| Label | Explanation | Data Type | 
Mosaic Dataset
  | The mosaic dataset that has the items that you want to merge.  | Mosaic Layer | 
Query Definition
 (Optional)  | An SQL expression to select specific rasters to merge in the mosaic dataset.  | SQL Expression | 
Block Field (Optional)  | The field in the attribute table that you want to use to group images. Only date, numeric, and string fields can be specified as Block fields.  | Field | 
Maximum Allowed Rows Per Merged Item (Optional)  | Limits the number of items to merge. If the maximum is exceeded, the tool will create multiple merged items. The default is 1,000 rows.  | Long | 
Derived Output
| Label | Explanation | Data Type | 
| Updated Mosaic Dataset | The updated mosaic dataset.  | Mosaic Layer |