Do Blob properties on entities affect query performance?

Posted by Jaroslav Záruba on Stack Overflow See other posts from Stack Overflow or by Jaroslav Záruba
Published on 2010-05-09T06:12:42Z Indexed on 2010/05/09 6:18 UTC
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google-datastore

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java

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blob

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google-app-engine

Hello

I'm trying to make my mind on whether to store a binary representation of an entity as its Blob property, or whether I better keep the blobs in some separate 'wrapping' class.
Possible impact on memory heap and/or a query execution time are my concerns in the first case, complexity votes against the other one.

I know Blobs are not indexed, i.e. index size is not what I'm worrying about. Also I assume for blobs Datastore puts defaultFetchGroup to false, but does it mean that blobs don't make a difference in queries?

Regards
J. Záruba

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