[Qgis-user] Re: Re: [Qgis-developer] PostGIS manager v0.5

[Martin Dobias]

On Thu, Jul 9, 2009 at 8:59 AM, Düster Horst<Horst.Duester at bd.so.ch> wrote:
> Martin
> I found out further issues related with OID Indexes (1) and table versioning
> (2) and one enhancement (3).
> 1.
> When I select a table with OID index, the meta data Indexes part shows:
> Name Column(s)
> afu_prog05_oid_idx ??? (#-2)
> afu_prog05_idx wkb_geometry

Ah, tables with oids, that's something I've completely forgotten...
Anyway, isn't it discouraged to use oids for regular tables?

> 2.
> * The schema select box content should be sortet.
> * The geometry index and all other indexes of the versionized table should
> be a patial index with the constaint "where time_end = NULL ". With a
> partial index you will have huge performance advantages. With the time the
> amount of archived or historized records will grow up. P.e. one table of our
> cadastral data contains more than 1 Mio records, but 700000 of them are not
> in production state (end_time <> NULL). With the partial index these records
> don't exists for Postgres, as the result you do not have any performance
> problems with your production data.

That's why I'm not adding any indexes to the tables with versioning,
because I wasn't sure how to do it correctly. I was thinking about
using multicolumn indexes - e.g. geometry+endtime, that would probably
do the right thing too. But the partial indexes seem to be more
appropriate. Thanks for sharing.

> 3. I would be nice to add a selected table to Qgis mapcanvas.

Already on my TODO :-)

Bye
Martin