Does anybody here read concepts manual? There is sufficient material about extents and space allocation. Concepts manual for your version of Oracle can found at: http://tahiti.oracle.com Oracle uses RTFM algorithm with the strong "F" to distribute data among the datas files. -- Mladen Gogala Ext. 121 -----Original Message----- From: Marquez, Chris [mailto:cmarquez@xxxxxxxxxxxxxxxx] Sent: Tuesday, October 18, 2005 10:49 AM To: Yavor_Ivanov@xxxxxxxx; Oracle Mailing List; oracle.tutorials@xxxxxxxxx Subject: RE: DATAFILE?? I don't know...thought about it, never cared to investigate, never *needed* to know. But what is Oracle algorithm for disbursing data amongst available datafiles?