Safe Haskell	None
Language	Haskell2010

Rel8.Internal.Query.Materialize

Synopsis

materialize :: Table Expr a => Query a -> (Query a -> Query b) -> Query b

Documentation

materialize :: Table Expr a => Query a -> (Query a -> Query b) -> Query b Source #

materialize takes a Query and fully evaluates it and caches the results thereof, and passes to a continuation a new Query that simply looks up these cached results. It's usually best not to use this and to let the Postgres optimizer decide for itself what's best, but if you know what you're doing this can sometimes help to nudge it in a particular direction.

materialize is currently implemented in terms of Postgres' @WITH syntax, specifically the WITH _ AS MATERIALIZED (_) form introduced in PostgreSQL 12. This means that materialize can only be used with PostgreSQL 12 or newer.