[fdo-users] Improving performance for NEN1878 provider, howto?

[Robert Fortin]

Badreddine,

Isn't it the combination of count and spatialExtents that need to be
optimized?
I believe Map looks for the equivalent of 

Select SpatialExtents(geometry), count(*)  from <class>

RF


-----Original Message-----
From: fdo-users-bounces at lists.osgeo.org
[mailto:fdo-users-bounces at lists.osgeo.org] On Behalf Of Badreddine
Karoui
Sent: Monday, October 01, 2007 9:42 AM
To: fdo-users at lists.osgeo.org
Subject: RE: [fdo-users] Improving performance for NEN1878 provider,
howto?

Hi,

  You may want to implement the FdoISelectAggregates command plus the
SpatialExtents and Count functions. If these two functions are not
implemented, then Map will scan all the geometries to find the minimum
bounding rectangle of all the data. 

Badreddine

-----Original Message-----
From: fdo-users-bounces at lists.osgeo.org
[mailto:fdo-users-bounces at lists.osgeo.org] On Behalf Of Piet Bibber
Sent: Monday, October 01, 2007 7:46 AM
To: fdo-users at lists.osgeo.org
Subject: [fdo-users] Improving performance for NEN1878 provider, howto?


Hello,

My NEN1878 provider is almost done, but performance is not so fantastic
when
reading the geometry; reading the schema is alright.
That is stange, as I cache in the geometry when I read the schema
(NEN1878
schema discovery requires a full file scan; no seperate schema header).
(The
schema is read within 3 seconds for a 2.3MB file, including the geometry
and
attributes (all in memory (using STL)).
The SDF and SHP all seem so fast :-)

Map 3D seem to spend most of his time caching in the geometry (see
source
code below)

I based my provider on the SHP provider, the reader seem to use
FDO_READER
template, but I can't find where that points to. Maybe there are better
optimized readers.

Thanks.
Piet

Excerpt from the source files:

    FdoByteArray * CreateCachedGeometry(FdoByteArray* fgfByteArray_I)
    {
        FdoByteArray*   fgfByteArray = fgfByteArray_I; // it may be
reallocated
        int             count = mFeature->GetNumPoints();
        FdoInt32        numPointOrds = 2;
        FdoInt32        numBytesForOrdinates = numPointOrds *
sizeof(double)
* count;
        FdoInt32        numParts = 0;
        FdoGeometryType fdoGeomType  = GetFdoGeometryType();
        FdoInt32        dimensionality = FdoDimensionality_XY;
        FdoInt32        numPositions   = mFeature->GetNumPoints();

        fgfByteArray->Clear();

        fgfByteArray = FdoByteArray::Append(fgfByteArray,
sizeof(fdoGeomType), (FdoByte *) &fdoGeomType);
        
        switch (fdoGeomType)
        {
        case FdoGeometryType_None:
            break;

	    case FdoGeometryType_Point:
            fgfByteArray = FdoByteArray::Append(fgfByteArray,
sizeof(dimensionality), (FdoByte*)&dimensionality);
            fgfByteArray = FdoByteArray::Append(fgfByteArray,
numBytesForOrdinates,   (FdoByte*)mFeature->GetPoints());
		    break;

	    case FdoGeometryType_LineString:
            fgfByteArray = FdoByteArray::Append(fgfByteArray,
sizeof(dimensionality), (FdoByte *) &dimensionality);
            fgfByteArray = FdoByteArray::Append(fgfByteArray,
sizeof(count),
(FdoByte *)&count);
            fgfByteArray = FdoByteArray::Append(fgfByteArray,
numBytesForOrdinates, (FdoByte *)mFeature->GetPoints());
		    break;

	    default:
            throw
FdoException::Create(FdoException::NLSGetMessage(FDO_NLSID(FDO_10_UNSUPP
ORTEDGEOMETRYTYPE)));
        }

	    return (fgfByteArray);
    }


// Returns pointer to vector of DoublePoints
inline DoublePoint* Nen1878Feature::GetPoints()
{
    return (&mCoordinates[0]);
}

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