v0.15.0

New features:

• Pooling has been implemented, allowing for multiple concurrent databases and all the benefits that comes with it.
  • Enabled by default for databases that support it (mysql and postgres) with a minimum pool size of 1, and a maximum of 5
  • Not supported by sqlite
  • Can be changed by passing the minsize and maxsize connection parameters
• Many small performance tweaks:
  • Overhead of query generation has been reduced by about 6%
  • Bulk inserts are ensured to be wrapped in a transaction for >50% speedup
  • PostgreSQL prepared queries now use a LRU cache for significant >2x speedup on inserts/updates/deletes
• DateField & DatetimeField deserializes faster on PostgreSQL & MySQL.
• Optimized .values() to do less copying, resulting in a slight speedup.
• One can now pass kwargs and Q() objects as parameters to Q() objects simultaneously.

Bugfixes:

• indexes will correctly map the foreign key if referenced by name.
• Setting DB generated PK in constructor/create generates exception instead of silently being ignored.

Deprecations:

• start_transaction is deprecated, please use @atomic() or async with in_transaction(): instead.

• This release brings with it, deprecation of Python 3.6 / PyPy-3.6:

  This is due to small differences with how the backported aiocontextvars behaves
  in comparison to the built-in in Python 3.7+.

  There is a known context confusion, specifically regarding nested transactions.