> SQLAlchemy batches inserts in the ORM as is possible and with Core you
> do this explicitly, both make use of cursor.executemany() which is then
> determined by how the DBAPI handles it.
Ummm. If that is true, why this line is used when I pass a list of values (its
from visit_insert)? Clearly sqlalchemy creates big string `VALUES (%s, %s),
(%s, %s)....` by itself without executemany.
elif insert_stmt._has_multi_parameters: text += " VALUES %s"
% ( ", ".join( "(%s)" % (
', '.join(c[1] for c in crud_param_set) )
for crud_param_set in crud_params ) )
I've written benchmark again.
https://gist.github.com/purpleP/35c4920020ad95585419eb1d250200b7
TLDR; alchemy is more than three times slower than executemany for inserting
10000 values.
for a million values sqlalchemy drops with OperationalError.
Here's a vmprof visualization for 10000 values
http://vmprof.com/#/c7f9a4fd-55f9-469d-b6e4-b7cac04473fa .
vmprof is much better than cProfile give it a try if you still coding in python.
If you will need more data then just a visualization - I'll try to provide it.
But you have the benchmark code in the gist.
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SQLAlchemy -
The Python SQL Toolkit and Object Relational Mapper
http://www.sqlalchemy.org/
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