title: How to increase `maxTransactionSize` for Streaming Transactions in arangodb-php
body: <p>The documentation says to pass as transaction-attribute (the call to <code>/begin</code>):</p>
  
  <blockquote>
    <p>maxTransactionSize: Transaction size limit in bytes. Honored by the RocksDB storage engine only.</p>
  </blockquote>
  
  <p>I manage to do just that, despite the fact that the <code>php</code>-client ignores the attribute, by setting it manually before I hand the transaction-instance over to the handler:</p>
  
  <pre><code> $trx-&gt;set('maxTransactionSize', $config['maxTransactionSize'])
  </code></pre>
  
  <p>This is <code>var_dump</code> of the transaction attributes (<code>$trx-&gt;attributes</code>) directly prior to the call to <code>begin</code>:</p>
  
  <pre class="lang-php prettyprint-override"><code>includes/libs/arangodb/lib/ArangoDBClient/StreamingTransactionHandler.php:50:
  array(2) {
    'collections' =&gt;
      array(3) {
        'read' =&gt;
         array(0) {
        }
        'write' =&gt;
         array(0) {
        }
        'exclusive' =&gt;
         array(1) {
           [0] =&gt;
            string(7) "actions"
         }
      }
    'maxTransactionSize' =&gt;
    int(536870912)
  }
  </code></pre>
  
  <p>But the transaction fails with:</p>
  
  <blockquote>
    <p>error : AQL: aborting transaction because maximal transaction size limit of 134217728 bytes is reached (while executing)</p>
  </blockquote>
  
  <p>What am I missing/doing wrong?</p>
  
  <p>I tested this on 3.5.4 and 3.6.1, with the same result.</p>