- Removed @unsupported

14 files changed, 166 insertions, 113 deletions

diff --git a/test/engine/execute.py b/test/engine/execute.py
index 5a42c2dd0..80f4e390c 100644
--- a/test/engine/execute.py
+++ b/test/engine/execute.py
@@ -49,7 +49,7 @@ class ExecuteTest(TestBase):
 
     # pyformat is supported for mysql, but skipping because a few driver
     # versions have a bug that bombs out on this test. (1.2.2b3, 1.2.2c1, 1.2.2)
-    @testing.unsupported('mysql', 'supported but not covered for MySQLdb')
+    @testing.skip_if(lambda: testing.against('mysql'), 'db-api flaky')
     @testing.fails_on_everything_except('postgres')
     def test_raw_python(self):
         for conn in (testing.db, testing.db.connect()):
diff --git a/test/engine/reflection.py b/test/engine/reflection.py
index ebb79154e..3995fdedc 100644
--- a/test/engine/reflection.py
+++ b/test/engine/reflection.py
@@ -418,7 +418,7 @@ class ReflectionTest(TestBase, ComparesTables):
             meta.drop_all()
 
 
-    @testing.unsupported('oracle', 'FIXME: unknown, confirm not fails_on')
+    @testing.crashes('oracle', 'FIXME: unknown, confirm not fails_on')
     def testreserved(self):
         # check a table that uses an SQL reserved name doesn't cause an error
         meta = MetaData(testing.db)
@@ -676,7 +676,7 @@ class SchemaTest(TestBase):
             assert buf.index("CREATE TABLE someschema.table1") > -1
             assert buf.index("CREATE TABLE someschema.table2") > -1
 
-    @testing.unsupported('firebird', 'FIXME: unknown- no schema support in db?')
+    @testing.crashes('firebird', 'FIXME: unknown- no schema support in db?')
     @testing.fails_on('sqlite')
     # fixme: revisit these below.
     @testing.fails_on('access', 'oracle', 'mssql', 'sybase')
diff --git a/test/engine/transaction.py b/test/engine/transaction.py
index 50d38d699..69d35748b 100644
--- a/test/engine/transaction.py
+++ b/test/engine/transaction.py
@@ -732,11 +732,11 @@ class ForUpdateTest(TestBase):
                 break
         con.close()
 
-    @testing.unsupported('sqlite', 'needs n threads -> 1 :memory: db')
-    @testing.unsupported('mssql', 'FIXME: unknown')
-    @testing.unsupported('firebird', 'FIXME: unknown')
-    @testing.unsupported('sybase', 'FIXME: unknown')
-    @testing.unsupported('access', 'FIXME: unknown')
+    @testing.crashes('mssql', 'FIXME: unknown')
+    @testing.crashes('firebird', 'FIXME: unknown')
+    @testing.crashes('sybase', 'FIXME: unknown')
+    @testing.crashes('access', 'FIXME: unknown')
+    @testing.requires.independent_connections
     def test_queued_update(self):
         """Test SELECT FOR UPDATE with concurrent modifications.
 
@@ -798,11 +798,11 @@ class ForUpdateTest(TestBase):
 
         return errors
 
-    @testing.unsupported('sqlite', 'needs n threads -> 1 memory db')
-    @testing.unsupported('mssql', 'FIXME: unknown')
-    @testing.unsupported('firebird', 'FIXME: unknown')
-    @testing.unsupported('sybase', 'FIXME: unknown')
-    @testing.unsupported('access', 'FIXME: unknown')
+    @testing.crashes('mssql', 'FIXME: unknown')
+    @testing.crashes('firebird', 'FIXME: unknown')
+    @testing.crashes('sybase', 'FIXME: unknown')
+    @testing.crashes('access', 'FIXME: unknown')
+    @testing.requires.independent_connections
     def test_queued_select(self):
         """Simple SELECT FOR UPDATE conflict test"""
 
@@ -811,12 +811,12 @@ class ForUpdateTest(TestBase):
             sys.stderr.write("Failure: %s\n" % e)
         self.assert_(len(errors) == 0)
 
