Le samedi 17 janvier 2015 22:10:23, Paul Ramsey a écrit :
> How accurate is the fast feature count supposed to be? An estimate
> could be pulled from the system stats pretty much instantly, but it
> wouldn't be exact.
From the documentation :
/**
\fn int OGRLayer::GetFeatureCount( int bForce =
How accurate is the fast feature count supposed to be? An estimate
could be pulled from the system stats pretty much instantly, but it
wouldn't be exact.
I come to this question via the FDW work, where the first step PgSQL
does is to try and plan the query and get selectivity estimates from
all t
Selon Paul Ramsey :
> The PgSQL driver is returning TRUE for OLCFastFeatureCount and then running
> "SELECT Count(*)â to fulfill the request. Since that is actually going to
> apply a full table scan, itâs not *really* a fast feature count in my
> estimation, but perhaps GDAL has a different
The PgSQL driver is returning TRUE for OLCFastFeatureCount and then running
"SELECT Count(*)” to fulfill the request. Since that is actually going to apply
a full table scan, it’s not *really* a fast feature count in my estimation, but
perhaps GDAL has a different standard? What’s the standard f
