On May 14, 2007, at 11:27 AM, Graham Stratton wrote:
> I ran a few get()s with non-existent ids (which are therefore
> returning no rows, confirmed by setting engine.echo to 'debug'). The
> average query time was about 80ms, though it varied from 56ms to
> 110ms.
> I also called engine.execute with the generated SQL a few times,
> substituting in different ids. The query time was quite consistently
> around 17ms.
>
engine.execute() also compiles the query at that point. the compile
() phase of query() also has a lot more work to do, again more so
with eager loads, in order to allow the full hierarchy of mappers to
generate the final query appropriately. i would not guess that its
3-6 orders of magnitude slower, however.
if you want to truly compare compilation times, take your raw select
(), and time:
select.compile()
versus your Query, saying:
query.compile(<optional WHERE clause>).compile()
since those are the more basic operations youre comparing, you can
run the profiler on those in a straightfoward manner.
you can also use your raw select() directly with the query to return
a scalar via:
query.select(myselect).scalar()
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