Google Datastore low-level api query by key property

Posted by Keyur on Stack Overflow See other posts from Stack Overflow or by Keyur
Published on 2010-05-26T23:27:05Z Indexed on 2010/05/26 23:31 UTC
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google-app-engine

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google-datastore

I'm using the low-level google datastore api and I want to query by the key property and another property (let's call it category).

I need to query based on a list of keys for which I'll use the IN operator. I know that the max. number of values you can provide for the IN clause is 30.

I have 2 questions:

Does the limit of 30 IN values apply to the key property as well?
Do I need to create a composite index on {_key_ + category} or just on {category} for this query?

Thanks, Keyur

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