Allow test tables to use a specific gitlab schema

Update GitlabSchema to allow tables prefixed with _test_ to also specify
a schema they should use, rather than making them all :gitlab_shared.

lib/gitlab/database/gitlab_schema.rb

@@ -78,7 +78,11 @@ module Gitlab
         # All tables from `information_schema.` are `:gitlab_shared`
         return :gitlab_shared if schema_name == 'information_schema'
 
-        # All tables that start with `_test_` are shared and ignored
+        return :gitlab_main if table_name.start_with?('_test_gitlab_main_')
+
+        return :gitlab_ci if table_name.start_with?('_test_gitlab_ci_')
+
+        # All tables that start with `_test_` without a following schema are shared and ignored
         return :gitlab_shared if table_name.start_with?('_test_')
 
         # All `pg_` tables are marked as `shared`

spec/lib/gitlab/database/gitlab_schema_spec.rb

@@ -44,6 +44,8 @@ RSpec.describe Gitlab::Database::GitlabSchema do
       'my_schema.ci_builds'             | :gitlab_ci
       'information_schema.columns'      | :gitlab_shared
       'audit_events_part_5fc467ac26'    | :gitlab_main
+      '_test_gitlab_main_table'         | :gitlab_main
+      '_test_gitlab_ci_table'           | :gitlab_ci
       '_test_my_table'                  | :gitlab_shared
       'pg_attribute'                    | :gitlab_shared
       'my_other_table'                  | :undefined_my_other_table

spec/models/concerns/after_commit_queue_spec.rb

@@ -75,7 +75,7 @@ RSpec.describe AfterCommitQueue do
         skip_if_multiple_databases_not_setup
 
         table_sql = <<~SQL
-          CREATE TABLE _test_ci_after_commit_queue (
+          CREATE TABLE _test_gitlab_ci_after_commit_queue (
             id serial NOT NULL PRIMARY KEY);
         SQL
 
@@ -84,7 +84,7 @@ RSpec.describe AfterCommitQueue do
 
       let(:ci_klass) do
         Class.new(Ci::ApplicationRecord) do
-          self.table_name = '_test_ci_after_commit_queue'
+          self.table_name = '_test_gitlab_ci_after_commit_queue'
 
           include AfterCommitQueue