> [!ExpressionEvaluation] > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_cpu_expressionevaluation.png"></td><td><b>Wait Category</b></td><td>CPU</td></tr><tr><td><b>Mechanism</b></td><td><code>ExecEvalExpr</code></td></tr><tr><td><b>Operations</b></td><td><a href="Operations/Table/SeqScan">SeqScan</a>, <a href="Operations/Index/IndexScan">IndexScan</a></td></tr><tr><td><b>Resources</b></td><td><a href="Resources/CPU">CPU</a></td></tr><tr><td colspan="3">This state indicates <b>Query Logic Complexity</b>. Every time you add a non-trivial operation to a query—like a <code>CASE</code> statement, a regular expression match, or a geometric calculation—Postgres must pass each row through its expression evaluation engine.</td></tr></table>