Cosharding and randomized cosharding

The technology relates to cosharding tables within a distributed storage system. A data table including one or more rows may be received. Each row in the data table may include an identifier key and pieces of data. Each piece of data in the data table may be indexed into individual rows of an index table, wherein each row in the index table includes data associated with the identifier key of the data table from which the piece of data in the respective row was indexed. The index table may be sharded into splits, wherein the sharding includes assigning each row of the index table into one of the splits based on the identifier key of the data table from which the piece of data in the respective row was indexed. The splits may be stored into two or more portions of the distributed storage system.