INFORMIX & DATA TYPE SERIAL: Questions

Hi all, Some questions on how Informix handles the "Serial(n)" data type. 1. How is the "next serial number" calculated ? why do I sometimes see different behaviour(s), for eg, if we have 5 rows, numbered 1 thru 5, and I delete #5, and insert a new row :- On some occasions, the new serial number is #5, and on others, it is #6 - Why ? 2. I once deleted all the rows in a table with a serial number field, and when I tried to insert new rows, the serial number had not been updated to 0, ie the new numbers picked up from the old set. 3. Now, when you create a new table with a serial type column, if you do not specify an initial number ( for eg serial(2) vs serial ), does that default to 0 ?? 4. Are the "holes" in a serial type column ever filled/re-used ?? TIA Sujata ***************************************** Sujata Soman E-Mail: ssoman@omm.com O'Melveny & Myers, Los Angeles ******************************************