Thanks. On Tue, Jan 18, 2011 at 3:55 PM, Sylvain Lebresne <sylv...@riptano.com>wrote:
> 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? > >>> > > >> > > > > >
