Alter Table on 41 million rows (2G):

Hi all, Background Info : Informix ver 7.22 UC4, HP-UX 10.20. I need to alter a table which has about 41 million rows ( 2Gig data ), basically changing the data type of one single column. This table has 40 fragments ( don't ask me why ) My question is as follows:- a. What are the factors that influence the performance of this query ? b. What do I to speed up the process ? c. How does setting it as a PDQ process compare it to running it as a normal process with PSORT_NPROCS set to an appropriate value d. Would running the query generate 40 parallel session ( for 40 fragments ), or do I have to force it in some way ? TIA Sujata ***************************************** Sujata Soman E-Mail: ssoman@omm.com O'Melveny & Myers, Los Angeles ******************************************