[sqlalchemy] Re: How to improve performance of sqlalchemy based application?

2009-01-24 Thread Brett
I drastically sped up my inserts by precomputing any defaults on a column and passing them explicitly instead of calculating them on each insert. For example, each row had a timestamp and the timestamp was being calculated on each insert for each row. Since I was inserting them all at the same

[sqlalchemy] Re: How to improve performance of sqlalchemy based application?

2009-01-24 Thread Brett
See it here on lines 323-352: http://bazaar.launchpad.net/~bauble/bauble/trunk/annotate/head%3A/bauble/plugins/imex/csv_.py --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group,

[sqlalchemy] Re: How to improve performance of sqlalchemy based application?

2009-01-18 Thread Andreas Jung
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 18.01.2009 16:32 Uhr, Victor Lin wrote: Hi, So I think that would be better to buffer data and flush them. This is easily spoken the implementation pattern of SA: unit-of-work. You might check the documentation. - -aj -BEGIN PGP

[sqlalchemy] Re: How to improve performance of sqlalchemy based application?

2009-01-18 Thread Michael Bayer
inserting bulk data is most efficient if you use an insert many: connection.execute( table.insert(), [{..row...}, {...row...}, {...row..} ..] ) For additional performance, you want to ensure that the above insert is not relying on any python-level default executions (like when

[sqlalchemy] Re: How to improve performance of sqlalchemy based application?

2009-01-18 Thread Ramiro Morales
On Sun, Jan 18, 2009 at 1:32 PM, Victor Lin borns...@gmail.com wrote: Hi, I am building some applications that insert data to database heavily. I commit in for-loop every iteration. It seems that it is not a smart way to commit data every iteration. SQL queries implies expensive IO action.

[sqlalchemy] Re: How to improve performance of sqlalchemy based application?

2009-01-18 Thread Ramiro Morales
On Sun, Jan 18, 2009 at 1:46 PM, Ramiro Morales cra...@gmail.com wrote: Take a look at ticket #6095 to know the motivation and rationale behind the addition of the through option and some of the advantages when compared with using you own model with FKs to the two related models. Also and