extent allocation of alter fragment

Hi, Can someone tell me how does "alter fragment" allocate extents while doing the following: alter fragment on table <tablename> init fragment by round robin in dbspace1, dbspace2, dpspace3 The table is very big, 28 GB and it uses several 2-gig chunks in each fragmented dbspace. Is there a way which I can change the initial extent size? Thanks Roger XU Database Administrator Dr Pepper Bottling Company of Texas 2304 Century Center Blvd. Irving, TX 75062 (972)721-8337

Roger Xu wrote: > > Hi, > > Can someone tell me how does "alter fragment" allocate extents while doing > the following: > > alter fragment on table <tablename> init fragment by round robin in > dbspace1, dbspace2, dpspace3 The same as every other Informix command that allocates space. The initial extent size of each fragment is allocated in the first free extent large enough to hold it. As more extents are required the engine attempts to allocate them contiguous with the last extent allocated in that fragment, if possible the extents are 'compressed' into a single larger extent. > The table is very big, 28 GB and it uses several 2-gig chunks in each > fragmented dbspace. Right, since extents cannot span multiple chunks there will be at least as many extents as chunks needed to supply the required space in each dbspace. > Is there a way which I can change the initial extent size? Not without dropping/unloading the table but if this table is alone in its dbspaces there should be only one extent per chunk after compression. If other tables exist reorging them to collect free space into larger extents and collapse each table into a minimum of extents improves the likelihood that the next round of reorgs will result in only one or two extents per chunk. Art S. Kagel