diff --git a/tests/cases/Db/BaseDriver.php b/tests/cases/Db/BaseDriver.php
index 46244080..e918fa99 100644
--- a/tests/cases/Db/BaseDriver.php
+++ b/tests/cases/Db/BaseDriver.php
@@ -11,51 +11,69 @@ use JKingWeb\Arsse\Db\Result;
 use JKingWeb\Arsse\Test\DatabaseInformation;
 
 abstract class BaseDriver extends \JKingWeb\Arsse\Test\AbstractTest {
+    protected static $dbInfo;
+    protected static $interface;
     protected $drv;
-    protected $interface;
     protected $create;
     protected $lock;
     protected $setVersion;
-    protected $conf = [
+    protected static $conf = [
         'dbTimeoutExec' => 0.5,
         'dbSQLite3Timeout' => 0,
+      //'dbSQLite3File' => "(temporary file)",
     ];
+
+    public static function setUpBeforeClass() {
+        // establish a clean baseline
+        static::clearData();
+        static::$dbInfo = new DatabaseInformation(static::$implementation);
+        static::setConf(static::$conf);
+        static::$interface = (static::$dbInfo->interfaceConstructor)();
+    }
     
     public function setUp() {
         self::clearData();
-        self::setConf($this->conf);
-        $info = new DatabaseInformation($this->implementation);
-        $this->interface = ($info->interfaceConstructor)();
-        if (!$this->interface) {
-            $this->markTestSkipped("$this->implementation database driver not available");
+        self::setConf(static::$conf);
+        if (!static::$interface) {
+            $this->markTestSkipped(static::$implementation." database driver not available");
         }
-        $this->drv = new $info->driverClass;
-        $this->exec("DROP TABLE IF EXISTS arsse_test");
-        $this->exec("DROP TABLE IF EXISTS arsse_meta");
-        $this->exec("CREATE TABLE arsse_meta(key varchar(255) primary key not null, value text)");
-        $this->exec("INSERT INTO arsse_meta(key,value) values('schema_version','0')");
+        // completely clear the database and ensure the schema version can easily be altered
+        (static::$dbInfo->razeFunction)(static::$interface, [
+            "CREATE TABLE arsse_meta(key varchar(255) primary key not null, value text)",
+            "INSERT INTO arsse_meta(key,value) values('schema_version','0')",
+        ]);
+        // construct a fresh driver for each test
+        $this->drv = new static::$dbInfo->driverClass;
     }
 
     public function tearDown() {
-        self::clearData();
+        // deconstruct the driver
         unset($this->drv);
-        try {
-            $this->exec("ROLLBACK");
-        } catch(\Throwable $e) {
+        if (static::$interface) {
+            // completely clear the database
+            (static::$dbInfo->razeFunction)(static::$interface);
         }
-        $this->exec("DROP TABLE IF EXISTS arsse_meta");
-        $this->exec("DROP TABLE IF EXISTS arsse_test");
+        self::clearData();
     }
 
-    protected function exec(string $q): bool {
+    public static function tearDownAfterClass() {
+        static::$implementation = null;
+        static::$dbInfo = null;
+        self::clearData();
+    }
+
+    protected function exec($q): bool {
         // PDO implementation
-        $this->interface->exec($q);
+        $q = (!is_array($q)) ? [$q] : $q;
+        foreach ($q as $query) {
+            static::$interface->exec((string) $query);
+        }
         return true;
     }
 
     protected function query(string $q) {
         // PDO implementation
-        return $this->interface->query($q)->fetchColumn();
+        return static::$interface->query($q)->fetchColumn();
     }
 
     # TESTS 
@@ -87,7 +105,8 @@ abstract class BaseDriver extends \JKingWeb\Arsse\Test\AbstractTest {
         $this->exec($this->create);
         $this->exec($this->lock);
         $this->assertException("general", "Db", "ExceptionTimeout");
-        $this->drv->exec($this->lock);
+        $lock = is_array($this->lock) ? implode("; ",$this->lock) : $this->lock;
+        $this->drv->exec($lock);
     }
 
     public function testExecConstraintViolation() {
@@ -115,7 +134,8 @@ abstract class BaseDriver extends \JKingWeb\Arsse\Test\AbstractTest {
         $this->exec($this->create);
         $this->exec($this->lock);
         $this->assertException("general", "Db", "ExceptionTimeout");
-        $this->drv->exec($this->lock);
+        $lock = is_array($this->lock) ? implode("; ",$this->lock) : $this->lock;
+        $this->drv->exec($lock);
     }
 
