> [!NOTE] Values Scan > <table> > <tr> > <td width="25%"><img src="assets/ex_values_scan.png"></td> > <td>Scans a set of constant values provided directly in the query (e.g., the <code>VALUES</code> clause). It treats the constant list as a virtual table, allowing it to be filtered, joined, or aggregated like any other physical relation.</td> > </tr> > </table> > > ```sql > -- Scanning a literal list of tuples > EXPLAIN (ANALYZE, COSTS, BUFFERS, VERBOSE) > VALUES (1, 'a'), (2, 'b'); > ``` > > ```text > Values Scan on "*VALUES*" (cost=1.00..1.03 rows=2 width=36) (actual time=1.007..1.008 rows=2 loops=1) > Output: column1, column2 > ``` > > <table> > <tr> > <td rowspan="5" width="25%"><img src="assets/ex_values_scan.svg"></td> > <td><b>Performance</b></td><td>High performance; the tuples are typically stored directly in the query plan and do not require heap access.</td> > </tr> > <tr><td><b>Factors</b></td><td>The number of values provided in the clause.</td></tr> > <tr><td><b>Cost</b></td><td><code>`cpu_tuple_cost * number of values`</code></td></tr> > <tr><td><b>Operates on</b></td><td><a href="Structures/Tuple">Tuple</a></td></tr> > <tr><td><b>Workloads</b></td><td><a href="Workloads/LWLock/Buffers/BufferContent">LWLock: BufferContent</a></td></tr> > <tr><td colspan="3"><b>Description</b>: Scans a list of constant values.</td></tr> > </table>