[Zope] zcatalog query sends zope spinning

I have a ZCatalog containing some 400,000+ objects. I recently rebuilt the catalog due to corruption, so it should be in pristine condition. Today I issued a simple query (one condition) of the ZCatalog which should have returned a very large number of objects. My intention was to generate a data export that I could then import into another system. The query ran for 2 hours, at which point I discovered that Zope was hung and completely unresponsive. I had to break out the 'kill -9' to get it to die. Does anyone have any hints on getting large amounts of data out of the ZODB using the ZCatalog (or otherwise)? My efforts thus far have proven futile. ID:[{20040902144153.711.468943402-12.6.18.86}]