Stabilize regression tests

During the AUTOVACUUM regression tests, unintended AUTOVACUUM runs
occasionally occurred on unrelated catalogs, notably in pg_collation,
causing test failures. Given that the information from theses tables
was not crucial for the tests, the check targets are limited to the
public schema.

(fix #138)

test/expected/function-logger.out

@@ -68,11 +68,10 @@ DELETE 4001
 (1 row)
 
 /**--- Collect the AUTOVACUUM information ---**/
- instid | database  |   schema   |   table   | start | index_scans | page_removed | page_remain | tup_removed | tup_remain | tup_dead | page_hit | page_miss | page_dirty | read_rate | write_rate | duration 
---------+-----------+------------+-----------+-------+-------------+--------------+-------------+-------------+------------+----------+----------+-----------+------------+-----------+------------+----------
-      1 | postgres  | public     | tbl01     | xxx   | xxx         | xxx          | xxx         | xxx         | xxx        | xxx      | xxx      | xxx       | xxx        | xxx       | xxx        | xxx
-      1 | template1 | pg_catalog | pg_depend | xxx   | xxx         | xxx          | xxx         | xxx         | xxx        | xxx      | xxx      | xxx       | xxx        | xxx       | xxx        | xxx
-(2 rows)
+ instid | database | schema | table | start | index_scans | page_removed | page_remain | tup_removed | tup_remain | tup_dead | page_hit | page_miss | page_dirty | read_rate | write_rate | duration 
+--------+----------+--------+-------+-------+-------------+--------------+-------------+-------------+------------+----------+----------+-----------+------------+-----------+------------+----------
+      1 | postgres | public | tbl01 | xxx   | xxx         | xxx          | xxx         | xxx         | xxx        | xxx      | xxx      | xxx       | xxx        | xxx       | xxx        | xxx
+(1 row)
 
 /**--- Collect the cancelled AUTOVACUUM information ---**/
 server signaled

test/script/function-logger.sh

@@ -243,6 +243,8 @@ SELECT
 	CASE WHEN duration IS NOT NULL THEN 'xxx' END AS duration
 FROM
 	statsrepo.autovacuum
+WHERE
+	schema = 'public'
 ORDER BY
 	database, schema, "table";
 EOF