[postgis-devel] Concurrent Modification and Feature Locking

[Cory Horner]

Hi Sandro et al,

We're currently working on eliminating some bugs in the geotools postgis 
plugin, for use in uDig, etc.  One problem we've encountered has been 
concurrent modification of features.  In geotools we keep a transaction 
alive for some time, as the user tweaks features to their heart's 
content.  Unfortunately, when one user modifies a feature and keeps the 
transaction open, a second user attempting to edit the same feature will 
experience a lockup while they wait for the first user to either commit 
or revert.

What i'm wondering is if there is a way to ask PostGIS (postgres) if a 
feature is locked, or is lockable, so we may toss exceptions or 
otherwise deny modification of a feature when it is not possible?

Thanks,
Cory.