-    @testing.unsupported('sqlite', 'needs n threads -> 1 memory db')
-    @testing.unsupported('mssql', 'FIXME: unknown')
-    @testing.unsupported('mysql', 'no support for NOWAIT')
-    @testing.unsupported('firebird', 'FIXME: unknown')
-    @testing.unsupported('sybase', 'FIXME: unknown')
-    @testing.unsupported('access', 'FIXME: unknown')
+    @testing.crashes('mssql', 'FIXME: unknown')
+    @testing.fails_on('mysql') # no support for NOWAIT
+    @testing.crashes('firebird', 'FIXME: unknown')
+    @testing.crashes('sybase', 'FIXME: unknown')
+    @testing.crashes('access', 'FIXME: unknown')
+    @testing.requires.independent_connections
     def test_nowait_select(self):
         """Simple SELECT FOR UPDATE NOWAIT conflict test"""
 
diff --git a/test/orm/assorted_eager.py b/test/orm/assorted_eager.py
index 76fcd869d..ab59d5a44 100644
--- a/test/orm/assorted_eager.py
+++ b/test/orm/assorted_eager.py
@@ -178,7 +178,7 @@ class EagerTest(_base.MappedTest):
         result = ["%d %s" % ( t.id,t.category.name ) for t in l]
         eq_(result, [u'1 Some Category', u'3 Some Category'])
 
-    @testing.unsupported('sybase', 'FIXME: unknown, verify not fails_on')
+    @testing.crashes('sybase', 'FIXME: unknown, verify not fails_on')
     @testing.resolve_artifact_names
     def test_without_outerjoin_literal(self):
         s = create_session()
diff --git a/test/orm/generative.py b/test/orm/generative.py
index 3fcbf2918..652823b28 100644
--- a/test/orm/generative.py
+++ b/test/orm/generative.py
@@ -35,7 +35,7 @@ class GenerativeQueryTest(_base.MappedTest):
         assert res.order_by([Foo.bar])[0].bar == 5
         assert res.order_by([sa.desc(Foo.bar)])[0].bar == 95
 
-    @testing.unsupported('mssql', 'FIXME: verify not fails_on()')
+    @testing.crashes('mssql', 'FIXME: verify not fails_on()')
     @testing.fails_on('maxdb')
     @testing.resolve_artifact_names
     def test_slice(self):
diff --git a/test/orm/query.py b/test/orm/query.py
index d2550427c..911155692 100644
--- a/test/orm/query.py
+++ b/test/orm/query.py
@@ -16,6 +16,7 @@ from orm import _fixtures
 
 from sqlalchemy.orm.util import join, outerjoin, with_parent
 
+
 class QueryTest(FixtureTest):
     keep_mappers = True
     keep_data = True
@@ -414,7 +415,7 @@ class FilterTest(QueryTest):
 
         assert [User(id=10)] == sess.query(User).outerjoin("addresses", aliased=True).filter(~User.addresses.any()).all()
         
-    @testing.unsupported('maxdb', 'can dump core')
+    @testing.crashes('maxdb', 'can dump core')
     def test_has(self):
         sess = create_session()
         assert [Address(id=5)] == sess.query(Address).filter(Address.user.has(name='fred')).all()
diff --git a/test/orm/session.py b/test/orm/session.py
index 3eaa2ec29..058548e2c 100644
--- a/test/orm/session.py
+++ b/test/orm/session.py
@@ -151,8 +151,8 @@ class SessionTest(_fixtures.FixtureTest):
         assert len(session.query(User).filter_by(name='Johnny').all()) == 0
         session.close()
 
-    @testing.unsupported('mssql', 'test causes mssql to hang')
-    @testing.unsupported('sqlite', 'needs true independent connections')
+    @testing.crashes('mssql', 'test causes mssql to hang')
+    @testing.requires.independent_connections
     @engines.close_open_connections
     @testing.resolve_artifact_names
     def test_transaction(self):
@@ -171,8 +171,8 @@ class SessionTest(_fixtures.FixtureTest):
         assert testing.db.connect().execute("select count(1) from users").scalar() == 1
         sess.close()
 
-    @testing.unsupported('mssql', 'test causes mssql to hang')
-    @testing.unsupported('sqlite', 'needs true independent connections')
+    @testing.crashes('mssql', 'test causes mssql to hang')
+    @testing.requires.independent_connections
     @engines.close_open_connections
     @testing.resolve_artifact_names
     def test_autoflush(self):
@@ -206,8 +206,8 @@ class SessionTest(_fixtures.FixtureTest):
         eq_(sess.query(Address).filter(Address.user==u).one(),
             Address(email_address='foo'))
 
