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Document stores allow complex data structures, called documents, to be used as values and accessed in more ways than simple key lookup. When designing a data model for document databases, documents should be designed to group data that is read together.

Consider an online game that requires a database to store information about players’ game state. The player state includes

 Player name

 Health score

 List of possessions

 List of past session start and end times

 Player ID

The player name, health score, and list of possessions are often read together and displayed for players. The list of sessions is used only by analysts reviewing how players use the game. Since there are two different use cases for reading the data, there should be two different documents. In this case, the first three attributes should be in one document along with the player ID, and the sessions should be in another document with player ID.

When you need a managed document database in GCP, use Cloud Datastore. Alternatively, if you wish to run your own document database, MongoDB, CouchDB, and OrientDB are options.