King.Oracle layer previews can render feature source indefinitely busy and crash the mapagent handler
|Reported by:||jng||Owned by:|
|Cc:||zspitzer, trevorwekel||External ID:|
We've discovered a serious defect with the King.Oracle provider with regards to the SpatialExtents() aggregate function.
Instead of returning one result (the computed MBR) of a given feature class, it instead returns the same computed MBR for each result in the feature class!
This problem can easily manifest itself when previewing a King.Oracle based Layer Definition in Maestro or MapGuide Studio as this aggregate function is used to get a preview-ready MBR.
For a moderately large Oracle table, this will crash the mapagent handler and send the King.Oracle feature source into a semi-permanent locked state in the feature source cache (ie. Attempts to overwrite the feature source will throw "resource is busy" errors).
When you do the layer preview, the access.log file is flooded with GetDataRows() calls, which is the provider returning the same MBR for each row in the oracle table.
A proposed solution has already been given to Haris to fix this defect in the provider. This ticket is simply to indicate the release-blocking severity of this defect.