     public function testQueryConstraintViolation() {
@@ -342,12 +362,20 @@ abstract class BaseDriver extends \JKingWeb\Arsse\Test\AbstractTest {
         $this->assertSame(1, $this->drv->schemaVersion());
         $this->drv->exec(str_replace("#", "2", $this->setVersion));
         $this->assertSame(2, $this->drv->schemaVersion());
+        // SQLite is unaffected by the removal of the metadata table; other backends are
+        // in neither case should a query for the schema version produce an error, however
+        $this->exec("DROP TABLE IF EXISTS arsse_meta");
+        $exp = (static::$dbInfo->backend == "SQLite 3") ? 2 : 0;
+        $this->assertSame($exp, $this->drv->schemaVersion());
     }
 
     public function testLockTheDatabase() {
+        // PostgreSQL doesn't actually lock the whole database, only the metadata table
+        // normally the application will first query this table to ensure the schema version is correct,
+        // so the effect is usually the same
         $this->drv->savepointCreate(true);
         $this->assertException();
-        $this->exec($this->create);
+        $this->exec(str_replace("#", "3", $this->setVersion));
     }
 
     public function testUnlockTheDatabase() {
@@ -355,6 +383,6 @@ abstract class BaseDriver extends \JKingWeb\Arsse\Test\AbstractTest {
         $this->drv->savepointRelease();
         $this->drv->savepointCreate(true);
         $this->drv->savepointUndo();
-        $this->assertTrue($this->exec($this->create));
+        $this->assertTrue($this->exec(str_replace("#", "3", $this->setVersion)));
     }
 }
diff --git a/tests/cases/Db/BaseResult.php b/tests/cases/Db/BaseResult.php
index 96dae042..de1ddf22 100644
--- a/tests/cases/Db/BaseResult.php
+++ b/tests/cases/Db/BaseResult.php
@@ -10,29 +10,45 @@ use JKingWeb\Arsse\Db\Result;
 use JKingWeb\Arsse\Test\DatabaseInformation;
 
 abstract class BaseResult extends \JKingWeb\Arsse\Test\AbstractTest {
+    protected static $dbInfo;
+    protected static $interface;
     protected $resultClass;
     protected $stringOutput;
-    protected $interface;
 
-    abstract protected function exec(string $q);
     abstract protected function makeResult(string $q): array;
 
+    public static function setUpBeforeClass() {
+        // establish a clean baseline
+        static::clearData();
+        static::$dbInfo = new DatabaseInformation(static::$implementation);
+        static::setConf();
+        static::$interface = (static::$dbInfo->interfaceConstructor)();
+    }
+    
     public function setUp() {
         self::clearData();
         self::setConf();
-        $info = new DatabaseInformation($this->implementation);
-        $this->interface = ($info->interfaceConstructor)();
-        if (!$this->interface) {
-            $this->markTestSkipped("$this->implementation database driver not available");
+        if (!static::$interface) {
+            $this->markTestSkipped(static::$implementation." database driver not available");
         }
-        $this->resultClass = $info->resultClass;
-        $this->stringOutput = $info->stringOutput;
-        $this->exec("DROP TABLE IF EXISTS arsse_meta");
+        // completely clear the database
+        (static::$dbInfo->razeFunction)(static::$interface);
+        $this->resultClass = static::$dbInfo->resultClass;
+        $this->stringOutput = static::$dbInfo->stringOutput;
     }
 
     public function tearDown() {
+        if (static::$interface) {
+            // completely clear the database
+            (static::$dbInfo->razeFunction)(static::$interface);
+        }
+        self::clearData();
+    }
+
+    public static function tearDownAfterClass() {
+        static::$implementation = null;
+        static::$dbInfo = null;
         self::clearData();
-        $this->exec("DROP TABLE IF EXISTS arsse_meta");
     }
 
     public function testConstructResult() {
diff --git a/tests/cases/Db/BaseStatement.php b/tests/cases/Db/BaseStatement.php
index 4369f7ac..c7da01ee 100644
--- a/tests/cases/Db/BaseStatement.php
+++ b/tests/cases/Db/BaseStatement.php
@@ -10,29 +10,45 @@ use JKingWeb\Arsse\Db\Statement;
 use JKingWeb\Arsse\Test\DatabaseInformation;
 
 abstract class BaseStatement extends \JKingWeb\Arsse\Test\AbstractTest {
+    protected static $dbInfo;
+    protected static $interface;
     protected $statementClass;
     protected $stringOutput;
-    protected $interface;
 
