Techniques for storage optimization in a distributed object store are described. A storage optimization service of a provider network monitors changes to data objects in a distributed object store that are part of a data lake and are referenced by a table index. The storage optimization service determines whether particular storage optimizations involving the data objects would be beneficial, prioritizes the ordering of these optimizations with a focus on performing impactful optimizations first, while intelligently scheduling the optimizations to avoid overutilization of available resources.