I tried to merge 2 big shapefiles, 220 Mb each. This causes an "out of memory" crash during the write step, after about 70 to 90 percent. I tried on 2 pc, with and without debug, machines have 8 and 16 Gbytes. Qgis/MMQgis requires about 30 mn and generates a 490 mb (all sizes include dbf, shp...)
Can you attach or send me the files in question so we can reproduce?
On the roads, they will arrive in ten minutes.
I've got the files and merged them using the 'Merge Shapefiles'-tool:
In 30 seconds I get a merged file. And when I try the in-memory option the merging was successful as well.
The only difference in MW5 is that I use a newer version of GDAL and some small general enhancements have been made to the MapWinGIS code.
And I'm using the 64-Bit version of MW5.
In a week or 2 I will create the first stable version (still waiting on the SpatiaLite v4 fix from gisinternals.com).
That's also the tool I used. I noticed also that merging was very quick the bad thing being the crash during writing. I wait until next version, hoping it soon !