The presence of the Essence of an image in the database is due to Curator having used that previously as a proxy for an image. In large systems with a lot of images, this can make the database too large for a healthy, responsive system. Removing Essence in cases such as these allows you to free space, improving your system's performance.

This article describes how to set the values of the Essence to NULL so that only a minimal space is taken up, explains when this can be performed, and details which settings may need adjustment afterward.

Prerequisites - minimum required versions of Curator and applications

Curator version 3.4, or at minimum Curator Server 4.0.1.151, Clip Link 3.2.1.67, and Curator For Adobe 3.2.1.1 (Mac 3.2.2). 

Please note that older applications require the use of Essence. All versions of Clip Select require the use of Essence in order to display an image when loaded to the asset view, therefore the latest Clip Link might better fulfil your needs for Clip Select use, as IPV has added most of Clip Select's capabilities to Clip Link. Please check or ask for a demonstration if in doubt.

Procedure

1. Back up the Curator database (usually curatordb).
   
   
2. Stop Curator Server.
   
   
3. Ensure Curator has been updated to version 3.4 (or at a minimum Curator Server 4.0.1.151, Clip Link 3.2.1.67, and Curator For Adobe 3.2.1.1 (Mac 3.2.2)) if you have not yet done so.
   Complete the upgrade to the minimum version of Curator Server stated in the Prerequisites section above. Refer to the Curator Server steps in Upgrading Curator 3.2 to Curator 3.4 for more information on this.
   
   
4. Start Curator Server (this completes any actions involved in the upgrade). 
   
   
5. Run an ingest of images using Curator Connect and note the assets (the ingest will have created proxies of any images independent of Essence).
   
   
6. Stop Curator Server.
   
   
7. Open the script DeleteImageEssence.sql (found in Curator Arrival 3.4\Additional items for Partners) in Workbench or a similar tool, and then complete the following steps:
   1. Select your curatordb database. 
   2. Check the size of the images table. 
   3. Run the script. The output will be something like:

      curatordb.images   optimize  note         Table does not support optimize, doing recreate + analyze instead
      curatordb.images   optimize  status       OK

   4. Check the size of the images table again following this.
      
      
8. Run checks opening the recently ingested content (see step 5 above) in Clip Link/Curator for Adobe for preview (double click the image’s thumbnail).
   
   
9. For system use, once you have confirmed that this has worked successfully:
   
   
   1. You may want to stop the creation of image Essence files in the database by setting the MediaStore PROXY-IMAGE key StoreEssenceBlob value to False.
      
      
   2. To recreate any images that did not have the image proxy placed on the disc during ingest in earlier versions of Curator, SCAVENGE-IMAGE-PROXY should be set up to fit the required system metadata.