Bulk insert with SQLAlchemy ORM

Question

Is there any way to get SQLAlchemy to do a bulk insert rather than inserting each individual object. i.e.,

doing:

INSERT INTO `foo` (`bar`) VALUES (1         


        

Answer 1

All Roads Lead to Rome, but some of them crosses mountains, requires ferries but if you want to get there quickly just take the motorway.

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In this case the motorway is to use the execute_batch() feature of psycopg2. The documentation says it the best:

The current implementation of executemany() is (using an extremely charitable understatement) not particularly performing. These functions can be used to speed up the repeated execution of a statement against a set of parameters. By reducing the number of server roundtrips the performance can be orders of magnitude better than using executemany().

In my own test execute_batch() is approximately twice as fast as executemany(), and gives the option to configure the page_size for further tweaking (if you want to squeeze the last 2-3% of performance out of the driver).

The same feature can easily be enabled if you are using SQLAlchemy by setting use_batch_mode=True as a parameter when you instantiate the engine with create_engine()