topic Re: Create a tile cache from mosaic dataset without overviews? in ArcGIS Enterprise Questions

Create a tile cache from mosaic dataset without overviews?

DanDowning — Mon, 15 Sep 2014 20:02:49 GMT

Arcgis Server / Linux

Should this work?

With a small subset of images I created a mosaic (with overviews) and created an image service. I then created the tile cache and everything worked fine. I'm trying to do the same thing with all the images, but I don't want to create the overviews. Should I be able to create the cache this way? Tiles are generated, but they are just white.

I found this technical article: 39255 - Caching process creates blank/white tiles when using Mosaic dataset but it didn't help me.

Thanks.

Re: Create a tile cache from mosaic dataset without overviews?

JakeSkinner — Mon, 15 Sep 2014 20:23:53 GMT

Hi Dan,

The raw imagery will only be visible to a certain scale. If there is no data at the scale, the cache tile will be blank/white. Take a look at the link that provides a formula you can use to calculate what the max scale will be:

http://resources.arcgis.com/en/help/main/10.2/index.html#//009t00000042000000

For example, if the MaxPS was 120, the max scale the data would be visible at would be:

120 * 96 / 0.0254 = 453,543

Any reason you don't want to create the overviews?

Re: Create a tile cache from mosaic dataset without overviews?

DanDowning — Mon, 15 Sep 2014 23:52:50 GMT

Hi Jake,

Thanks for the quick reply. I'm trying to avoid the overviews just to cut out any overhead that I can. There are about 300 Gb of images which is going to give us about 1 Tb of cache. I figured I'd try to save time/storage wherever I can.

The MaxPS is 9.75 so I get a max scale for the raw imagery of 36,850. I started with just caching a few levels (for testing) and I definitely didn't get to that scale so I guess that explains the white tiles.

So I assume the answer is to create overviews, right?

Thanks again

Re: Create a tile cache from mosaic dataset without overviews?

larryzhang — Tue, 16 Sep 2014 04:24:02 GMT

Dan,

Yes, MD with overviews should be used to generate caches.

By the way, worth to share two points:

1. (on your reply: generating 1TB caches from only 300 GB), the figure estimation from GP tools for the size of 'to-be-generated' caches is not right. If that is true, better to check the schema you are using..

2. please genetate caches in desktop (not in server-side). In other words, GP tools for caches can be found under 'data management tools'. In this way, you can avoid network tranffic and improve the performance for caching...