-    @testing.unsupported('mssql', 'test causes mssql to hang')
-    @testing.unsupported('sqlite', 'needs true independent connections')
+    @testing.crashes('mssql', 'test causes mssql to hang')
+    @testing.requires.independent_connections
     @engines.close_open_connections
     @testing.resolve_artifact_names
     def test_autoflush_unbound(self):
diff --git a/test/orm/unitofwork.py b/test/orm/unitofwork.py
index a6ff5cc76..a05a7aa51 100644
--- a/test/orm/unitofwork.py
+++ b/test/orm/unitofwork.py
@@ -16,6 +16,7 @@ from orm import _base, _fixtures
 from engine import _base as engine_base
 import pickleable
 
+
 class UnitOfWorkTest(object):
     pass
 
@@ -658,7 +659,7 @@ class ClauseAttributesTest(_base.MappedTest):
         eq_(u.name, 'test2')
         eq_(u.counter,  2)
 
-    @testing.unsupported('mssql', 'FIXME: unknown, verify not fails_on()')
+    @testing.crashes('mssql', 'FIXME: unknown, verify not fails_on()')
     @testing.resolve_artifact_names
     def test_insert(self):
         u = User(name='test', counter=sa.select([5]))
diff --git a/test/sql/defaults.py b/test/sql/defaults.py
index dafab1fd0..8beb016ab 100644
--- a/test/sql/defaults.py
+++ b/test/sql/defaults.py
@@ -385,7 +385,7 @@ class PKDefaultTest(TestBase):
     def tearDownAll(self):
         metadata.drop_all()
 
-    @testing.unsupported('mssql', 'FIXME: unknown, verify not fails_on')
+    @testing.crashes('mssql', 'FIXME: unknown, verify not fails_on')
     def test_basic(self):
         t2.insert().execute(nextid=1)
         r = t1.insert().execute(data='hi')
diff --git a/test/sql/query.py b/test/sql/query.py
index 098e709b2..2dad9c695 100644
--- a/test/sql/query.py
+++ b/test/sql/query.py
@@ -296,7 +296,7 @@ class QueryTest(TestBase):
         r = users.select(limit=3, order_by=[users.c.user_id]).execute().fetchall()
         self.assert_(r == [(1, 'john'), (2, 'jack'), (3, 'ed')], repr(r))
 
-    @testing.unsupported('mssql', 'FIXME: guessing')
+    @testing.crashes('mssql', 'FIXME: guessing')
     @testing.fails_on('maxdb')
     def test_select_limit_offset(self):
         users.insert().execute(user_id=1, user_name='john')
@@ -492,9 +492,9 @@ class QueryTest(TestBase):
         self.assertEqual([x.lower() for x in r.keys()], ['user_name', 'user_id'])
         self.assertEqual(r.values(), ['foo', 1])
 
-    @testing.unsupported('oracle', 'FIXME: unknown, varify not fails_on()')
-    @testing.unsupported('firebird', 'FIXME: unknown, verify not fails_on()')
-    @testing.unsupported('maxdb', 'FIXME: unknown, verify not fails_on()')
+    @testing.crashes('oracle', 'FIXME: unknown, varify not fails_on()')
+    @testing.crashes('firebird', 'FIXME: unknown, verify not fails_on()')
+    @testing.crashes('maxdb', 'FIXME: unknown, verify not fails_on()')
     def test_column_accessor_shadow(self):
         meta = MetaData(testing.db)
         shadowed = Table('test_shadowed', meta,
@@ -668,7 +668,7 @@ class CompoundTest(TestBase):
                   ('ccc', 'aaa')]
         self.assertEquals(u.alias('bar').select().execute().fetchall(), wanted)
 
-    @testing.unsupported('oracle', 'FIXME: unknown, verify not fails_on')
+    @testing.crashes('oracle', 'FIXME: unknown, verify not fails_on')
     @testing.fails_on('mysql')
     @testing.fails_on('sqlite')
     def test_union_all(self):
@@ -687,8 +687,8 @@ class CompoundTest(TestBase):
         found2 = self._fetchall_sorted(e.alias('foo').select().execute())
         self.assertEquals(found2, wanted)
 
