Re: Tuning to speed select
| От | louis gonzales |
|---|---|
| Тема | Re: Tuning to speed select |
| Дата | |
| Msg-id | 44DA3E75.50509@linuxlouis.net обсуждение исходный текст |
| Ответ на | Re: Tuning to speed select ("Harald Armin Massa" <haraldarminmassa@gmail.com>) |
| Ответы |
Re: Tuning to speed select
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| Список | pgsql-general |
I'm not so sure about that, when you create a view on a table - at least with Oracle - which is a subset(the trivial or 'proper' subset is the entire table view) of the information on a table, when a select is issued against a table, Oracle at least, determines if there is a view already on a the table which potentially has a smaller amount of information to process - as long as the view contains the proper constraints that meet your 'select' criteria, the RDBMS engine will have fewer records to process - which I'd say, certainly constitutes a time benefit, in terms of 'performance gain.' Hence my reasoning behind determining IF there is a subset of the 'big table' that is frequented, I'd create a view on this, assuming postgresql does this too? Maybe somebody else can answer that for the pgsql-general's general information? query-speed itself is going to be as fast/slow as your system is configured for, however my point was to shave some time off of a 1M+ record table, but implementing views of 'frequently' visisted/hit records meeting the same specifications. Harald Armin Massa wrote: > Louis, > > Views certainly help in managing complexity. They do nothing to > improve query-speed. > > Querying a view gets rewritten to queries to the underlying tables on > the fly. > (as long as there are no materialized views, which are still on a the > TODO list) > > -- > GHUM Harald Massa > persuadere et programmare > Harald Armin Massa > Reinsburgstraße 202b > 70197 Stuttgart > 0173/9409607 > - > Let's set so double the killer delete select all.
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