Thread: Testing Views
Hello All,
I have a problem for which a view seems like a nice solution. Basically we want to see all records in some table that are older than 5 days and haven't yet gone through further processing.
This particular view is probably simple enough that it doesn't require unit tests but I wonder how people test complex views that depend on the current date or time. I found a thread on the hackers list [1] that talked about stubbing pg_catalog.now() but was wondering if any TDD minded developers had invented anything better since then.
One option I thought of was to just not use views that depend on the current date or time and instead create a set returning function that takes the time as a parameter. Would such a function have similar performance characteristics to an equivalent view?
Cheers,
Andy
On 20/05/15 19:47, Andy Chambers wrote: > Hello All, > > I have a problem for which a view seems like a nice solution. > Basically we want to see all records in some table that are older than > 5 days and haven't yet gone through further processing. > > This particular view is probably simple enough that it doesn't require > unit tests but I wonder how people test complex views that depend on > the current date or time. I found a thread on the hackers list [1] > that talked about stubbing pg_catalog.now() but was wondering if any > TDD minded developers had invented anything better since then. > > One option I thought of was to just not use views that depend on the > current date or time and instead create a set returning function that > takes the time as a parameter. Would such a function have similar > performance characteristics to an equivalent view? > > Cheers, > Andy > > [1]: > http://postgresql.nabble.com/overriding-current-timestamp-td5507701.html How about using a 'Time Machine'? Run the database in a VM and change the date/time. You can take a clone of the VM, and recreate it multiple times from a known state. A technique we used to test for Y2K problems, except in those days we did have Virtual Machines like we have now! Cheers, Gavin