Limited cross-shard queries

SPQR is optimized for single-shard OLTP queries. But SPQR router supports limited subset of cross-shard queries. For example, SELECT * FROM without WHERE clause or DDL commands. This is made from best-effort logic in a non-disruptive and non-consistent way and is used mainly for testing purposes. Please be carefull using this feature in production, cross-shard snapshot will be inconsistent.

You can force disable this feature by setting a query_routing.default_route_behaviour to BLOCK in your router config file.

We have long-term plans to support routing queries for 2 or more shards efficiently.