Abstract: Intelligent query routing may be performed across shards of a scalable database table. A router of a database system may receive an access request directed to one or more database tables. The router may evaluate the access request with respect to metadata obtained for the database tables to determine an assignment distribution of computing resources of the database system to data that can satisfy the access request. The router can select planning locations to perform the access request based on the assignment distribution of the computing resources. The router can cause the access request to be performed according to planning at the selected planning locations.

Abstract: Techniques for fast online scaling of a database via a split architecture including decoupled storage and compute tiers in a database service are described. A cluster of database (DB) nodes is scaled to add a new DB node. The scaling includes determining a split for data of a first volume managed by an existing DB node. A second DB node is obtained, and the first volume is cloned according to a lightweight copy technique to yield a second volume for use by the second DB node. After the cloning, a set of database modifications are applied to the second volume based on modifications caused by database traffic received by the first DB node, involving the the volume, during the cloning of the first volume. Each DB node may drop the portion of the volume that it does not need according to the split.