features: materialize oversized result sets into a table#563
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When a result set exceeds the materialization cap it could not be inlined as a literal IN list, so it fell back to re-deriving the producer inline in every consuming sub-query - the same multi-table producer (joins, spatial and temporal filters) re-run once per consumer, dozens of times for a shared set. Materialize such a set once into an indexed, session-independent table and reference it from the consumers as IN (SELECT <value column> FROM <table>), so the producer runs a single time and each consumer only scans the table. The table-backed reference flows into both consumer and producer filters, so a chain of oversized sets references each other's tables. Gated on a dialect capability; dialects without it keep the inline re-evaluation fallback. Table names are unique per request (a per-instance token plus a per-call sequence), so concurrent requests and multiple provider instances on the same database never collide. The names created for a request are collected and dropped when its feature stream completes, on success or error.
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Depends on #562
When a result set exceeds the materialization cap it could not be inlined as a literal IN list, so it fell back to re-deriving the producer inline in every consuming sub-query - the same multi-table producer (joins, spatial and temporal filters) re-run once per consumer, dozens of times for a shared set.
Materialize such a set once into an indexed, session-independent table and reference it from the consumers as
IN (SELECT <value column> FROM <table>), so the producer runs a single time and each consumer only scans the table. The table-backed reference flows into both consumer and producer filters, so a chain of oversized sets references each other's tables. Gated on a dialect capability; dialects without it keep the inline re-evaluation fallback.Table names are unique per request (a per-instance token plus a per-call sequence), so concurrent requests and multiple provider instances on the same database never collide. The names created for a request are collected and dropped when its feature stream completes, on success or error.