Hello, I'm trying to understand this behaviour and the limits of CTE, when they reach the limits, when they cannot receive parameters from a caller, ... I'm running a query on PostgreSQL 10 with a cte. the query runs in ~ 10 seconds. If I add a second CTE with the same query as the previous one and select * from second_cte as query, it now runs in ~ 10 minutes. oversimplified example: 10 seconds version: | WITH cte1 AS (SELECT x,y,z FROM table) SELECT row_number() over(),x,y,z FROM cte1 WHERE x=32; 10 minutes version: | WITH cte1 AS (SELECT x,y,z FROM table), cte2 AS (SELECT row_number() over(),x,y,z FROM cte1) SELECT * FROM cte2 WHERE x=32; The real examples, with query plans: https://explain.dalibo.com/plan/98A https://explain.dalibo.com/plan/o6X4 Thanks for your time, Nicolas Seinlet.
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