On Tue, Jan 18, 2011 at 2:41 PM, David Boxenhorn <da...@lookin2.com> wrote: > Thanks, Aaron, but I'm not 100% clear. > > My situation is this: My use case spins off rows (not columns) that I no > longer need and want to delete. It is possible that these rows were never > created in the first place, or were already deleted. This is a very large > cleanup task that normally deletes a lot of rows, and the last thing that I > want to do is create tombstones for rows that didn't exist in the first > place, or lengthen the life on disk of tombstones of rows that are already > deleted. > > So the question is: before I delete, do I have to retrieve the row to see if > it exists in the first place?
Yes, in your situation you do. > > > > On Tue, Jan 18, 2011 at 11:38 AM, Aaron Morton <aa...@thelastpickle.com> > wrote: >> >> AFAIK that's not necessary, there is no need to worry about previous >> deletes. You can delete stuff that does not even exist, neither batch_mutate >> or remove are going to throw an error. >> All the columns that were (roughly speaking) present at your first >> deletion will be available for GC at the end of the first tombstones life. >> Same for the second. >> Say you were to write a col between the two deletes with the same name as >> one present at the start. The first version of the col is avail for GC after >> tombstone 1, and the second after tombstone 2. >> Hope that helps >> Aaron >> On 18/01/2011, at 9:37 PM, David Boxenhorn <da...@lookin2.com> wrote: >> >> Thanks. In other words, before I delete something, I should check to see >> whether it exists as a live row in the first place. >> >> On Tue, Jan 18, 2011 at 9:24 AM, Ryan King <r...@twitter.com> wrote: >>> >>> On Sun, Jan 16, 2011 at 6:53 AM, David Boxenhorn <da...@lookin2.com> >>> wrote: >>> > If I delete a row, and later on delete it again, before GCGraceSeconds >>> > has >>> > elapsed, does the tombstone live longer? >>> >>> Each delete is a new tombstone, which should answer your question. >>> >>> -ryan >>> >>> > In other words, if I have the following scenario: >>> > >>> > GCGraceSeconds = 10 days >>> > On day 1 I delete a row >>> > On day 5 I delete the row again >>> > >>> > Will the tombstone be removed on day 10 or day 15? >>> > >> > >
