# Other Result Set Operations ![[assets/ex_subquery.png|256]] **Other Result Set Operations** cover specialized access patterns and scan nodes that don't fit into the standard Table or Index categories. These often involve "virtual" tables generated during query execution. ### The Architectural Role These nodes manage non-persistent data sources. They are responsible for: 1. **CTE Scans**: Reading the result of a Common Table Expression that has been materialized in memory. 2. **Function Scans**: Iterating over the output of a Set-Returning Function (SRF). 3. **Values Scans**: Processing data provided directly in the query (e.g., `VALUES (1, 2), (3, 4)`). ### In the Explain Plan These nodes reveal when Postgres is working with transient data that doesn't exist on disk until the query begins. ```text -> CTE Scan on my_temporary_results (cost=1.00..1.20 rows=10 width=4) CTE my_temporary_results -> Seq Scan on animals (...) ``` --- ![[Operations/Other/CTEScan]] --- ![[Operations/Other/CustomScanForeignScan]] --- ![[Operations/Other/FunctionScan]] --- ![[Operations/Other/SubqueryScan]] --- ![[Operations/Other/ValuesScan]]