[Qgis-developer] Oracle layers - improving the speed

Jonathan Moules jonathanmoules at warwickshire.gov.uk
Mon Feb 10 07:56:17 PST 2014

Hey Jürgen,

> There's always an extent, but that not necessarily reflect an actual bbox,
> but
> just sets the available bounds, which are often set much bigger than the
> actual
> data.  But the bounding box is determined after insertion of the layer
> anyway.

Fair point, but for us it's definitely still preferable over having QGIS
"hang" for several minutes waiting for Oracle to perform a MBR check on a
table with millions of features.

> To insert the layer we just need tablename, column, type and srid - and
> that's
> what the thread searches for.

How about doing the search for "type" when the layer is actually added to
QGIS? It could also confirm the other stuff (which it got from metadata) at
that time too.

> An additional idea would be to use the filters upfront.  Currently you can
> only
> filter the result of the layer search after the search has already been
> run.
> Instead we could reduce the searches we want by just looking for tables
> with
> given (partial) name, in a given schema, srid and/or geometry type.
>  Especially
> in cases where the search is expensive, because there are loads of tables,
> this
> is would even be useful if performance wasn't an issue.

> And that would also be interesting for all other database providers.

Oooh, I like that idea!

Kind regards,

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