-    abstract protected function exec(string $q);
     abstract protected function makeStatement(string $q, array $types = []): array;
     abstract protected function decorateTypeSyntax(string $value, string $type): string;
 
+    public static function setUpBeforeClass() {
+        // establish a clean baseline
+        static::clearData();
+        static::$dbInfo = new DatabaseInformation(static::$implementation);
+        static::setConf();
+        static::$interface = (static::$dbInfo->interfaceConstructor)();
+    }
+    
     public function setUp() {
         self::clearData();
         self::setConf();
-        $info = new DatabaseInformation($this->implementation);
-        $this->interface = ($info->interfaceConstructor)();
-        if (!$this->interface) {
-            $this->markTestSkipped("$this->implementation database driver not available");
+        if (!static::$interface) {
+            $this->markTestSkipped(static::$implementation." database driver not available");
         }
-        $this->statementClass = $info->statementClass;
-        $this->stringOutput = $info->stringOutput;
-        $this->exec("DROP TABLE IF EXISTS arsse_meta");
+        // completely clear the database
+        (static::$dbInfo->razeFunction)(static::$interface);
+        $this->statementClass = static::$dbInfo->statementClass;
+        $this->stringOutput = static::$dbInfo->stringOutput;
     }
 
     public function tearDown() {
-        $this->exec("DROP TABLE IF EXISTS arsse_meta");
+        if (static::$interface) {
+            // completely clear the database
+            (static::$dbInfo->razeFunction)(static::$interface);
+        }
+        self::clearData();
+    }
+
+    public static function tearDownAfterClass() {
+        static::$implementation = null;
+        static::$dbInfo = null;
         self::clearData();
     }
 
@@ -56,7 +72,7 @@ abstract class BaseStatement extends \JKingWeb\Arsse\Test\AbstractTest {
 
     /** @dataProvider provideBinaryBindings */
     public function testHandleBinaryData($value, string $type, string $exp) {
-        if (in_array($this->implementation, ["PostgreSQL", "PDO PostgreSQL"])) {
+        if (in_array(static::$implementation, ["PostgreSQL", "PDO PostgreSQL"])) {
             $this->markTestSkipped("Correct handling of binary data with PostgreSQL is currently unknown");
         }
         if ($exp=="null") {
diff --git a/tests/cases/Db/PostgreSQL/TestDatabase.php b/tests/cases/Db/PostgreSQL/TestDatabase.php
new file mode 100644
index 00000000..5ba3d04d
--- /dev/null
+++ b/tests/cases/Db/PostgreSQL/TestDatabase.php
@@ -0,0 +1,19 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse\TestCase\Db\PosgreSQL;
+
+/** 
+ * @covers \JKingWeb\Arsse\Database<extended>
+ * @covers \JKingWeb\Arsse\Misc\Query<extended>
+ */
+class TestDatabase extends \JKingWeb\Arsse\TestCase\Database\Base {
+    protected static $implementation = "PDO PostgreSQL";
+
+    protected function nextID(string $table): int {
+        return static::$drv->query("SELECT select cast(last_value as bigint) + 1 from pg_sequences where sequencename = '{$table}_id_seq'")->getValue();
+    }
+}
diff --git a/tests/cases/Db/PostgreSQL/TestDriver.php b/tests/cases/Db/PostgreSQL/TestDriver.php
index 497488f7..63e73c6b 100644
--- a/tests/cases/Db/PostgreSQL/TestDriver.php
+++ b/tests/cases/Db/PostgreSQL/TestDriver.php
@@ -11,13 +11,8 @@ namespace JKingWeb\Arsse\TestCase\Db\PostgreSQL;
  * @covers \JKingWeb\Arsse\Db\PDODriver
  * @covers \JKingWeb\Arsse\Db\PDOError */
 class TestDriver extends \JKingWeb\Arsse\TestCase\Db\BaseDriver {
-    protected $implementation = "PDO PostgreSQL";
+    protected static $implementation = "PDO PostgreSQL";
     protected $create = "CREATE TABLE arsse_test(id bigserial primary key)";
-    protected $lock = "BEGIN; LOCK TABLE arsse_test IN EXCLUSIVE MODE NOWAIT";
+    protected $lock = ["BEGIN", "LOCK TABLE arsse_test IN EXCLUSIVE MODE NOWAIT"];
     protected $setVersion = "UPDATE arsse_meta set value = '#' where key = 'schema_version'";
-
-    public function tearDown() {
-        parent::tearDown();
-        unset($this->interface);
-    }
 }
diff --git a/tests/cases/Db/PostgreSQL/TestStatement.php b/tests/cases/Db/PostgreSQL/TestStatement.php
index 2c8586fc..cfa42b47 100644
--- a/tests/cases/Db/PostgreSQL/TestStatement.php
+++ b/tests/cases/Db/PostgreSQL/TestStatement.php
@@ -10,19 +10,10 @@ namespace JKingWeb\Arsse\TestCase\Db\PostgreSQL;
  * @covers \JKingWeb\Arsse\Db\PDOStatement<extended>
  * @covers \JKingWeb\Arsse\Db\PDOError */
 class TestStatement extends \JKingWeb\Arsse\TestCase\Db\BaseStatement {
-    protected $implementation = "PDO PostgreSQL";
-
-    public function tearDown() {
-        parent::tearDown();
-        unset($this->interface);
-    }
-
-    protected function exec(string $q) {
-        $this->interface->exec($q);
-    }
+    protected static $implementation = "PDO PostgreSQL";
 
