diff --git a/.travis.yml b/.travis.yml
index 70e8be4a5..25b1b1b91 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -67,7 +67,7 @@ before_script:
 # Install composer dependencies
   - composer validate
   - mkdir ./public
-  - if [[ $DB == PGSQL ]]; then composer require silverstripe/postgresql:2.0.x-dev --no-update; fi
+  - if [[ $DB == PGSQL ]]; then composer require silverstripe/postgresql:2.1.x-dev --no-update; fi
   - if [[ $DB == SQLITE ]]; then composer require silverstripe/sqlite3:2.0.x-dev --no-update; fi
   - composer require silverstripe/recipe-testing:^1 silverstripe/recipe-core:4.2.x-dev silverstripe/admin:1.2.x-dev silverstripe/versioned:1.2.x-dev --no-update
   - if [[ $PHPUNIT_TEST == cms ]]; then composer require silverstripe/recipe-cms:4.2.x-dev --no-update; fi
diff --git a/src/Dev/SapphireTest.php b/src/Dev/SapphireTest.php
index c4c39ddd4..988f7f087 100644
--- a/src/Dev/SapphireTest.php
+++ b/src/Dev/SapphireTest.php
@@ -78,6 +78,14 @@ class SapphireTest extends PHPUnit_Framework_TestCase implements TestOnly
      */
     protected $usesDatabase = null;
 
+    /**
+     * This test will cleanup its state via transactions.
+     * If set to false a full schema is forced between tests, but at a performance cost.
+     *
+     * @var bool
+     */
+    protected $usesTransactions = true;
+
     /**
      * @var bool
      */
@@ -228,6 +236,14 @@ class SapphireTest extends PHPUnit_Framework_TestCase implements TestOnly
         return $this->usesDatabase;
     }
 
+    /**
+     * @return bool
+     */
+    public function getUsesTransactions()
+    {
+        return $this->usesTransactions;
+    }
+
     /**
      * @return array
      */
@@ -1188,7 +1204,7 @@ class SapphireTest extends PHPUnit_Framework_TestCase implements TestOnly
         if (strpos($fixtureFilePath, ':') !== false) {
             return ModuleResourceLoader::singleton()->resolvePath($fixtureFilePath);
         }
-        
+
         // Support fixture paths relative to the test class, rather than relative to webroot
         // String checking is faster than file_exists() calls.
         $resolvedPath = realpath($this->getCurrentAbsolutePath() . '/' . $fixtureFilePath);
diff --git a/src/Dev/State/FixtureTestState.php b/src/Dev/State/FixtureTestState.php
index ccbe67f1a..80ac22e4f 100644
--- a/src/Dev/State/FixtureTestState.php
+++ b/src/Dev/State/FixtureTestState.php
@@ -19,6 +19,13 @@ class FixtureTestState implements TestState
      */
     private $fixtureFactories = [];
 
+    /**
+     * Set if fixtures have been loaded
+     *
+     * @var bool
+     */
+    protected $loaded = [];
+
     /**
      * Called on setup
      *
@@ -26,25 +33,41 @@ class FixtureTestState implements TestState
      */
     public function setUp(SapphireTest $test)
     {
-        if ($this->testNeedsDB($test)) {
-            $tmpDB = $test::tempDB();
-            if (!$tmpDB->isUsed()) {
-                $tmpDB->build();
-            }
-            DataObject::singleton()->flushCache();
+        if (!$this->testNeedsDB($test)) {
+            return;
+        }
 
-            if (!$tmpDB->hasStarted()) {
-                foreach ($test->getRequireDefaultRecordsFrom() as $className) {
-                    $instance = singleton($className);
-                    if (method_exists($instance, 'requireDefaultRecords')) {
-                        $instance->requireDefaultRecords();
-                    }
-                    if (method_exists($instance, 'augmentDefaultRecords')) {
-                        $instance->augmentDefaultRecords();
-                    }
-                }
-                $this->loadFixtures($test);
+        // Ensure DB is built
+        $tmpDB = $test::tempDB();
+        if (!$tmpDB->isUsed()) {
+            // Build base db
+            $tmpDB->build();
+
+            // Reset schema
+            $extraObjects = $test->getExtraDataObjects();
+            if ($extraObjects) {
+                $tmpDB->resetDBSchema($extraObjects);
             }
+        }
+
+        DataObject::singleton()->flushCache();
+
+        // Ensure DB is built and populated
+        if (!$this->getIsLoaded(get_class($test))) {
+            foreach ($test->getRequireDefaultRecordsFrom() as $className) {
+                $instance = singleton($className);
+                if (method_exists($instance, 'requireDefaultRecords')) {
+                    $instance->requireDefaultRecords();
+                }
+                if (method_exists($instance, 'augmentDefaultRecords')) {
+                    $instance->augmentDefaultRecords();
+                }
+            }
+            $this->loadFixtures($test);
+        }
+
+        // Begin transactions if enabled
+        if ($test->getUsesTransactions()) {
             $tmpDB->startTransaction();
         }
     }
@@ -56,9 +79,21 @@ class FixtureTestState implements TestState
      */
     public function tearDown(SapphireTest $test)
     {
-        if ($this->testNeedsDB($test)) {
-            $test::tempDB()->rollbackTransaction();
+        if (!$this->testNeedsDB($test)) {
+            return;
         }
+
+        // For transactional states, rollback if possible
+        if ($test->getUsesTransactions()) {
+            $success = $test::tempDB()->rollbackTransaction();
+            if ($success) {
+                return;
+            }
+        }
+
+        // Force reset if transaction failed, or disabled
+        $test::tempDB()->kill();
+        $this->resetFixtureFactory(get_class($test));
     }
 
