A seed value assigned to a database table is determined. Numerically ordered invocation numbers are determined. Unordered pseudorandom numbers are generated based on the seed value and the invocation numbers to index temporally ordered data changes to the database table. It is determined whether the total number of yet-to-be-saved pseudorandom numbers reaches a maximum total number threshold. If so, the yet-to-be-saved pseudorandom numbers and a sequence of corresponding invocation numbers are saved in a sync table.