Re: a couple of quick fragmentation questions

On Apr 4, 8:44 pm, "Jack Parker" <jack.park...@verizon.net> wrote: > I have to agree here. The cost of altering the fragmentation strategy will > undoubtedly be much higher than unloading/dropping/recreating/reloading with > HPL. > > When you alter a fragment and it requires data movement, that movement goes > through the logs and typically uses 3-6x the amount of space that your > fragment has. So if this is a large fragment (10GB) - count on using 60GB > of logical log space. > > No I do not recall if my experience included a table which was unlogged, my > impression is that it did not. This is certainly something I would test. > > j. > Yeah if the database is logged, then alter fragment will log everything. This would include the delete from the old fragment, the insert into the new fragment, and any index manipulation required. Additionally, it appears that the indexes on the newly createdfragments are created prior to the moving of the data, so it would be like doing a load on a table with the indexes in place, which would be slower then doing the load and then creating the index. Jacques