Edited: Oct 27, 2018
You can delete Database Collections to get more order and thin out tables that are no longer used
We second this! This feature should have been integrated months ago. Hopefully this will be available very, very soon!
You can finally remove unneeded database collections from your site! No more "NewCollectionName", "Test" or other typos polluting your database folder.
Be aware that removing your collection might have some consequences for your site, so it's better to remove Dynamic Pages, Datasets, and Reference type fields that are pointing to collection about to be deleted.
More details here: https://support.wix.com/en/article/removing-a-collection-from-your-database. Happy cleaning!
Thanks, finally arrived !!!