ADVISE

Hi Gurus, Today I have faced a problem. We have seen there is lot of table which extent size is more that 50. So we had decided to change the extent size. I have seen there is a table which is occupying 5 extents thru oncheck -pT command. But that table does not have any row. After dropping that table and recreating that table it is showing only 1 extent. That table everyday fills up for purging purpose after that all data get removed. What I know when any table fill up then it physically grows but after all data removal it can't understand that there is not any data. It shows only earlier picture. Is there any command by which I can get actual picture what extent is actually being used ? Sorry for poor english. Regards. Sandip Samanta

On Tue, 14 Sep 99 16:29:41 +0530, SANDIP SAMANTA <samanta@ccu-sn.IN.DHL.COM> wrote: > > >Hi Gurus, > >Today I have faced a problem. We have seen there is lot of table >which extent size is more that 50. So we had decided to change the >extent size. I have seen there is a table which is occupying 5 >extents thru oncheck -pT command. But that table does not have any >row. After dropping that table and recreating that table it is >showing only 1 extent. > >That table everyday fills up for purging purpose after that all data >get removed. What I know when any table fill up then it physically >grows but after all data removal it can't understand that there is >not any data. It shows only earlier picture. Is there any command by >which I can get actual picture what extent is actually being used ? When data is added to a table that has filled it's current extent(s), another extent is allocated to it. If data is then deleted from that table, the extents it had are still allocated to it. This is why it is a very good idea to sensibly plan the amount of space each table might need, and assign that when it is created (by using the FIRST EXTENT and NEXT EXTENT commands in the create table statement). Where you have a table that grows quickly and is then purged, try and estimate the maximum size it might reach before purging, and create the table with a large enough first extent to hold it. Obviously this may tie up a lot of disk space, but you will have to balance that against not having to frequently de-fragment. HTH, Richard.