SET IN_MEMORY_FEDERATION#
Controls whether Querona may use its in-memory federation engine to combine data from several
sources. When ON (the default), the in-memory federator can be applied to a federated statement —
useful when, for example, an in-memory function or an implicit conversion is needed as data moves
between a source and the federator. When OFF, the in-memory federator push-down step is skipped.
Tip
This is an advanced query-planning option, on by default. It affects only how a federated query is planned and executed, not its results — change it for diagnostics or to work around a specific federation issue.
Syntax#
SET IN_MEMORY_FEDERATION { ON | OFF } [;]
Remarks#
When a query spans more than one source, Querona transfers data to a federator to finish the query.
With this option on, the federator can be Querona’s in-memory engine, which is well suited to
applying in-memory functions, filter predicates and implicit conversions to the transferred rows. The
default is ON.
See SET EXTERNAL_FEDERATION and SET SINGLE_SOURCE_FEDERATION for the other federation controls.
Permissions#
Requires membership in the public role.
Examples#
SET IN_MEMORY_FEDERATION OFF;