> [!DSMFillZero] > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_io_dsmfillzero.png"></td><td><b>Wait Category</b></td><td>IO</td></tr><tr><td><b>Mechanism</b></td><td><code>dsm_create</code></td></tr><tr><td><b>Operations</b></td><td><a href="Operations/Table/SeqScan">SeqScan</a>, <a href="Operations/ResultSet/HashJoin">HashJoin</a></td></tr><tr><td><b>Resources</b></td><td><a href="Resources/RAM">Memory</a>, <a href="Resources/CPU">CPU</a></td></tr><tr><td colspan="3">This wait event represents a <b>Memory Allocation Barrier</b>. When a parallel query starts, the leader backend must create one or more DSM segments to facilitate communication with its workers.</td></tr></table>