Mosaic Dataset: FGDB vs. SDE (for migrating existing Image Server ISDef services)

Question

Hello -
We have existing ArcGIS Image Server (9.3) services that we are migrating to Mosaic Datasets (10.1) by converting existing ISDef files.  All original Tiff's and Overviews images exist on our server.

We were wondering if there are any advantages/disadvantages of having our converted image services stored in Mosaic Datasets in a file gdb vs. having the Mosaic Datasets stored in our enterprise (Oracle) SDE gdb?  All images (Tiff's and Overviews) will remain on the file system on our server.

Any thoughts or suggestions are appreciated - thanks!

EllenDean · Answer

Thanks so much for your responses.

Yes, caching is an option and we'll keep that in mind.  So far, we've had very good performance with our current 9.3 image services without caching even with our external web applications.

I think we were leaning toward the file gdb direction, so it's good to hear about the performance issues with SDE, even though I'm sure these will get better in time.

Thanks again -

JeffreySwain · Answer

It all depends on your comfort level with SDE permissions and your desired product.  The mosaic dataset seems will work in either medium.  If you plan on publishing the mosaic dataset the normal permission issues are necessary to see the data and if you create the overviews in the SDE, then Server will need permission to access the database.  There are also some performance issues at this point with SDE, where the file based version will be quicker.  Also pay attention on the same help document, the requirements to make the data accessible.

Per help, ArcSDE geodatabases are convenient and powerful, but often don't yield as fast of performance as you would see when accessing the data locally.

JoeFlannery · Answer

Ellen:

Is caching an option for you?

If I am correct, a Mosaic Dataset in an FGDB with TIF and Overview files would be considered "dynamic" and not the fastest image service web option.  If you use your FGDB/MoDat to build an Image Service that uses cache tiles, you will have a fast image service and, from my experience, the cache tiles consume much less space on the server than the TIF files do.