The amount of time that the Mosaic (Data Management) tool takes to load a raster into an existing raster dataset in a file geodatabase grows over many iterations.
Last Published: February 24, 2016ArcGIS for Desktop
Bug ID Number
July 29, 2015
January 9, 2021
ArcGIS for Desktop
After review by the development team, it has been determined that this issue is related to a known limitation with the software that lies outside of Esri's control. The issue's Additional Information section may contain further explanation.
Each time a geoprocessing tool is executed, a record of its execution is written to the log history. If the log history becomes very large, it can signfigantly affect the execution time of subsequent tools. The solution is to disable the logging with the python command