Append several tables, keeping the sort that is present inside the input tables.
The MergeSort Action takes as input many SORTED tables (on the different input pins) and it gives as output one SORTED table that includes all the rows from all the input tables. The MergeSort Action has basically the same functionality as the Append Action except that it interleaves the rows of the input tables to produce a SORTED table as output. The sort-order specified inside the MergeSort Action must match the sort-order of the input tables (…and all input tables must be sorted in the same way). At run-time, the MergeSort Action analyzes the meta-data of all the input tables to check if they are properly sorted (…and abort if that’s not the case).
The algorithm used to produce the output table is the “Merge Sort” algorithm that has been described in section 188.8.131.52. (about the Sort Action).