Hi Bob,

There is no doubt that TAB is a better format than SHP, but SHP isn't that
bad. Based on your description below, it seems like you are not using the
spatial index files (SBN+SBX) of the SHP format. If you use them, arcview
can actually redraw at a pretty decent speed without reading the whole SHX
or SHP file.

SBN+SBX files are closed format as opposed to the SHP+SHX files.

Kind regards

Uffe Kousgaard
www.routeware.dk


From: <[EMAIL PROTECTED]>


> With the native SHP,SHX file format the data is NOT rearranged so that
> objects adjacent on the ground are adjacent in the file. Every single
> MBR in the SHX file has to be compared with the Screen MBR. If it is on
> the screen then the full object contained in the SHP file will again be
> stored randomly ( stored in order added ) and disk access will be
> relatively slow compared to MapInfo as the heads will be jumping around
> rather than reading contiguously. So the whole SHX file needs to be
> read, if there are 4 million objects every MBR has to be read, and then
> the 200 on the screen will need to be read in full randomly ( rather
> than contiguously ) from the SHP file.


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