-    @testing.unsupported('firebird', 'FIXME: unknown, verify not fails_on')
-    @testing.unsupported('sybase', 'FIXME: unknown, verify not fails_on')
+    @testing.crashes('firebird', 'FIXME: unknown, verify not fails_on')
+    @testing.crashes('sybase', 'FIXME: unknown, verify not fails_on')
     @testing.fails_on('mysql')
     def test_intersect(self):
         i = intersect(
@@ -704,9 +704,9 @@ class CompoundTest(TestBase):
         found2 = self._fetchall_sorted(i.alias('bar').select().execute())
         self.assertEquals(found2, wanted)
 
-    @testing.unsupported('firebird', 'FIXME: unknown, verify not fails_on')
-    @testing.unsupported('oracle', 'FIXME: unknown, verify not fails_on')
-    @testing.unsupported('sybase', 'FIXME: unknown, verify not fails_on')
+    @testing.crashes('firebird', 'FIXME: unknown, verify not fails_on')
+    @testing.crashes('oracle', 'FIXME: unknown, verify not fails_on')
+    @testing.crashes('sybase', 'FIXME: unknown, verify not fails_on')
     @testing.fails_on('mysql')
     def test_except_style1(self):
         e = except_(union(
@@ -721,9 +721,9 @@ class CompoundTest(TestBase):
         found = self._fetchall_sorted(e.alias('bar').select().execute())
         self.assertEquals(found, wanted)
 
-    @testing.unsupported('firebird', 'FIXME: unknown, verify not fails_on')
-    @testing.unsupported('oracle', 'FIXME: unknown, verify not fails_on')
-    @testing.unsupported('sybase', 'FIXME: unknown, verify not fails_on')
+    @testing.crashes('firebird', 'FIXME: unknown, verify not fails_on')
+    @testing.crashes('oracle', 'FIXME: unknown, verify not fails_on')
+    @testing.crashes('sybase', 'FIXME: unknown, verify not fails_on')
     @testing.fails_on('mysql')
     def test_except_style2(self):
         e = except_(union(
@@ -741,9 +741,9 @@ class CompoundTest(TestBase):
         found2 = self._fetchall_sorted(e.alias('bar').select().execute())
         self.assertEquals(found2, wanted)
 
-    @testing.unsupported('firebird', 'FIXME: unknown, verify not fails_on')
-    @testing.unsupported('oracle', 'FIXME: unknown, verify not fails_on')
-    @testing.unsupported('sybase', 'FIXME: unknown, verify not fails_on')
+    @testing.crashes('firebird', 'FIXME: unknown, verify not fails_on')
+    @testing.crashes('oracle', 'FIXME: unknown, verify not fails_on')
+    @testing.crashes('sybase', 'FIXME: unknown, verify not fails_on')
     @testing.fails_on('mysql')
     @testing.fails_on('sqlite')
     def test_except_style3(self):
@@ -759,7 +759,7 @@ class CompoundTest(TestBase):
         self.assertEquals(e.alias('foo').select().execute().fetchall(),
                           [('ccc',)])
 
-    @testing.unsupported('firebird', 'FIXME: unknown, verify not fails_on')
+    @testing.crashes('firebird', 'FIXME: unknown, verify not fails_on')
     @testing.fails_on('mysql')
     def test_composite(self):
         u = intersect(
@@ -775,7 +775,7 @@ class CompoundTest(TestBase):
 
         self.assertEquals(found, wanted)
 
-    @testing.unsupported('firebird', 'FIXME: unknown, verify not fails_on')
+    @testing.crashes('firebird', 'FIXME: unknown, verify not fails_on')
     @testing.fails_on('mysql')
     def test_composite_alias(self):
         ua = intersect(
diff --git a/test/sql/quote.py b/test/sql/quote.py
index 2e5910c7b..7003ce834 100644
--- a/test/sql/quote.py
+++ b/test/sql/quote.py
@@ -4,11 +4,12 @@ from sqlalchemy import sql
 from sqlalchemy.sql import compiler
 from testlib import *
 
