A table-level histogram is maintained incrementally without requiring rescanning of the entire table when new data values are added to the table. A table has multiple partitions of data values. A histogram for data values of the partitions is generated. When a new partition of data values is added to the table, a histogram for only the new partition is generated. To generate a histogram for the entire table, the histograms for the previously generated and newly added partitions are used without needing to refer to the underlying data. A similar approach is applicable when modifying data values in a partition.