- The :meth:`.PGDialect.has_table` method will now query against

``pg_catalog.pg_table_is_visible(c.oid)``, rather than testing
for an exact schema match, when the schema name is None; this
so that the method will also illustrate that temporary tables
are present.  Note that this is a behavioral change, as Postgresql
allows a non-temporary table to silently overwrite an existing
temporary table of the same name, so this changes the behavior
of ``checkfirst`` in that unusual scenario.
fixes #3264

1 files changed, 2 insertions, 1 deletions

diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py
index baa640eaa..034ee9076 100644
--- a/lib/sqlalchemy/dialects/postgresql/base.py
+++ b/lib/sqlalchemy/dialects/postgresql/base.py
@@ -1942,7 +1942,8 @@ class PGDialect(default.DefaultDialect):
             cursor = connection.execute(
                 sql.text(
                     "select relname from pg_class c join pg_namespace n on "
-                    "n.oid=c.relnamespace where n.nspname=current_schema() "
+                    "n.oid=c.relnamespace where "
+                    "pg_catalog.pg_table_is_visible(c.oid) "
                     "and relname=:name",
                     bindparams=[
                         sql.bindparam('name', util.text_type(table_name),