A system includes determination of a value identifier for each value of a first table, based on a data dictionary of a second table, generation of a hash function, the hash function mapping, for each row of the first table, one or more value identifiers of one or more columns of the row to a pointer to the row, application of the hash function to one or more value identifiers of a row of a second table, determination of whether the output of the hash function is a valid hash, and, if it is determined that the output of the hash function is a valid hash, determination that the row of the second table is associated with the first table.