This is a "feature" of SQL Server: it will use up as much memory as it can get its hands on if no other process is using the memory. It gives it back if other applications start using more memory.

See article K00000059 in the adTempus knowledge base for more information, though this article needs to be updated. It states that the 3.x database script sets the option to limit memory, but this is not correct. We don't recommend limiting the memory because this can decrease SQL Server and therefore adTempus performance.

We have done tests in the past to demonstrate that SQL Server does in fact give back the memory and it therefore should not affect system performance.