OGR JOIN performance problem on Linux

[Dirk Jesko]

Hello,

I have two machines running Apache 2 with MapServer 4.2.* (all necessary
libraries are the current stable versions). One map server is running on
Windows XP the other on Linux. Both systems contain the same data and
mapfiles (besides the paths of course). One of the layers is an OGR
connection to two shape files which are joined. One file contains
approx. 200 rows with information the other approx. 30000 points with
references to the information. The points are displayed. Both shapes
have indexes associated (created separately on the according machine).
While the join-query is very fast on Windows (it takes only a few
seconds to display all points if the index is present), it takes ages on
Linux (it makes no difference whether there is an index or not).
Sometimes the web server even returns an error since the query takes to
long. My guess would be that map server (resp. OGR) does not use the
index on Linux.

I would like to know whether someone observed a similar behavior and
whether there is a possibility to speed up the query on Linux.

Thanks in advance,

Dirk Jesko

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