Re: Does it make sense to break a large query into separate functions?

On 08/05/13 23:40, Seref Arikan wrote:
> Greetings,
>
> I have a domain specific language implementation that ends up as sql
> after an automatic transformation/code generation phase.
> The complexity of the generated sql queries can be significant, with
> lots of self joins and many other criteria injected into sql.
>
> I've just noticed that some parts of the autogenerated queries can be
> functions on their own. Would moving these parts to their own functions
> help the query planner?
>
> There are any two tables and all queries use them, so I thought the
> query planner may be able to do better if I let it deal with smaller
> queries rather than one quite large one. I don't know how the query
> planner works when there are calls to other functions from a function
> though.
>
> Changing the code generator would take time, so I decided to ask for
> more educated input than mine.
>
> Best regards
> Seref
>
Hi Seref,
The code generated sql queries isn't giving you much to work with (or a
choice). However I suspect its doing its best dealing with this data
structure (relationship model). I could be wrong.

But that might be where the problem is.

Regards,
Julian.