A data storage system may implement generating creation performance metrics for a secondary index of a table. Metrics may be collected from different partitions of a table and different partitions of a secondary index in a table store upon initiating creation of the secondary index for the table that utilize provisioned resources for creating the secondary index. The metrics may be analyzed to generate performance metrics for the creation of the table. The performance metrics may be provided to clients of the data store or to monitoring systems. Monitoring systems may send performance event notifications to clients or automatically perform modifications to the provisioned throughput capacity.