SequenceExists has low performance

I’m trying to migrate our plain old sql files to liquibase 2.0.3 and I’ve observed a big performance problem when sequenceExists is called. It takes up to 270252ms (yes more than 4 minutes) to execute the changeset with this precondition whereas it takes around 50ms for other changesets.
As I have several sequences that I check, it takes too much time ;o)

I think it might be related to , but I may be mistaken.