diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 5348bfb..61fb21f 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -74,3 +74,15 @@ jobs:
         run: curl -sL https://git.io/cpm | sudo perl - install -g --with-recommends --with-test --with-configure --show-build-log-on-failure --feature=test_postgresql --feature=test_fork
       - name: Run tests
         run: DOD_TEST_DRIVER=PostgreSQL prove -lr -j4 t
+
+  xt-tests:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v1
+      - name: perl -V
+        run: perl -V
+      - name: Install dependencies
+        run: curl -sL https://git.io/cpm | sudo perl - install -g --with-recommends --with-test --with-configure --show-build-log-on-failure
+      - name: Run tests
+        run: prove -lr xt
diff --git a/META.json b/META.json
index e3f3ac6..52a798a 100644
--- a/META.json
+++ b/META.json
@@ -120,11 +120,12 @@
             "Class::Trigger" : "0",
             "DBI" : "0",
             "List::Util" : "0",
-            "perl" : "5.006001"
+            "perl" : "5.008001"
          }
       },
       "test" : {
          "requires" : {
+            "Digest::SHA" : "0",
             "Tie::IxHash" : "0",
             "version" : "0"
          }
diff --git a/cpanfile b/cpanfile
index 3ea7334..d8c9b94 100644
--- a/cpanfile
+++ b/cpanfile
@@ -3,7 +3,7 @@ requires 'Class::Data::Inheritable';
 requires 'Class::Trigger';
 requires 'DBI';
 requires 'List::Util';
-requires 'perl', '5.006001';
+requires 'perl', '5.008001';
 recommends 'Text::SimpleTable';
 
 on configure => sub {
diff --git a/lib/Data/ObjectDriver/SQL.pm b/lib/Data/ObjectDriver/SQL.pm
index d5d8622..db1e1f9 100644
--- a/lib/Data/ObjectDriver/SQL.pm
+++ b/lib/Data/ObjectDriver/SQL.pm
@@ -707,6 +707,10 @@ The list of name of indexes which to use.
 
 Returns the SQL fully representing the SQL statement C<$sql>.
 
+=head2 C<$sql-E<gt>as_subquery($alias)>
+
+Returns a string representation of C<$sql> as a subquery. C<$alias> is optional.
+
 =head2 C<$sql-E<gt>as_sql_having()>
 
 Returns the SQL representing the C<HAVING> portion of C<$sql>'s C<GROUP ...
@@ -725,6 +729,10 @@ Returns the SQL for the C<LIMIT ... OFFSET> clause of the statement.
 Returns the SQL representing the aggregation clause of type C<$set> for the SQL
 statement C<$sql>. Reasonable values of C<$set> are C<ORDER> and C<GROUP>.
 
+=head2 C<$sql-E<gt>as_escape()>
+
+Returns a string representing the C<ESCAPE> clause for C<LIKE> predicates.
+
 =head1 DIAGNOSTICS
 
 =over 4