     protected function makeStatement(string $q, array $types = []): array {
-        return [$this->interface, $this->interface->prepare($q), $types];
+        return [static::$interface, static::$interface->prepare($q), $types];
     }
 
     protected function decorateTypeSyntax(string $value, string $type): string {
diff --git a/tests/cases/Db/SQLite3/TestDriver.php b/tests/cases/Db/SQLite3/TestDriver.php
index df802106..9b2348a6 100644
--- a/tests/cases/Db/SQLite3/TestDriver.php
+++ b/tests/cases/Db/SQLite3/TestDriver.php
@@ -10,92 +10,39 @@ namespace JKingWeb\Arsse\TestCase\Db\SQLite3;
  * @covers \JKingWeb\Arsse\Db\SQLite3\Driver<extended>
  * @covers \JKingWeb\Arsse\Db\SQLite3\ExceptionBuilder */
 class TestDriver extends \JKingWeb\Arsse\TestCase\Db\BaseDriver {
-    protected $implementation = "SQLite 3";
+    protected static $implementation = "SQLite 3";
     protected $create = "CREATE TABLE arsse_test(id integer primary key)";
     protected $lock = "BEGIN EXCLUSIVE TRANSACTION";
     protected $setVersion = "PRAGMA user_version=#";
     protected static $file;
 
     public static function setUpBeforeClass() {
-        self::$file = tempnam(sys_get_temp_dir(), 'ook');
+        // create a temporary database file rather than using a memory database
+        // some tests require one connection to block another, so a memory database is not suitable
+        static::$file = tempnam(sys_get_temp_dir(), 'ook');
+        static::$conf['dbSQLite3File'] = static::$file;
+        parent::setUpBeforeclass();
     }
 
     public static function tearDownAfterClass() {
-        @unlink(self::$file);
-        self::$file = null;
-    }
-    
-    public function setUp() {
-        $this->conf['dbSQLite3File'] = self::$file;
-        parent::setUp();
-        $this->exec("PRAGMA user_version=0");
+        if (static::$interface) {
+            static::$interface->close();
+        }
+        parent::tearDownAfterClass();
+        @unlink(static::$file);
+        static::$file = null;
     }
 
