I'm facing some interesting speed issues with my database that only
seem to crop up within sqlalchemy. I have 2 tables in a one-to-one
relationship, with about ~1 million rows each. From Python, I grab an
object from one table (table A):
rowA = session.query(A).limit(1).one()
And then access a row in table B:
blah = rowA.b.someRow
I noticed that for ~500 of these, it started taking a long time - so I
wrapped it in time() calls:
time1 = time.time()
blah = rowA.b.someRow
print time.time() - time1
What I find is that when I run this in Python, it takes ~0.01 seconds
per object, but when I execute it directly in the database:
EXPLAIN ANALYZE SELECT *
FROM a
WHERE a.b_pk = 20;
It only takes ~0.01 milliseconds! Is there some optimization I can do
from within the Model Class definitions, or do I really need to
execute raw sql from my code to get raw speed?
Thanks,
Adrian
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