openrat-cms

commit df501ab9566f8a39510759751a6e9cdfbe2dc3db
parent 87616f63f47b1036e44d52b3470a88e2da728150
Author: Jan Dankert <devnull@localhost>
Date:   Fri,  9 Feb 2018 21:59:27 +0100

NICHT autocommit=false setzen. Denn damit erzeugt ein SELECT bei Isolation-Level REPEATABLE_READ (Standard in Mysql 5.x) eine Transaktion. Wenn diese offen bleibt und die Verbindung wiederverwendet wird, liest ein SELECT ältere Werte, alsl in der Datenbank stehen. Abgesehen davon, dass alle Datenbankprozesse mit offenen Transaktionen belegt werden und die Resourcen schnell erschöpft sind.

Diffstat:
modules/database/driver/PDODriver.class.php
 | 
19
+++++++++++++++----

1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/modules/database/driver/PDODriver.class.php b/modules/database/driver/PDODriver.class.php
@@ -75,17 +75,28 @@ class PDODriver
 				$options[substr($c,8)] = $conf[$c];
 
 		if	( $conf['persistent'])
+		    // From the docs:
+		    // "Many web applications will benefit from making persistent connections to database servers.
+		    //  Persistent connections are not closed at the end of the script, but are cached and re-used
+		    //  when another script requests a connection using the same credentials."
+		    // "The persistent connection cache allows you to avoid the overhead of establishing a new
+		    // connection every time a script needs to talk to a database, resulting in a faster web application."
 			$options[ PDO::ATTR_PERSISTENT ] = true;
 
-		//if	( !$conf['prepare']) <- unused...
 		// From the docs:
-		// try to use native prepared statements (if FALSE).
-		// It will always fall back to emulating the prepared statement if the driver cannot successfully prepare the current query
+		// "try to use native prepared statements (if FALSE).
+		//  It will always fall back to emulating the prepared statement if the driver cannot successfully prepare the current query"
 		$options[ PDO::ATTR_EMULATE_PREPARES ] = false;
 		
 		// Convert numeric values to strings when fetching => NO
 		$options[ PDO::ATTR_STRINGIFY_FETCHES ] = false;
-		$options[ PDO::ATTR_AUTOCOMMIT ] = false;
+
+		// From the docs:
+		// "If this value is FALSE, PDO attempts to disable autocommit so that the connection begins a transaction."
+        // We do NOT need transactions for reading actions (GET requests).
+        // We are opening a transaction with PDO::beginTransaction at the beginning of a  POST-request.
+        // do NOT set this to false, otherwise there will be left open transactions.
+		//$options[ PDO::ATTR_AUTOCOMMIT ] = true;
 			
 		// We like Exceptions
 		$options[ PDO::ERRMODE_EXCEPTION ] = true;