+
 class QuoteTest(TestBase, AssertsCompiledSQL):
     def setUpAll(self):
-        # TODO: figure out which databases/which identifiers allow special characters to be used,
-        # such as:  spaces, quote characters, punctuation characters, set up tests for those as
-        # well.
+        # TODO: figure out which databases/which identifiers allow special
+        # characters to be used, such as: spaces, quote characters,
+        # punctuation characters, set up tests for those as well.
         global table1, table2, table3
         metadata = MetaData(testing.db)
         table1 = Table('WorstCase1', metadata,
@@ -67,24 +68,24 @@ class QuoteTest(TestBase, AssertsCompiledSQL):
         res2 = select([table2.c.d123, table2.c.u123, table2.c.MixedCase], use_labels=True).execute().fetchall()
         print res2
         assert(res2==[(1,2,3),(2,2,3),(4,3,2)])
-    
+
     def test_quote_flag(self):
         metadata = MetaData()
-        t1 = Table('TableOne', metadata, 
+        t1 = Table('TableOne', metadata,
             Column('ColumnOne', Integer), schema="FooBar")
         self.assert_compile(t1.select(), '''SELECT "FooBar"."TableOne"."ColumnOne" FROM "FooBar"."TableOne"''')
 
         metadata = MetaData()
-        t1 = Table('t1', metadata, 
+        t1 = Table('t1', metadata,
             Column('col1', Integer, quote=True), quote=True, schema="foo", quote_schema=True)
         self.assert_compile(t1.select(), '''SELECT "foo"."t1"."col1" FROM "foo"."t1"''')
 
         metadata = MetaData()
-        t1 = Table('TableOne', metadata, 
+        t1 = Table('TableOne', metadata,
             Column('ColumnOne', Integer, quote=False), quote=False, schema="FooBar", quote_schema=False)
         self.assert_compile(t1.select(), '''SELECT FooBar.TableOne.ColumnOne FROM FooBar.TableOne''')
-        
-    @testing.unsupported('oracle', 'FIXME: unknown, verify not fails_on')
+
+    @testing.crashes('oracle', 'FIXME: unknown, verify not fails_on')
     @testing.requires.subqueries
     def testlabels(self):
         """test the quoting of labels.
@@ -109,12 +110,12 @@ class QuoteTest(TestBase, AssertsCompiledSQL):
         # note that 'foo' and 'FooCol' are literals already quoted
         x = select([sql.literal_column("'foo'").label("somelabel")], from_obj=[table]).alias("AnAlias")
         x = x.select()
-        self.assert_compile(x, 
+        self.assert_compile(x,
             '''SELECT "AnAlias".somelabel FROM (SELECT 'foo' AS somelabel FROM "ImATable") AS "AnAlias"''')
 
         x = select([sql.literal_column("'FooCol'").label("SomeLabel")], from_obj=[table])
         x = x.select()
-        self.assert_compile(x, 
+        self.assert_compile(x,
             '''SELECT "SomeLabel" FROM (SELECT 'FooCol' AS "SomeLabel" FROM "ImATable")''')
 
 
diff --git a/test/sql/testtypes.py b/test/sql/testtypes.py
index 3e9f1d631..56bd61499 100644
--- a/test/sql/testtypes.py
+++ b/test/sql/testtypes.py
@@ -8,7 +8,6 @@ from sqlalchemy.databases import mssql, oracle, mysql, postgres, firebird
 from testlib import *
 
 
-
 class AdaptTest(TestBase):
     def testadapt(self):
         e1 = url.URL('postgres').get_dialect()()
@@ -381,7 +380,7 @@ class UnicodeTest(TestBase, AssertsExecutionResults):
             testing.db.engine.dialect.convert_unicode = prev_unicode
             testing.db.engine.dialect.convert_unicode = prev_assert
 
-    @testing.unsupported('oracle', 'FIXME: unknown, verify not fails_on')
+    @testing.crashes('oracle', 'FIXME: unknown, verify not fails_on')
     @testing.fails_on('firebird') # "Data type unknown" on the parameter
     def testlength(self):
         """checks the database correctly understands the length of a unicode string"""
diff --git a/test/testlib/requires.py b/test/testlib/requires.py
index 7c345ee6e..a382f42bc 100644
--- a/test/testlib/requires.py
+++ b/test/testlib/requires.py
@@ -6,64 +6,65 @@ target database.
 """
 
 from testlib.testing import \
+     _block_unconditionally as no_support, \
      _chain_decorators_on, \
-     exclude, \
-     unsupported
+     exclude
 
