Ok, I think I've understood it from messing around a bit on my own with the guidance here. My issue was thinking I needed to know the exact ID of the row prior to the one I need compacted, which in my project's case is not possible, but through some scan operations I've found a way that will work.
Thank you for the assistance! On Mon, Feb 27, 2023 at 4:53 PM Ed Coleman <edcole...@apache.org> wrote: > Compactions work on splits / tablets so you will need to compact the > tablet that contains the row. > > Tablets correspond to split points, and the rows between the split points > are allocated to a single tablet. During a compaction the tablet will > process all of the rows in that tablet and write a single file containing > the rows for that tablet that pass the compaction filters and that do not > contain a deletion marker. > > With a sample table id=3, name = ns1.tbl2 and split points at aaa, bbb, > ccc, ddd, and remainder - I can examine the compaction counters by scanning > the metadata table. > > scan -t accumulo.metadata -b 3; -e 3~ -c srv:compact > 3;aaa srv:compact [] 2 > 3;bbb srv:compact [] 2 > 3;ccc srv:compact [] 2 > 3;ddd srv:compact [] 2 > 3< srv:compact [] 2 > > Then, run a compaction for split ccc using: > > compact -w -t ns1.tbl2 -b bbb~ -e ccc > > results in: > > scan -t accumulo.metadata -b 3; -e 3~ -c srv:compact > 3;aaa srv:compact [] 2 > 3;bbb srv:compact [] 2 > 3;ccc srv:compact [] 3 > 3;ddd srv:compact [] 2 > 3< srv:compact [] 2 > > The begin row of the compaction (bbb~) specifies everything that sorts > after after the split point bbb. This may help if you want to confirm > that you compacted the correct range. > > On 2023/02/27 19:44:53 Jonathan Allison-Pacheco wrote: > > Hi, I'm working on a project where we are needing to initiate a > compaction > > upon deleting an entry or set of entries. Looking at the > > TableOperations.compact method, it asks for `start` and `end` parameters, > > which are meant to include all tablets contained between the ones where > > those two rows exist, not including the start; such that (start, end]. > > > > This is a bit confusing to my interpretation, as if I need to run a > > compaction where a single row was involved, the method suggests it will > > compact the tablets between row+1 and row. Is that interpretation > correct, > > and if so, is that a proper way of utilizing this method? > > > > If not, what is the intended way of performing this type of task? > > > > Thank you, > > Jonathan Allison-Pacheco > > jpachec...@gmail.com > > >