-    public function tearDown() {
-        parent::tearDown();
-        $this->exec("PRAGMA user_version=0");
-        $this->interface->close();
-        unset($this->interface);
-    }
-
-    protected function exec(string $q): bool {
-        $this->interface->exec($q);
+    protected function exec($q): bool {
+        // SQLite's implementation coincidentally matches PDO's, but we reproduce it here for correctness' sake
+        $q = (!is_array($q)) ? [$q] : $q;
+        foreach ($q as $query) {
+            static::$interface->exec((string) $query);
+        }
         return true;
     }
 
     protected function query(string $q) {
-        return $this->interface->querySingle($q);
-    }
-
-    public function provideDrivers() {
-        self::clearData();
-        self::setConf([
-            'dbTimeoutExec' => 0.5,
-            'dbSQLite3Timeout' => 0,
-            'dbSQLite3File' => tempnam(sys_get_temp_dir(), 'ook'),
-        ]);
-        $i = $this->provideDbInterfaces();
-        $d = $this->provideDbDrivers();
-        $pdoExec = function (string $q) {
-            $this->interface->exec($q);
-            return true;
-        };
-        $pdoQuery = function (string $q) {
-            return $this->interface->query($q)->fetchColumn();
-        };
-        return [
-            'SQLite 3' => [
-                $i['SQLite 3']['interface'], 
-                $d['SQLite 3'], 
-                "CREATE TABLE arsse_test(id integer primary key)", 
-                "BEGIN EXCLUSIVE TRANSACTION",
-                "PRAGMA user_version=#",
-                function (string $q) {
-                    $this->interface->exec($q);
-                    return true;
-                },
-                function (string $q) {
-                    return $this->interface->querySingle($q);
-                },
-            ],
-            'PDO SQLite 3' => [
-                $i['PDO SQLite 3']['interface'], 
-                $d['PDO SQLite 3'], 
-                "CREATE TABLE arsse_test(id integer primary key)", 
-                "BEGIN EXCLUSIVE TRANSACTION",
-                "PRAGMA user_version=#",
-                $pdoExec,
-                $pdoQuery,
-            ],
-            'PDO PostgreSQL' => [
-                $i['PDO PostgreSQL']['interface'], 
-                $d['PDO PostgreSQL'], 
-                "CREATE TABLE arsse_test(id bigserial primary key)", 
-                "BEGIN; LOCK TABLE arsse_test IN EXCLUSIVE MODE NOWAIT",
-                "UPDATE arsse_meta set value = '#' where key = 'schema_version'",
-                $pdoExec,
-                $pdoQuery,
-            ],
-        ];
+        return static::$interface->querySingle($q);
     }
 }
diff --git a/tests/cases/Db/SQLite3/TestResult.php b/tests/cases/Db/SQLite3/TestResult.php
index 2f655e7e..4109b8f1 100644
--- a/tests/cases/Db/SQLite3/TestResult.php
+++ b/tests/cases/Db/SQLite3/TestResult.php
@@ -12,22 +12,19 @@ use JKingWeb\Arsse\Test\DatabaseInformation;
  * @covers \JKingWeb\Arsse\Db\SQLite3\Result<extended> 
  */
 class TestResult extends \JKingWeb\Arsse\TestCase\Db\BaseResult {
-    protected $implementation = "SQLite 3";
+    protected static $implementation = "SQLite 3";
 
-    public function tearDown() {
-        parent::tearDown();
-        $this->interface->close();
-        unset($this->interface);
-    }
-
-    protected function exec(string $q) {
-        $this->interface->exec($q);
+    public static function tearDownAfterClass() {
+        if (static::$interface) {
+            static::$interface->close();
+        }
+        parent::tearDownAfterClass();
     }
 
     protected function makeResult(string $q): array {
-        $set = $this->interface->query($q);
-        $rows = $this->interface->changes();
-        $id = $this->interface->lastInsertRowID();
+        $set = static::$interface->query($q);
+        $rows = static::$interface->changes();
+        $id = static::$interface->lastInsertRowID();
         return [$set, [$rows, $id]];
     }
 }
diff --git a/tests/cases/Db/SQLite3/TestStatement.php b/tests/cases/Db/SQLite3/TestStatement.php
index fc06dbd0..1684e832 100644
--- a/tests/cases/Db/SQLite3/TestStatement.php
+++ b/tests/cases/Db/SQLite3/TestStatement.php
@@ -10,20 +10,15 @@ namespace JKingWeb\Arsse\TestCase\Db\SQLite3;
  * @covers \JKingWeb\Arsse\Db\SQLite3\Statement<extended>
  * @covers \JKingWeb\Arsse\Db\SQLite3\ExceptionBuilder */
 class TestStatement extends \JKingWeb\Arsse\TestCase\Db\BaseStatement {
-    protected $implementation = "SQLite 3";
+    protected static $implementation = "SQLite 3";
 
