fix: 1261 pg custom query without creating view

third_party/ibis/ibis_postgres/client.py

@@ -72,22 +72,23 @@ def connect(dbapi_connection, connection_record):
 
 
 def _metadata(self, query: str) -> sch.Schema:
-    raw_name = util.guid()
-    name = self._quote(raw_name)
-    type_info_sql = """\
-    SELECT
-    attname,
-    format_type(atttypid, atttypmod) AS type
-    FROM pg_attribute
-    WHERE attrelid = CAST(:raw_name AS regclass)
-    AND attnum > 0
-    AND NOT attisdropped
-    ORDER BY attnum"""
     with self.begin() as con:
-        con.exec_driver_sql(f"CREATE TEMPORARY VIEW {name} AS {query}")
-        type_info = con.execute(sa.text(type_info_sql).bindparams(raw_name=raw_name))
-        yield from ((col, _get_type(typestr)) for col, typestr in type_info)
-        con.exec_driver_sql(f"DROP VIEW IF EXISTS {name}")
+        cur = con.exec_driver_sql(f"select * from ({query}) t0 limit 0")
+        qry_cols = [
+            f"('{column.name}'::text, {column.type_code},"
+            + f"{column.table_oid if column.table_oid else 'NULL'}::int,"
+            + f"{column.table_column if column.table_column else 'NULL'}::int, {idx})"
+            for idx, column in enumerate(cur.cursor.description)
+        ]
+        type_info = con.exec_driver_sql(
+            f"""select name, CASE WHEN t0.attrelid is NULL
+                                THEN format_type(t0.type_code, NULL)
+                                ELSE format_type(t1.atttypid, t1.atttypmod) END as type
+                    from unnest(array[{','.join(qry_cols)}])
+                    as t0(name text, type_code int, attrelid int, attnum int, col_ord int)
+                    left join pg_attribute t1 using (attrelid, attnum) order by col_ord"""
+        )
+    yield from ((col, _get_type(typestr)) for col, typestr in type_info)
 
 
 def _get_type(typestr: str) -> dt.DataType: