Re: ALTER FRAGMENT

Sahrul Hidayat wrote: > > Dear All, > > Question about this subject, > > 1. How ALTER FRAGMENT work, All rows are read then written into the new dbspace (or original dbspace if that's what you specify), and the original table is dropped. > 2. What we have to take care before do ALTER TABLE, i.e dbspace, log ?. You'll need enough free space in the dbspace for the new table (even if you're not moving dbspace), and sufficient logical log space. The process, which is of course logged, is done as a single transaction, so you must have enough log space to avoid a long transaction. > 3. Do we need to recalculate first and next extent before perform alter > fragment. ? If you're using this technique to reduce the number of extents in your table, then yes, you should alter the next extent size first. You can't alter the first extents size. > 4. What about if i.e the number of extent above 30, it will reduce to 0 or > at least below 8 after perform alter fragment ? possible or not ?. Things haven't gone too well if the number of extents is zero! Depending upon the size you choose for the next extent you could reduce it to as few as two. Try choosing next extent size as 1/3 of the exisitng space allocation; you'll end up with a table in 4 or 5 extents, but without a ridiculously high next extent size and thus wasted space. > 5. What we have to do to maximize the result of alter fragment ?. ????? Neil Truby Londis Holdings London, UK