Query Pushdown
An optimization technique in federated queries in which the query engine translates operations such as filters, projections, aggregations and joins into statements executable by the source system and delegates them to the source, retrieving only the result set in order to reduce network transfer and local computation load.
Timeline (last 90 days)
Query pushdown means the connector converts the consumer's filtering, projection, aggregation and other operations as much as possible into native queries understandable by the provider's interface, which executes them locally and returns only the result set.
The benefit of query pushdown is a significant reduction in network transmission and local computation overhead, making it especially suitable for wide tables or highly selective queries.
Implementing query pushdown requires the connector to have a capability negotiation mechanism to identify which pushdown operators the provider supports; parts that cannot be pushed down fall back to local execution.
In federated queries, the more thorough the pushdown, the lower the pressure on network transmission and local computation, but the greater the dependence on the source system's query capabilities; conversely, more data must be pulled back for local processing, weakening the value of federation.
All Facts (4)
Query pushdown means the connector converts the consumer's filtering, projection, aggregation and other operations as much as possible into native queries understandable by the provider's interface, which executes them locally and returns only the result set.
50%UnverifiedThe benefit of query pushdown is a significant reduction in network transmission and local computation overhead, making it especially suitable for wide tables or highly selective queries.
50%UnverifiedImplementing query pushdown requires the connector to have a capability negotiation mechanism to identify which pushdown operators the provider supports; parts that cannot be pushed down fall back to local execution.
50%UnverifiedIn federated queries, the more thorough the pushdown, the lower the pressure on network transmission and local computation, but the greater the dependence on the source system's query capabilities; conversely, more data must be pulled back for local processing, weakening the value of federation.
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