     /**
@@ -68,7 +103,7 @@ class FixtureTestState implements TestState
      */
     public function setUpOnce($class)
     {
-        $this->fixtureFactories[strtolower($class)] = Injector::inst()->create(FixtureFactory::class);
+        $this->resetFixtureFactory($class);
     }
 
     /**
@@ -130,6 +165,8 @@ class FixtureTestState implements TestState
         foreach ($paths as $fixtureFile) {
             $this->loadFixture($fixtureFile, $test);
         }
+        // Flag as loaded
+        $this->loaded[strtolower(get_class($test))] = true;
     }
 
     /**
@@ -220,4 +257,27 @@ class FixtureTestState implements TestState
 
         return false;
     }
+
+    /**
+     * Bootstrap a clean fixture factory for the given class
+     *
+     * @param string $class
+     */
+    protected function resetFixtureFactory($class)
+    {
+        $class = strtolower($class);
+        $this->fixtureFactories[$class] = Injector::inst()->create(FixtureFactory::class);
+        $this->loaded[$class] = false;
+    }
+
+    /**
+     * Check if fixtures need to be loaded for this class
+     *
+     * @param string $class Name of test to check
+     * @return bool
+     */
+    protected function getIsLoaded($class)
+    {
+        return !empty($this->loaded[strtolower($class)]);
+    }
 }
diff --git a/src/ORM/Connect/Database.php b/src/ORM/Connect/Database.php
index 3e2910522..4c60ed085 100644
--- a/src/ORM/Connect/Database.php
+++ b/src/ORM/Connect/Database.php
@@ -654,22 +654,40 @@ abstract class Database
      *
      * @param string|boolean $savepoint Name of savepoint, or leave empty to rollback
      * to last savepoint
+     * @return bool|null Boolean is returned if success state is known, or null if
+     * unknown. Note: For error checking purposes null should not be treated as error.
      */
     abstract public function transactionRollback($savepoint = false);
 
     /**
      * Commit everything inside this transaction so far
      *
-     * @param boolean $chain
+     * @param bool $chain
+     * @return bool|null Boolean is returned if success state is known, or null if
+     * unknown. Note: For error checking purposes null should not be treated as error.
      */
     abstract public function transactionEnd($chain = false);
 
+    /**
+     * Return depth of current transaction
+     *
+     * @return int Nesting level, or 0 if not in a transaction
+     */
+    public function transactionDepth()
+    {
+        // Placeholder error for transactional DBs that don't expose depth
+        if ($this->supportsTransactions()) {
+            user_error(get_class($this) . " does not support transactionDepth", E_USER_WARNING);
+        }
+        return 0;
+    }
+
     /**
      * Determines if the used database supports application-level locks,
      * which is different from table- or row-level locking.
      * See {@link getLock()} for details.
      *
-     * @return boolean Flag indicating that locking is available
+     * @return bool Flag indicating that locking is available
      */
     public function supportsLocks()
     {
@@ -681,7 +699,7 @@ abstract class Database
      * See {@link supportsLocks()} to check if locking is generally supported.
      *
      * @param string $name Name of the lock
-     * @return boolean
+     * @return bool
      */
     public function canLock($name)
     {
@@ -703,7 +721,7 @@ abstract class Database
      *
      * @param string $name Name of lock
      * @param integer $timeout Timeout in seconds
-     * @return boolean
+     * @return bool
      */
     public function getLock($name, $timeout = 5)
     {
@@ -715,7 +733,7 @@ abstract class Database
      * (if the execution aborts (e.g. due to an error) all locks are automatically released).
      *
      * @param string $name Name of the lock
-     * @return boolean Flag indicating whether the lock was successfully released
+     * @return bool Flag indicating whether the lock was successfully released
      */
     public function releaseLock($name)
     {
@@ -756,7 +774,7 @@ abstract class Database
      * Determine if the database with the specified name exists
      *
      * @param string $name Name of the database to check for
-     * @return boolean Flag indicating whether this database exists
+     * @return bool Flag indicating whether this database exists
      */
     public function databaseExists($name)
     {
@@ -778,12 +796,12 @@ abstract class Database
      * database if it doesn't exist in the current schema.
      *
      * @param string $name Name of the database
-     * @param boolean $create Flag indicating whether the database should be created
+     * @param bool $create Flag indicating whether the database should be created
      * if it doesn't exist. If $create is false and the database doesn't exist
      * then an error will be raised
-     * @param int|boolean $errorLevel The level of error reporting to enable for the query, or false if no error
+     * @param int|bool $errorLevel The level of error reporting to enable for the query, or false if no error
      * should be raised
-     * @return boolean Flag indicating success
+     * @return bool Flag indicating success
      */
     public function selectDatabase($name, $create = false, $errorLevel = E_USER_ERROR)
     {
diff --git a/src/ORM/Connect/MySQLDatabase.php b/src/ORM/Connect/MySQLDatabase.php
index fa3672db5..49f6dd62d 100644
--- a/src/ORM/Connect/MySQLDatabase.php
+++ b/src/ORM/Connect/MySQLDatabase.php
@@ -329,25 +329,78 @@ class MySQLDatabase extends Database
 