 
-def sequences(fn):
-    """Target database must support SEQUENCEs."""
+def deferrable_constraints(fn):
+    """Target database must support derferable constraints."""
     return _chain_decorators_on(
         fn,
-        unsupported('access', 'no SEQUENCE support'),
-        unsupported('mssql', 'no SEQUENCE support'),
-        unsupported('mysql', 'no SEQUENCE support'),
-        unsupported('sqlite', 'no SEQUENCE support'),
-        unsupported('sybase', 'no SEQUENCE support'),
+        no_support('mysql', 'not supported by database'),
+        no_support('mssql', 'not supported by database'),
         )
 
-def savepoints(fn):
-    """Target database must support savepoints."""
+def foreign_keys(fn):
+    """Target database must support foreign keys."""
     return _chain_decorators_on(
         fn,
-        unsupported('access', 'FIXME: guessing, needs confirmation'),
-        unsupported('mssql', 'FIXME: guessing, needs confirmation'),
-        unsupported('sqlite', 'not supported by database'),
-        unsupported('sybase', 'FIXME: guessing, needs confirmation'),
-        exclude('mysql', '<', (5, 0, 3), 'not supported by database'),
+        no_support('sqlite', 'not supported by database'),
         )
 
-def two_phase_transactions(fn):
-    """Target database must support two-phase transactions."""
+def independent_connections(fn):
+    """Target must support simultaneous, independent database connections."""
+
+    # This is also true of some configurations of UnixODBC and probably win32
+    # ODBC as well.
     return _chain_decorators_on(
         fn,
-        unsupported('access', 'FIXME: guessing, needs confirmation'),
-        unsupported('firebird', 'no SA implementation'),
-        unsupported('maxdb', 'not supported by database'),
-        unsupported('mssql', 'FIXME: guessing, needs confirmation'),
-        unsupported('oracle', 'no SA implementation'),
-        unsupported('sqlite', 'not supported by database'),
-        unsupported('sybase', 'FIXME: guessing, needs confirmation'),
-        exclude('mysql', '<', (5, 0, 3), 'not supported by database'),
+        no_support('sqlite', 'no driver support')
         )
 
-def unicode_connections(fn):
-    """Target driver must support some encoding of Unicode across the wire."""
-    # TODO: expand to exclude MySQLdb versions w/ broken unicode
+def row_triggers(fn):
+    """Target must support standard statement-running EACH ROW triggers."""
     return _chain_decorators_on(
         fn,
-        exclude('mysql', '<', (4, 1, 1), 'no unicode connection support'),
+        # no access to same table
+        exclude('mysql', '<', (5, 0, 10), 'not supported by database'),
+        no_support('postgres', 'not supported by database: no statements'),
         )
 
-def unicode_ddl(fn):
-    """Target driver must support some encoding of Unicode across the wire."""
-    # TODO: expand to exclude MySQLdb versions w/ broken unicode
+def savepoints(fn):
+    """Target database must support savepoints."""
     return _chain_decorators_on(
         fn,
-        unsupported('maxdb', 'database support flakey'),
-        unsupported('oracle', 'FIXME: no support in database?'),
-        unsupported('sybase', 'FIXME: guessing, needs confirmation'),
-        exclude('mysql', '<', (4, 1, 1), 'no unicode connection support'),
+        no_support('access', 'FIXME: guessing, needs confirmation'),
+        no_support('mssql', 'FIXME: guessing, needs confirmation'),
+        no_support('sqlite', 'not supported by database'),
+        no_support('sybase', 'FIXME: guessing, needs confirmation'),
+        exclude('mysql', '<', (5, 0, 3), 'not supported by database'),
+        )
+
+def sequences(fn):
+    """Target database must support SEQUENCEs."""
+    return _chain_decorators_on(
+        fn,
+        no_support('access', 'no SEQUENCE support'),
+        no_support('mssql', 'no SEQUENCE support'),
+        no_support('mysql', 'no SEQUENCE support'),
+        no_support('sqlite', 'no SEQUENCE support'),
+        no_support('sybase', 'no SEQUENCE support'),
         )
 
 def subqueries(fn):
@@ -73,26 +74,35 @@ def subqueries(fn):
         exclude('mysql', '<', (4, 1, 1), 'no subquery support'),
         )
 
