b
--- /dev/null
+++ b/src/test/isolation/specs/temp-tables.spec
@@ -0,0 +1,103 @@
+# Test access to temporary tables of other sessions
+
+# We need to know oid of first session's temporary schema
+setup { CREATE TABLE temp_schema_id(oid oid); }
+
+teardown { DROP TABLE temp_schema_id; }
+
+session s1
+
+# In first session we only need to create temporary table and "remember" its oid
+step s1_st1 { CREATE TEMP TABLE test_tmp(id int); }
+step s1_st2 { INSERT INTO temp_schema_id SELECT pg_my_temp_schema(); }
+
+session s2
+
+# In this DO block we will try to access to temp table created before via
+# INSERT/UPDATE/DELETE/SELECT/TRUNCATE/LOCK operations
+step s2_st1
+{
+ DO $$
+ DECLARE
+ schema_name text;
+ result RECORD;
+ BEGIN
+ -- Find out name of temporary schema of first session
+ SELECT nspname INTO schema_name
+ FROM pg_namespace
+ WHERE oid = (SELECT oid FROM temp_schema_id LIMIT 1);
+
+ -- Both INSERT operation must fail due to 'cannot access temporary
+ -- tables of other sessions' error
+ BEGIN
+ EXECUTE format('INSERT INTO %I.test_tmp VALUES (1);', schema_name);
+ EXCEPTION
+ WHEN feature_not_supported
+ THEN RAISE NOTICE 'cannot access temporary tables of other sessions';
+ END;
+
+ BEGIN
+ EXECUTE format('INSERT INTO %I.test_tmp VALUES (2);', schema_name);
+ EXCEPTION
+ WHEN feature_not_supported
+ THEN RAISE NOTICE 'cannot access temporary tables of other sessions';
+ END;
+
+ -- SELECT operation must fail due to 'cannot access temporary tables
+ -- of other sessions' error
+ BEGIN
+ FOR result IN
+ EXECUTE format('SELECT * FROM %I.test_tmp;', schema_name) LOOP
+ RAISE NOTICE '%', result;
+ END LOOP;
+ EXCEPTION
+ WHEN feature_not_supported
+ THEN RAISE NOTICE 'cannot access temporary tables of other sessions';
+ END;
+
+ -- UPDATE operation must fail due to 'cannot access temporary tables
+ -- of other sessions' error
+ BEGIN
+ EXECUTE format('UPDATE %I.test_tmp SET id = 100 WHERE id = 3;', schema_name);
+ EXCEPTION
+ WHEN feature_not_supported
+ THEN RAISE NOTICE 'cannot access temporary tables of other sessions';
+ END;
+
+ -- DELETE operation must fail due to 'cannot access temporary tables
+ -- of other sessions' error
+ BEGIN
+ EXECUTE format('DELETE FROM %I.test_tmp WHERE id = 3;', schema_name);
+ EXCEPTION
+ WHEN feature_not_supported
+ THEN RAISE NOTICE 'cannot access temporary tables of other sessions';
+ END;
+
+ -- LOCK operation must fail due to 'cannot access temporary tables
+ -- of other sessions' error
+ BEGIN
+ EXECUTE format('BEGIN;
+ LOCK TABLE %I.test_tmp;
+ COMMIT;',
+ schema_name);
+ EXCEPTION
+ WHEN feature_not_supported
+ THEN RAISE NOTICE 'cannot access temporary tables of other sessions';
+ END;
+
+ -- DROP operation must fail due to 'cannot access temporary tables
+ -- of other sessions' error
+ BEGIN
+ EXECUTE format('DROP TABLE %I.test_tmp;', schema_name);
+ EXCEPTION
+ WHEN feature_not_supported
+ THEN RAISE NOTICE 'cannot access temporary tables of other sessions';
+ END;
+ END
+ $$;
+}
+
+permutation
+ s1_st1
+ s1_st2
+ s2_st1
\ No newline at end of file
--
2.43.0
