10.1 SDE Raster Storage Size blow-out

[RobertFitzgerald]

Hi all,

We have found that there is a significant blow-out in storage size of raster datasets in ArcSDE 10.1 in comparison to the storage size currently stored for ArcSDE 9.3.   It also exceeds the estimated storage size (using ESRI formula) and in some cases more than 100%.

The emerging pattern is that a storage size blow-out occurs with raster datasets that were initially created in versions ArcSDE 9.2 and under.

We have also found raster data created in ArcSDE 10.1 not as efficient in storage as with previous ArcSDE versions.  Both Lz77 and jpeg75 compressions exceed the estimated storage size.

ESRI have offered work-arounds, but no explanation.

Has anyone had any similar issues and, if so, have you come up with a solution.

thanks,

[MarcoBoeringa]

Hi Robert,

I don't have 10.1 yet and no ArcSDE available, but looking at this 10.1 Help topic:

What's new for raster and image data in ArcGIS 10.1

I started wondering what type of raster data you are using? Is it classified and visible in ArcCatalog as the new "Raster product" data type, e.g. Landsat imagery with a Multispectral layer.

The Help is not so clear here, but there seems to be an indication of possible extra raster viewing layers being created:

"... A raster product is a raster dataset that uses metadata and header information to pre-create a raster layer from the raw data. ... Instead, they contain one or more derived raster datasets, such as a multispectral or pan-sharpened product, depending on the metadata and available bands. ..."

If these derived layers are indeed not being created "on-the-fly" but pre-created and stored like for example raster pyramids, it would definitely explain a possible serious increase in storage requirements compared to previous versions of ArcSDE raster data storage.

Lastly, when, at what version, did ArcGIS introduce the "Overview" with mosaics...? Besides pyramids, these could add to raster storage too.