Re: Optimizer : query rewrite and execution plan ?
| От | Roberts, Jon |
|---|---|
| Тема | Re: Optimizer : query rewrite and execution plan ? |
| Дата | |
| Msg-id | 1A6E6D554222284AB25ABE3229A92762715551@nrtexcus702.int.asurion.com обсуждение исходный текст |
| Ответ на | Re: Optimizer : query rewrite and execution plan ? (Erik Jones <erik@myemma.com>) |
| Список | pgsql-performance |
> > > >>> Since the SQL is not your fault and difficult to control, it is an > >>> argument in favour of an optional planner mode that would perform > >>> additional checks for redundant clauses of various kinds. The > > default > >>> for that would be "off" since most people don't suffer from this > >>> problem. BO isn't the only SQL generating-client out there, so I > > think > >>> this is a fairly wide problem. > >> > >> I would have to disagree. I spend a lot of time writing code that > >> generates SQL from a business app and feel strongly that any > >> optimisation is my responsibility. > >> > > > > The point to a BI tool like BO is to abstract the data collection > > and do > > it dynamically. The SQL is built at run time because the tool is > > designed to give the end user as much flexibility as the data > > structure > > allows to query the data however they want. > > > > It isn't feasible, possible, or recommended to rewrite all of the > > possible generated SQL that could be designed at runtime by the tool. > > No, but it is feasible to expect the tool to generate well-formed > queries without redundant clauses. There are plenty that do. > Agreed. Jon
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