-    public function tearDown() {
-        parent::tearDown();
-        $this->interface->close();
-        unset($this->interface);
-    }
-
-    protected function exec(string $q) {
-        $this->interface->exec($q);
+    public static function tearDownAfterClass() {
+        static::$interface->close();
+        parent::tearDownAfterClass();
     }
 
     protected function makeStatement(string $q, array $types = []): array {
-        return [$this->interface, $this->interface->prepare($q), $types];
+        return [static::$interface, static::$interface->prepare($q), $types];
     }
 
     protected function decorateTypeSyntax(string $value, string $type): string {
diff --git a/tests/cases/Db/SQLite3PDO/TestDriver.php b/tests/cases/Db/SQLite3PDO/TestDriver.php
index 73ae773e..475d5756 100644
--- a/tests/cases/Db/SQLite3PDO/TestDriver.php
+++ b/tests/cases/Db/SQLite3PDO/TestDriver.php
@@ -11,30 +11,23 @@ namespace JKingWeb\Arsse\TestCase\Db\SQLite3PDO;
  * @covers \JKingWeb\Arsse\Db\PDODriver
  * @covers \JKingWeb\Arsse\Db\PDOError */
 class TestDriver extends \JKingWeb\Arsse\TestCase\Db\BaseDriver {
-    protected $implementation = "PDO SQLite 3";
+    protected static $implementation = "PDO SQLite 3";
     protected $create = "CREATE TABLE arsse_test(id integer primary key)";
     protected $lock = "BEGIN EXCLUSIVE TRANSACTION";
     protected $setVersion = "PRAGMA user_version=#";
     protected static $file;
 
     public static function setUpBeforeClass() {
-        self::$file = tempnam(sys_get_temp_dir(), 'ook');
+        // create a temporary database file rather than using a memory database
+        // some tests require one connection to block another, so a memory database is not suitable
+        static::$file = tempnam(sys_get_temp_dir(), 'ook');
+        static::$conf['dbSQLite3File'] = static::$file;
+        parent::setUpBeforeclass();
     }
 
     public static function tearDownAfterClass() {
+        parent::tearDownAfterClass();
         @unlink(self::$file);
         self::$file = null;
     }
-    
-    public function setUp() {
-        $this->conf['dbSQLite3File'] = self::$file;
-        parent::setUp();
-        $this->exec("PRAGMA user_version=0");
-    }
-
-    public function tearDown() {
-        parent::tearDown();
-        $this->exec("PRAGMA user_version=0");
-        unset($this->interface);
-    }
 }
diff --git a/tests/cases/Db/SQLite3PDO/TestStatement.php b/tests/cases/Db/SQLite3PDO/TestStatement.php
index 74f05f19..9e2e06c6 100644
--- a/tests/cases/Db/SQLite3PDO/TestStatement.php
+++ b/tests/cases/Db/SQLite3PDO/TestStatement.php
@@ -10,19 +10,10 @@ namespace JKingWeb\Arsse\TestCase\Db\SQLite3PDO;
  * @covers \JKingWeb\Arsse\Db\PDOStatement<extended>
  * @covers \JKingWeb\Arsse\Db\PDOError */
 class TestStatement extends \JKingWeb\Arsse\TestCase\Db\BaseStatement {
-    protected $implementation = "PDO SQLite 3";
-
-    public function tearDown() {
-        parent::tearDown();
-        unset($this->interface);
-    }
-
-    protected function exec(string $q) {
-        $this->interface->exec($q);
-    }
+    protected static $implementation = "PDO SQLite 3";
 
     protected function makeStatement(string $q, array $types = []): array {
-        return [$this->interface, $this->interface->prepare($q), $types];
+        return [static::$interface, static::$interface->prepare($q), $types];
     }
 
     protected function decorateTypeSyntax(string $value, string $type): string {
diff --git a/tests/cases/Db/TestResultPDO.php b/tests/cases/Db/TestResultPDO.php
index f4d2eec7..f1792f84 100644
--- a/tests/cases/Db/TestResultPDO.php
+++ b/tests/cases/Db/TestResultPDO.php
@@ -12,41 +12,30 @@ use JKingWeb\Arsse\Test\DatabaseInformation;
  * @covers \JKingWeb\Arsse\Db\PDOResult<extended> 
  */
 class TestResultPDO extends \JKingWeb\Arsse\TestCase\Db\BaseResult {
-    protected static $firstAvailableDriver;
+    protected static $implementation;
 
