I agree with Moti, but I think we might have an alternative.
Does our DAO layer support named queries (aka PreparedStatements
loaded from a properties file)? Those are generally plain SQL queries
with arguments that are compiled in advance and still allow direct
access to the JDBC internals without the heavy translation layer.
On Sun, Mar 26, 2017 at 4:12 PM, Yevgeny Zaspitsky <yzaspits(a)redhat.com> wrote:
Recently I had a task of performance improvement in one of our network
related flows and had some hard time following our DAL code and one of the
outcomes of the task was defining a couple of new quite simple, but neat
When I came to coding those new queries I remembered how hard was following
the existing DAL code, I decided to make my own new methods clearer. So I
created  and  patches.
Everything is quite standard there beside the fact that they do not use any
stored procedure, but use SQL directly, IMHO by that they save time that I
spent in trying to follow what a DAO method does. Looking into the method
code you get the understanding of what this method is all about:
no looking for a stored procedure name that is buried in the DAO class
no looking for the SP definition
So I'd like to propose moving towards this approach in general in all cases
when nothing beyond a simple SQL is needed (no stored procedure programming
language is needed).
From my experience with the performance improvement task it looks like
people avoid adding new queries for a specific need of a flow, instead they
use the existing general ones (e.g. dao.getAllForX()) and do the actual join
in the bll code.
IMHO the proposed approach would simplify adding new specific queries and by
that would prevent a decent part of performance issues in the future.
I do not propose changing all existing SP's to inline queries in a once, but
to allow adding new queries this way. Also we might consider converting
relatively simple SP's to inline SQL statements later in a graduate way.
 - https://gerrit.ovirt.org/#/c/74456
 - https://gerrit.ovirt.org/#/c/74458
Devel mailing list