Changes between Initial Version and Version 1 of rfc13_createfeatures

Timestamp:

May 14, 2007, 8:11:53 AM (17 years ago)

Author:

Kosta

Comment:

--

rfc13_createfeatures

@@ +1 @@
+'''RFC 12: Improved File Management'''
+
+    Author: Konstantin Baumann[[BR]]
+    Contact: baumann@hpi.uni-potsdam.de[[BR]]
+    Status: Proposed 
+
+'''Summary'''
+
+Some OGR drivers can dramatically increase the speed of and optimize the insertion of a set of features, if the driver knows, that there is a whole set of features that should/could be inserted at once (instead of just one by one).
+
+'''!CreateFeatures()'''
+
+The following new virtual method is added to the OGRLayer class, with an analogous C function:
+{{{
+virtual OGRErr CreateFeatures( OGRFeature** papoFeatures, int iFeatureCount );
+}}}
+
+A default implementation is given as below:
+{{{
+OGRErr OGRLayer::CreateFeatures(
+    OGRFeature **papoFeatures,
+    int iFeatureCount
+) {
+    for(int i = 0; i < iFeatureCount; ++i) {
+        OGRErr error = CreateFeature( papoFeatures[i] );
+        if( error != OGRERR_NONE ) return error;
+    }
+    return OGRERR_NONE;
+}
+}}}
+
+This triggers the old behavior of an unoptimized insertion.
+
+Individual drivers can override the default implementation and can implement an optimized algorithm for inserting a set of features.
+
+'''Additional Notes'''
+
+Based in this new interface function, I was able to increase the insertion speed of features in the MySQL driver from 40 per second to up to 800-2000 per second. I think other drivers can benefit from this change, too.
+
+'''Implementation Plan'''
+
+A patch for the describe additions can be trivially provided.
+
+I can provide another patch based on this interface which contains the optimized implementation for the MySQL driver.