datastore
21 Nov 2008
Google today released Google App Engine SDK 1.1.6 (announcement, download) which, among other things, brings with it datastore keys that you can sort and filter on.
I've been working a lot with Google App Engine in the past few months. I still maintain, as I reiterated recently in my Boagworld interview with Paul, that it's a great idea and has great potential. And the Google App Engine team has been wonderful in working with me and helping me out. Unfortunately, there are a couple of fundamental issues that must be addressed, and addressed properly, before Google App Engine can be taken seriously as a web application platform.
(And no, Java support is most definitely not one of them.)
Backing up and restoring the datastore in your local SDK can be very useful for several use cases. Personally, I find that I alternate between running the local SDK with a restore of data from the deployment environment and with an empty or test datastore.
The local SDK slows down painfully when you populate it with real amounts of data so sometimes I test with an empty datastore while developing. Restoring data, however, takes a long time too so I don't want to run my restore process all the time. And I don't have to, since I can simply backup the local datastore and restore is by copying it back.
This is a quick screencast to show you the data export solution I've created for Google App Engine that lets you backup your application's datastore and restore it either locally on your development machine or on the same Google App Engine application on the deployment environment or on a different Google App Engine application (which you can use as a staging environment).
Google App Engine, we need to have a talk about your datastore keys.
Your keys can have names but they cannot start with a number. Keys can also have IDs, which are numeric. We can read those, but can't set them.
When I put an entity into the datastore for the first time, you assign it a numeric ID. I'd love to be able to create an entity on a different instance with the same ID you've assigned it but I can't. I'd love to be able to create an entity with the same key that you've assigned it (again, on a separate instance -- say the local SDK or a different app), but I can't set keys directly.