The TravelTransactionLog ("TTL") table dates back to the deep past of SuperOffice, when the Internet was a nice idea and crappy/expensive hotel phone lines were the reality. Being able to take the database with you was a real power feature. Even better, you took only a subset that was relevant to you, saving expensive megabytes on your little harddisk.
NetServer still notes changes in TTL, and it's still valuable as a record of changes being made - at least to tables that were part of the Travel system. Most of this logging is relatively cheap and worth keeping. However, there are several special events that complicate the code and have some performance overhead.
These are the changes that would, in the old days, have influenced the filters used to define the subset of the database that users would take with them: changes to contact.associate_id (and a few obscure tables only used for the Area Management configuration in Travel). The other category is logging of per-field changes on Udef tables. Both of these can result in additional database traffic (because we need to know the previous value), and we can't write the actual change until that information has been secured.
In the TTL table, these events have event ID's higher than 4864. The basic events for Insert (4352, 0x1100), Update (4608, 0x1200) and Delete (4864, 0x1300) will be kept; but we want to stop logging all other events.
If you have no idea what I'm writing about here - fine! No problem! But if this causes cold sweat and incipient panic then I need to know.
Cheers,
Marek