1- Connect to the database in a test environment, isolated from the rest of users from production environment. with IBExpert or another database manager. Only one connection.

2- Monitor tha database with Sinatica Monitor to get number of active transactions, attachments and statements. At this moment only 1 connection is showed in Sinatica. 2 statements that are querys to system tables, I supose form IBExpert connection, 0 awaiting GC and 1 awaiting Sweep. 

3- Run a query SELECT * FROM CALENDAR WHERE EVENT_ID=132465 which only returns a record. I did not COMMIT that. 

4- Now SINATICA shows how AWAITING GC is increasing by 1 or 2 every second. In a minute it shows more than 100 Awaiting GC. 

5- COMMIT and now SINATICA shows AWAITING GC is again 0. 

I did the same thing with EMS SQL MANAGER and the result is the same. Leaving an interesting transaction on a single record table generates a big amount of garbage.