     public function transactionRollback($savepoint = false)
     {
+        // Named transaction
         if ($savepoint) {
             $this->query('ROLLBACK TO ' . $savepoint);
-        } else {
-            --$this->transactionNesting;
-            if ($this->transactionNesting > 0) {
-                $this->transactionRollback('NESTEDTRANSACTION' . $this->transactionNesting);
-            } else {
-                $this->query('ROLLBACK');
-            }
+            return true;
         }
+
+        // Fail if transaction isn't available
+        if (!$this->transactionNesting) {
+            return false;
+        }
+        --$this->transactionNesting;
+        if ($this->transactionNesting > 0) {
+            $this->transactionRollback('NESTEDTRANSACTION' . $this->transactionNesting);
+        } else {
+            $this->query('ROLLBACK');
+        }
+        return true;
+    }
+
+    public function transactionDepth()
+    {
+        return $this->transactionNesting;
     }
 
     public function transactionEnd($chain = false)
     {
+        // Fail if transaction isn't available
+        if (!$this->transactionNesting) {
+            return false;
+        }
         --$this->transactionNesting;
         if ($this->transactionNesting <= 0) {
             $this->transactionNesting = 0;
             $this->query('COMMIT AND ' . ($chain ? '' : 'NO ') . 'CHAIN');
         }
+        return true;
+    }
+
+    /**
+     * In error condition, set transactionNesting to zero
+     */
+    protected function resetTransactionNesting()
+    {
+        $this->transactionNesting = 0;
+    }
+
+    public function query($sql, $errorLevel = E_USER_ERROR)
+    {
+        $this->inspectQuery($sql);
+        return parent::query($sql, $errorLevel);
+    }
+
+    public function preparedQuery($sql, $parameters, $errorLevel = E_USER_ERROR)
+    {
+        $this->inspectQuery($sql);
+        return parent::preparedQuery($sql, $parameters, $errorLevel);
+    }
+
+    /**
+     * Inspect a SQL query prior to execution
+     *
+     * @param string $sql
+     */
+    protected function inspectQuery($sql)
+    {
+        // Any DDL discards transactions.
+        // See https://dev.mysql.com/doc/internals/en/transactions-notes-on-ddl-and-normal-transaction.html
+        // on why we need to be over-eager
+        $isDDL = $this->getConnector()->isQueryDDL($sql);
+        if ($isDDL) {
+            $this->resetTransactionNesting();
+        }
     }
 
     public function comparisonClause(
diff --git a/src/ORM/Connect/TempDatabase.php b/src/ORM/Connect/TempDatabase.php
index 832acd606..dce37959f 100644
--- a/src/ORM/Connect/TempDatabase.php
+++ b/src/ORM/Connect/TempDatabase.php
@@ -23,11 +23,6 @@ class TempDatabase
      */
     protected $name = null;
 
-    /**
-     * @var bool If a transaction has been started
-     */
-    protected $hasStarted = false;
-
     /**
      * Create a new temp database
      *
@@ -73,14 +68,6 @@ class TempDatabase
         return $this->isDBTemp($selected);
     }
 
-    /**
-     * @return bool
-     */
-    public function hasStarted()
-    {
-        return $this->hasStarted;
-    }
-
     /**
      * @return bool
      */
@@ -94,7 +81,6 @@ class TempDatabase
      */
     public function startTransaction()
     {
-        $this->hasStarted = true;
         if (static::getConn()->supportsTransactions()) {
             static::getConn()->transactionStart();
         }
@@ -102,14 +88,28 @@ class TempDatabase
 