     public static function setUpBeforeClass() {
         self::setConf();
         // we only need to test one PDO implementation (they all use the same result class), so we find the first usable one
         $drivers = DatabaseInformation::listPDO();
-        self::$firstAvailableDriver = $drivers[0];
+        self::$implementation = $drivers[0];
         foreach ($drivers as $driver) {
             $info = new DatabaseInformation($driver);
             $interface = ($info->interfaceConstructor)();
             if ($interface) {
-                self::$firstAvailableDriver = $driver;
+                self::$implementation = $driver;
                 break;
             }
         }
-    }
-    
-    public function setUp() {
-        $this->implementation = self::$firstAvailableDriver;
-        parent::setUp();
-    }
-
-    public function tearDown() {
-        parent::tearDown();
-        unset($this->interface);
-    }
-
-    protected function exec(string $q) {
-        $this->interface->exec($q);
+        unset($interface);
+        unset($info);
+        parent::setUpBeforeClass();
     }
 
     protected function makeResult(string $q): array {
-        $set = $this->interface->query($q);
+        $set = static::$interface->query($q);
         $rows = $set->rowCount();
-        $id = $this->interface->lastInsertID();
+        $id = static::$interface->lastInsertID();
         return [$set, [$rows, $id]];
     }
 }
diff --git a/tests/lib/DatabaseInformation.php b/tests/lib/DatabaseInformation.php
index 4b1d950e..0ec4d1d2 100644
--- a/tests/lib/DatabaseInformation.php
+++ b/tests/lib/DatabaseInformation.php
@@ -59,7 +59,12 @@ class DatabaseInformation {
                 $tables = $db->query($listTables)->getAll();
                 $tables = sizeof($tables) ? array_column($tables, "name") : [];
             } elseif ($db instanceof \PDO) {
-                $tables = $db->query($listTables)->fetchAll(\PDO::FETCH_ASSOC);
+                retry:
+                try {
+                    $tables = $db->query($listTables)->fetchAll(\PDO::FETCH_ASSOC);
+                } catch (\PDOException $e) {
+                    goto retry;
+                }
                 $tables = sizeof($tables) ? array_column($tables, "name") : [];
             } else {
                 $tables = [];
@@ -72,6 +77,11 @@ class DatabaseInformation {
             return $tables;
         };
         $sqlite3TruncateFunction = function($db, array $afterStatements = []) use ($sqlite3TableList) {
+            // rollback any pending transaction
+            try {
+                $db->exec("ROLLBACK");
+            } catch(\Throwable $e) {
+            }
             foreach ($sqlite3TableList($db) as $table) {
                 if ($table == "arsse_meta") {
                     $db->exec("DELETE FROM $table where key <> 'schema_version'");
@@ -84,6 +94,11 @@ class DatabaseInformation {
             }
         };
         $sqlite3RazeFunction = function($db, array $afterStatements = []) use ($sqlite3TableList) {
+            // rollback any pending transaction
+            try {
+                $db->exec("ROLLBACK");
+            } catch(\Throwable $e) {
+            }
             $db->exec("PRAGMA foreign_keys=0");
             foreach ($sqlite3TableList($db) as $table) {
                 $db->exec("DROP TABLE IF EXISTS $table");
@@ -163,7 +178,12 @@ class DatabaseInformation {
                     return $d;
                 },
                 'truncateFunction' => function($db, array $afterStatements = []) use ($pgObjectList) {
-                    foreach ($objectList($db) as $obj) {
+                    // rollback any pending transaction
+                    try {
+                        $db->exec("ROLLBACK");
+                    } catch(\Throwable $e) {
+                    }
+                    foreach ($pgObjectList($db) as $obj) {
                         if ($obj['type'] != "TABLE") {
                             continue;
                         } elseif ($obj['name'] == "arsse_meta") {
@@ -177,8 +197,8 @@ class DatabaseInformation {
                     }
                 },
                 'razeFunction' => function($db, array $afterStatements = []) use ($pgObjectList) {
-                    foreach ($objectList($db) as $obj) {
-                        $db->exec("DROP {$obj['type']} {$obj['name']} IF EXISTS cascade");
+                    foreach ($pgObjectList($db) as $obj) {
+                        $db->exec("DROP {$obj['type']} IF EXISTS {$obj['name']} cascade");
                         
                     }
                     foreach ($afterStatements as $st) {