Abstract: Different types of index structures are used for a replica group of a database. A leader node of a replica group performs receives updates to a copy of the database using a first type of index structure. A follower node performs updates received from the leader node as a log of updates to a copy of the database in an external storage system when a size of the received updates exceeds a threshold. The follower node performs requests to read data from the database using the copy in the external storage.

Abstract: Throughput capacity may be changed to sustain throughput for accessing individual items in a database. A table hosted at storage nodes that provide access to the table in a database may be identified as allocated with a client-specified throughput capacity for accessing the table. Performance of access requests to the table at the storage nodes may be tracked. Based on the performance of the access requests, a change may be determined that modifies a throughput capacity for the table to sustain a guaranteed throughput for each access request independent of other access requests received for the table.

Abstract: Techniques are described for monitoring and enabling access to information about key access patterns for nonrelational database tables managed by a nonrelational database service of a service provider network. Storage nodes store data as key-value pairs (or key-document pairs), where the records or documents of a database are addressed by a unique key for each record. The storage nodes over time receive requests to perform various operations (for example, to get, put, update, or delete data in a table) associated with records stored by the storage nodes. The storage nodes collect information indicating a frequency with which such requests are received for each key for which a storage node is responsible. This frequency information for each key can be normalized relative to a maximum frequency supported by the storage nodes to obtain an access frequency score, where the maximum frequency indicates a frequency at which additional requests to the storage node may be throttled.