Fix luigi.contrib.sqla performance bug; don't reflect all tables #2104
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@kdbhiggins, thanks for your PR! By analyzing the history of the files in this pull request, we identified @Tarrasch, @aliavni and @soxofaan to be potential reviewers. |
kdbhiggins
changed the title
dlstadther
approved these changes
Apr 28, 2017
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Description
The sqla module can be extremely slow loading if your db has a lot of tables. This is due to unnecessary reflection of all the tables.
There was a similar bug in pandas: pandas-dev/pandas#8147
Motivation and Context
Reflection is very slow when you have lots of tables. In my case the sqla module would sit for > 30 seconds when running the line
We don't need to reflect all the tables here. Instead we can only reflect and bind the table we are interested in
Have you tested this? If so, how?
Reflection is tested in sqla_test.py and with these changes my performance issue is fixed