auto generate indexes in datastore-indexs.xml using google app engine

Question

I am stuck with a problem while developing an application using Google app engine. In one application screen I am using filtering and a sorting technique. In the development environment(in the local system) the screen is working perfectly but when we keep my project in the production environment (in the Google app engine cloud) I am getting an exception by accessing the same screen.

I have searched the net to find the solution, I got the solution but that is very lengthy process. Here, my error is:

 <datastore-index kind="Exception" ancestor="false" source="manual">
            <property name="packageName" direction="asc"/>
            <property name="model" direction="asc"/>
            <property name="exceptionDateTime" direction="desc"/>
     </datastore-index>

For this error to resolve I have created a datastore-indexes.xml file in the web-inf folder and the error is solved in the production environment, but like the error I have lot of indexes to write in the datastore-indexes.xml. Can anyone give me the clarification and limitations to writing all the indexes or any other process to create all the indexes automatically.

Answer 1

The best case scenario is to use both the "final" datastore-indexes and datastore-indexes-auto.xml in production using Automatic index configuration. (I don't know if it works using a standard maven built war using src/main/webapp though).

I don't think it's that much of a victory, since using a generated file for production is usually a source of confusion.

Anyway you will still have to first run your queries on the dev server to get indexes generated. The production server does not generate indexes on the fly, and there is no way to programmatically create indexes.

The whole point is to make sure that your indexes are tailor made for your queries.