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Mike Bayer
40f8aadd58
- added READMEs to all examples in each __init__.py and added to sphinx documentation - added versioning example - removed vertical/vertical.py, the dictlikes are more straightforward
21 lines
1.0 KiB
Python
21 lines
1.0 KiB
Python
"""a basic example of using the SQLAlchemy Sharding API.
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Sharding refers to horizontally scaling data across multiple
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databases.
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The basic components of a "sharded" mapping are:
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* multiple databases, each assigned a 'shard id'
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* a function which can return a single shard id, given an instance
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to be saved; this is called "shard_chooser"
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* a function which can return a list of shard ids which apply to a particular
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instance identifier; this is called "id_chooser". If it returns all shard ids,
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all shards will be searched.
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* a function which can return a list of shard ids to try, given a particular
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Query ("query_chooser"). If it returns all shard ids, all shards will be
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queried and the results joined together.
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In this example, four sqlite databases will store information about
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weather data on a database-per-continent basis. We provide example shard_chooser, id_chooser and query_chooser functions. The query_chooser illustrates inspection of the SQL expression element in order to attempt to determine a single shard being requested.
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"""
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