[Qgis-developer] cache records

[Jürgen E. Fischer]

Hi Giovanni,

On Mon, 16. Jan 2012 at 13:29:23 +0000, Giovanni Manghi wrote:
> I'm testing with a 145k records table and I don't get the crash, but
> loading take indeed much longer then before (this feature was added).

It's not supposed to speed up loading - it's just to avoid reloading.

Before it would first fetch all ids from the provider and then fetch each
visible row by id.  When scrolling it would fetch the rows that became visible
and when scrolling back reload what was visible before from the provider.

The caching avoids the latter.  The n last fetched lines are cached, so the
rows don't need to be reloaded and visiting areas that you've already been to
should be quicker (eg. jumping to the end of the list and back to the
start).  Once you close the attribute table, the cache is also destroyed.


Jürgen

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