Re: Change varchar column

Madison Pruet wrote: > "Mark" <kbl@net-yan.com> wrote in message news:<brq3mc$243e$1@news.hgc.com.hk>... > >>Dear all, >> >>During a table schema migration task, I unloaded data from a table, drop the >>table and re-create the table with changed some column from varchar(10) to >>varchar(255), then re-load the original data back to the new table. >> >>We found space used increased from 1GB to 1.5GB for that table. >> >>Anyone know why. > > > How did you measure the table space? If you are simply checking the > npused and you also loaded the table in an empty dbspace, then it is > possible that as extents were being added that full extents were > allocated simply because the space was otherwise empty. > > When a new extent is allocated, if the existing dbspace does not > currently have enough contigeous space to allocate a full extent, then > we will still allocate what we can. The order of allocation is 1) > empty space after the last allocated extent, 2) the next extent size, > 3) what ever we can get. So if the space is available for a full > extent allocation, then we would have allocated that space. > > It might be worth it to include the oncheck -pe of the dbspace to get > some idea as to how the space was allocated to figure out the why. > >>Thanks, >>Mark Outstanding in-place alters?? oncheck -pT from before - humm tricky now you have done it;)