     /**
      * Rollback a transaction (or trash all data if the DB doesn't support databases
+     *
+     * @return bool True if successfully rolled back, false otherwise. On error the DB is
+     * killed and must be re-created. Note that calling rollbackTransaction() when there
+     * is no transaction is counted as a failure, user code should either kill or flush the DB
+     * as necessary
      */
     public function rollbackTransaction()
     {
-        if (static::getConn()->supportsTransactions()) {
-            static::getConn()->transactionRollback();
-        } else {
-            $this->hasStarted = false;
-            static::clearAllData();
+        // Ensure a rollback can be performed
+        $success = static::getConn()->supportsTransactions()
+            && static::getConn()->transactionDepth();
+        if (!$success) {
+            return false;
+        }
+        try {
+            // Explicit false = gnostic error from transactionRollback
+            if (static::getConn()->transactionRollback() === false) {
+                return false;
+            }
+            return true;
+        } catch (DatabaseException $ex) {
+            return false;
         }
     }
 
@@ -118,11 +118,14 @@ class TempDatabase
      */
     public function kill()
     {
-        // Delete our temporary database
+        // Nothing to kill
         if (!$this->isUsed()) {
             return;
         }
 
+        // Rollback any transactions (note: Success ignored)
+        $this->rollbackTransaction();
+
         // Check the database actually exists
         $dbConn = $this->getConn();
         $dbName = $dbConn->getSelectedDatabase();
@@ -147,7 +150,6 @@ class TempDatabase
      */
     public function clearAllData()
     {
-        $this->hasStarted = false;
         if (!$this->isUsed()) {
             return;
         }
@@ -205,39 +207,12 @@ class TempDatabase
     }
 
     /**
-     * Clear all temp DBs on this connection
+     * Rebuild all database tables
      *
-     * Note: This will output results to stdout unless suppressOutput
-     * is set on the current db schema
+     * @param array $extraDataObjects
      */
-    public function deleteAll()
+    protected function rebuildTables($extraDataObjects = [])
     {
-        $schema = $this->getConn()->getSchemaManager();
-        foreach ($schema->databaseList() as $dbName) {
-            if ($this->isDBTemp($dbName)) {
-                $schema->dropDatabase($dbName);
-                $schema->alterationMessage("Dropped database \"$dbName\"", 'deleted');
-                flush();
-            }
-        }
-    }
-
-    /**
-     * Reset the testing database's schema.
-     *
-     * @param array $extraDataObjects List of extra dataobjects to build
-     */
-    public function resetDBSchema(array $extraDataObjects = [])
-    {
-        // pgsql doesn't allow schema updates inside transactions
-        // so we need to rollback any transactions before commencing a schema reset
-        if ($this->hasStarted()) {
-            $this->rollbackTransaction();
-        }
-        if (!$this->isUsed()) {
-            return;
-        }
-
         DataObject::reset();
 
         // clear singletons, they're caching old extension info which is used in DatabaseAdmin->doBuild()
@@ -273,4 +248,45 @@ class TempDatabase
         ClassInfo::reset_db_cache();
         DataObject::singleton()->flushCache();
     }
+
+    /**
+     * Clear all temp DBs on this connection
+     *
+     * Note: This will output results to stdout unless suppressOutput
+     * is set on the current db schema
+     */
+    public function deleteAll()
+    {
+        $schema = $this->getConn()->getSchemaManager();
+        foreach ($schema->databaseList() as $dbName) {
+            if ($this->isDBTemp($dbName)) {
+                $schema->dropDatabase($dbName);
+                $schema->alterationMessage("Dropped database \"$dbName\"", 'deleted');
+                flush();
+            }
+        }
+    }
+
+    /**
+     * Reset the testing database's schema.
+     *
+     * @param array $extraDataObjects List of extra dataobjects to build
+     */
+    public function resetDBSchema(array $extraDataObjects = [])
+    {
+        // Skip if no DB
+        if (!$this->isUsed()) {
+            return;
+        }
+
+        try {
+            $this->rebuildTables($extraDataObjects);
+        } catch (DatabaseException $ex) {
+            // In case of error during build force a hard reset
+            // e.g. pgsql doesn't allow schema updates inside transactions
+            $this->kill();
+            $this->build();
+            $this->rebuildTables($extraDataObjects);
+        }
+    }
 }
diff --git a/tests/php/Security/GroupTest.php b/tests/php/Security/GroupTest.php
index 163257602..076e04584 100644
--- a/tests/php/Security/GroupTest.php
+++ b/tests/php/Security/GroupTest.php
@@ -20,6 +20,11 @@ class GroupTest extends FunctionalTest
         TestMember::class
     ];
 
+    protected function setUp()
+    {
+        parent::setUp();
+    }
+
     public function testGroupCodeDefaultsToTitle()
     {
         $g1 = new Group();