The Encoded Vector Index, Parallel icon indicates that multiple tasks were used to perform the encoded vector index selection in parallel. This allows for faster scans that can be more easily processed in parallel. The elements of the array can be 1, 2, or 4 bytes in length, depending on the number of distinct values that must be represented. Because of their compact size and relative simplicity, encoded vector indexes provide for faster scans and can be more easily processed in parallel.