-def foreign_keys(fn):
-    """Target database must support foreign keys."""
+def two_phase_transactions(fn):
+    """Target database must support two-phase transactions."""
     return _chain_decorators_on(
         fn,
-        unsupported('sqlite', 'not supported by database'),
+        no_support('access', 'FIXME: guessing, needs confirmation'),
+        no_support('firebird', 'no SA implementation'),
+        no_support('maxdb', 'not supported by database'),
+        no_support('mssql', 'FIXME: guessing, needs confirmation'),
+        no_support('oracle', 'no SA implementation'),
+        no_support('sqlite', 'not supported by database'),
+        no_support('sybase', 'FIXME: guessing, needs confirmation'),
+        exclude('mysql', '<', (5, 0, 3), 'not supported by database'),
         )
 
-def deferrable_constraints(fn):
-    """Target database must support derferable constraints."""
+def unicode_connections(fn):
+    """Target driver must support some encoding of Unicode across the wire."""
+    # TODO: expand to exclude MySQLdb versions w/ broken unicode
     return _chain_decorators_on(
         fn,
-        unsupported('mysql', 'not supported by database'),
-        unsupported('mssql', 'not supported by database'),
+        exclude('mysql', '<', (4, 1, 1), 'no unicode connection support'),
         )
 
-def row_triggers(fn):
-    """Target must support standard statement-running EACH ROW triggers."""
+def unicode_ddl(fn):
+    """Target driver must support some encoding of Unicode across the wire."""
+    # TODO: expand to exclude MySQLdb versions w/ broken unicode
     return _chain_decorators_on(
         fn,
-        # no access to same table
-        exclude('mysql', '<', (5, 0, 10), 'not supported by database'),
-        unsupported('postgres', 'not supported by database: no statements'),
+        no_support('maxdb', 'database support flakey'),
+        no_support('oracle', 'FIXME: no support in database?'),
+        no_support('sybase', 'FIXME: guessing, needs confirmation'),
+        exclude('mysql', '<', (4, 1, 1), 'no unicode connection support'),
         )
diff --git a/test/testlib/testing.py b/test/testlib/testing.py
index c31e59156..c816963e4 100644
--- a/test/testlib/testing.py
+++ b/test/testlib/testing.py
@@ -147,13 +147,37 @@ def fails_on_everything_except(*dbs):
         return _function_named(maybe, fn_name)
     return decorate
 
-def unsupported(db, reason):
+def crashes(db, reason):
     """Mark a test as unsupported by a database implementation.
 
-    'unsupported' tests will be skipped unconditionally.  Useful for feature
-    tests that cause deadlocks or other fatal problems.
+    'crashes' tests will be skipped unconditionally.  Use for feature tests
+    that cause deadlocks or other fatal problems.
+
     """
+    carp = _should_carp_about_exclusion(reason)
+    def decorate(fn):
+        fn_name = fn.__name__
+        def maybe(*args, **kw):
+            if config.db.name == db:
+                msg = "'%s' unsupported on DB implementation '%s': %s" % (
+                    fn_name, config.db.name, reason)
+                print msg
+                if carp:
+                    print >> sys.stderr, msg
+                return True
+            else:
+                return fn(*args, **kw)
+        return _function_named(maybe, fn_name)
+    return decorate
 
+def _block_unconditionally(db, reason):
+    """Mark a test as unsupported by a database implementation.
+
+    Will never run the test against any version of the given database, ever,
+    no matter what.  Use when your assumptions are infallible; past, present
+    and future.
+
+    """
     carp = _should_carp_about_exclusion(reason)
     def decorate(fn):
         fn_name = fn.__name__
@@ -170,6 +194,7 @@ def unsupported(db, reason):
         return _function_named(maybe, fn_name)
     return decorate
 
+
 def exclude(db, op, spec, reason):
     """Mark a test as unsupported by specific database server versions.
 
@@ -242,6 +267,22 @@ def _server_version(bind=None):
         bind = config.db
     return bind.dialect.server_version_info(bind.contextual_connect())
 
+def skip_if(predicate, reason=None):
+    """Skip a test if predicate is true."""
+    reason = reason or predicate.__name__
+    def decorate(fn):
+        fn_name = fn.__name__
+        def maybe(*args, **kw):
+            if predicate():
+                msg = "'%s' skipped on DB %s version '%s': %s" % (
+                    fn_name, config.db.name, _server_version(), reason)
+                print msg
+                return True
+            else:
+                return fn(*args, **kw)
+        return _function_named(maybe, fn_name)
+    return decorate
+
 def emits_warning(*messages):
     """Mark a test as emitting a warning.