Thread: Materialized Views
Hi, I've been reading an interesting article which compared different database systems, focusing on materialized views. I was wondering how the postgresql developers feel about this feature ... is it planned to implement materialized views any time soon? They would greatly improve both performance and readability (and thus maintainability) of my code. In particular I'm interested in a view which materializes whenever queried, and is invalidated as soon as underlying data is changed. Mike
On Mon, 16 Jan 2006 15:36:53 +0100 Michael Riess <mlriess@gmx.de> wrote: > Hi, > > I've been reading an interesting article which compared different > database systems, focusing on materialized views. I was wondering how > the postgresql developers feel about this feature ... is it planned > to implement materialized views any time soon? They would greatly > improve both performance and readability (and thus maintainability) > of my code. > > In particular I'm interested in a view which materializes whenever > queried, and is invalidated as soon as underlying data is changed. You can already build materialized views in PostgreSQL, but you end up doing the "heavy lifting" yourself with triggers. You put insert/update/delete triggers on the underlying tables of your view that "do the right thing" in your materialized view table. I wrote a blog entry about this recently, http://revsys.com/blog/archive/9, where I used a very simple materialized view to achieve the performance I needed. It has links to the relevant documentation you'll need however to build triggers for a more complex situation. Hope this helps! --------------------------------- Frank Wiles <frank@wiles.org> http://www.wiles.org ---------------------------------
hi mike > In particular I'm interested in a view which materializes whenever > queried, and is invalidated as soon as underlying data is changed. from the german pgsql list earlier last week: http://jonathangardner.net/PostgreSQL/materialized_views/matviews.html this seems to be pretty much what you want (except you'll have to update everything yourself). would be really nice if pgsql supports this "in-house" cheers, thomas
Thanks! Of course I know that I can build materialized views with triggers, but so far I've avoided using triggers altogether ... I would really appreciate something like "create view foo (select * from b) materialize on query". But I'll look into your blog entry, thanks again! Mike > On Mon, 16 Jan 2006 15:36:53 +0100 > Michael Riess <mlriess@gmx.de> wrote: > >> Hi, >> >> I've been reading an interesting article which compared different >> database systems, focusing on materialized views. I was wondering how >> the postgresql developers feel about this feature ... is it planned >> to implement materialized views any time soon? They would greatly >> improve both performance and readability (and thus maintainability) >> of my code. >> >> In particular I'm interested in a view which materializes whenever >> queried, and is invalidated as soon as underlying data is changed. > > You can already build materialized views in PostgreSQL, but you > end up doing the "heavy lifting" yourself with triggers. You put > insert/update/delete triggers on the underlying tables of your > view that "do the right thing" in your materialized view table. > > I wrote a blog entry about this recently, > http://revsys.com/blog/archive/9, where I used a very simple > materialized view to achieve the performance I needed. It has links > to the relevant documentation you'll need however to build triggers > for a more complex situation. > > Hope this helps! > > --------------------------------- > Frank Wiles <frank@wiles.org> > http://www.wiles.org > --------------------------------- > > > ---------------------------(end of broadcast)--------------------------- > TIP 9: In versions below 8.0, the planner will ignore your desire to > choose an index scan if your joining column's datatypes do not > match >