diff --git a/code/PostgreSQLDatabase.php b/code/PostgreSQLDatabase.php
index 9cd6f52..7a6befc 100644
--- a/code/PostgreSQLDatabase.php
+++ b/code/PostgreSQLDatabase.php
@@ -872,7 +872,7 @@ class PostgreSQLDatabase extends SS_Database {
 	 *
 	 * @return boolean
 	 */
-	function clear_cached_fieldlist($tableName=false){
+	function clearCachedFieldlist($tableName=false){
 		if($tableName!=false){
 			unset(self::$cached_fieldlists[$tableName]);
 		} else
@@ -1554,15 +1554,13 @@ class PostgreSQLDatabase extends SS_Database {
 	 * helper function in Database?
 	 */
 	public function sqlQueryToString(SQLQuery $sqlQuery) {
-		if (!$sqlQuery->from) return '';
 		$distinct = $sqlQuery->distinct ? "DISTINCT " : "";
 		if($sqlQuery->delete) {
 			$text = "DELETE ";
 		} else if($sqlQuery->select) {
 			$text = "SELECT $distinct" . implode(", ", $sqlQuery->select);
 		}
-		$text .= " FROM " . implode(" ", $sqlQuery->from);
-
+		if($sqlQuery->from) $text .= " FROM " . implode(" ", $sqlQuery->from);
 		if($sqlQuery->where) $text .= " WHERE (" . $sqlQuery->getFilter(). ")";
 		if($sqlQuery->groupby) $text .= " GROUP BY " . implode(", ", $sqlQuery->groupby);
 		if($sqlQuery->having) $text .= " HAVING ( " . implode(" ) AND ( ", $sqlQuery->having) . " )";
@@ -1683,10 +1681,17 @@ class PostgreSQLDatabase extends SS_Database {
 		);
 
 		foreach($result as $row){
-			if($row['table_name']=='SiteTree')
+			if($row['table_name']=='SiteTree') {
 				$showInSearch="AND \"ShowInSearch\"=1 ";
-			else
+			} elseif($row['table_name']=='File') {
+				// File.ShowInSearch was added later, keep the database driver backwards compatible 
+				// by checking for its existence first
+				$fields = $this->fieldList($row['table_name']);
+				if(array_key_exists('ShowInSearch', $fields)) $showInSearch="AND \"ShowInSearch\"=1 ";
+				else $showInSearch='';
+			} else {
 				$showInSearch='';
+			}
 
 			//public function extendedSQL($filter = "", $sort = "", $limit = "", $join = "", $having = ""){
 			$query=singleton($row['table_name'])->extendedSql("\"" . $row['table_name'] . "\".\"" . $row['column_name'] . "\" " .  $this->default_fts_search_method . ' q '  . $showInSearch, '');
@@ -1749,6 +1754,13 @@ class PostgreSQLDatabase extends SS_Database {
 		else
 			return false;
 	}
+	
+	/**
+	 * @deprecated 1.0 Use transactionStart() (method required for 2.4.x)
+	 */
+	public function startTransaction($transaction_mode=false, $session_characteristics=false){
+		$this->transactionStart($transaction_mode, $session_characteristics);
+	}
 
 	/*
 	 * Start a prepared transaction
@@ -1784,6 +1796,13 @@ class PostgreSQLDatabase extends SS_Database {
 			DB::query('ROLLBACK;');
 
 	}
+	
+	/**
+	 * @deprecated 1.0 Use transactionEnd() (method required for 2.4.x)
+	 */
+	public function endTransaction(){
+		$this->transactionEnd();
+	}
 
 	/*
 	 * Commit everything inside this transaction so far
diff --git a/tests/PostgreSQLDatabaseTest.php b/tests/PostgreSQLDatabaseTest.php
new file mode 100644
index 0000000..6c65184
--- /dev/null
+++ b/tests/PostgreSQLDatabaseTest.php
@@ -0,0 +1,48 @@
+<?php
+/**
+ * @package postgresql
+ * @subpackage tests
+ */
+class PostgreSQLDatabaseTest extends SapphireTest {
+	function testReadOnlyTransaction(){
+
+		if(
+			DB::getConn()->supportsTransactions() == true
+			&& DB::getConn() instanceof PostgreSQLDatabase
+		){
+
+			$page=new Page();
+			$page->Title='Read only success';
+			$page->write();
+
+			DB::getConn()->transactionStart('READ ONLY');
+
+			try {
+				$page=new Page();
+				$page->Title='Read only page failed';
+				$page->write();
+			} catch (Exception $e) {
+				//could not write this record
+				//We need to do a rollback or a commit otherwise we'll get error messages
+				DB::getConn()->transactionRollback();
+			}
+
+			DB::getConn()->transactionEnd();
+
+			DataObject::flush_and_destroy_cache();
+
+			$success=DataObject::get('Page', "\"Title\"='Read only success'");
+			$fail=DataObject::get('Page', "\"Title\"='Read only page failed'");
+
+			//This page should be in the system
+			$this->assertTrue(is_object($success) && $success->exists());
+
+			//This page should NOT exist, we had 'read only' permissions
+			$this->assertFalse(is_object($fail) && $fail->exists());
+
+		} else {
+			$this->markTestSkipped('Current database is not PostgreSQL');
+		}
+
+	}
+}
\ No newline at end of file