Re: What to index to speed up my UNION views?
От | Jim C. Nasby |
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Тема | Re: What to index to speed up my UNION views? |
Дата | |
Msg-id | 20060327125705.GE80726@pervasive.com обсуждение исходный текст |
Ответ на | What to index to speed up my UNION views? (Ashley Moran <work@ashleymoran.me.uk>) |
Ответы |
Re: What to index to speed up my UNION views?
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Список | pgsql-general |
On Mon, Mar 27, 2006 at 11:44:00AM +0100, Ashley Moran wrote: > I had a bright idea that has not worked quite as well as I thought. > > We have a web sites for selling cars that we are trying to expand to vans, > bikes etc. We get a datafeed containing prices and technical data updated > nightly (for cars it's about 2.3GB, others are smaller). This comes into SQL > Server as one database per vehicle type, and we export it as CSV data, which > is COPY'd into Postgres. > > The current version of the application uses Hibernate. Now, as the database > for each vehicle type has an idential schema I thought it would be possible > to use views to access the underlying data so we don't have to duplicate the > mappings for each data type. So for example, there is a table "capmod" which > stores vehicle models. Unfortunately, the primary key column for the table > is not unique across all dataset databases, so a model id used to identify a > car model in the car database may also identiffy a van model in the van > database. BTW, you might also find inheritance to be of use: http://www.postgresql.org/docs/8.1/interactive/ddl-inherit.html -- Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
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