Thanks! The fact that you are using a binary tree behind the scenes makes perfect sense. Btw, what do you use in the standalone (non native) implementation? Does it use a TreeMap?
On Tue, Nov 27, 2012 at 12:57 PM, Keith Turner <[email protected]> wrote: > > > On Tue, Nov 27, 2012 at 12:21 PM, Roshan Punnoose <[email protected]>wrote: > >> The <string> would most likely be a fixed set of strings that do not >> change over time. >> >> My question is if it is bad to use a reverse index timestamp in the row >> id? Will it cause problems with the tablet splitting, compaction, and >> performance if the data is always being sent to the top of the tablet? If I >> define a split as everything prefixed with <string>, then the ingest will >> go to one tablet, but then I add a reverse timestamp in the row, and that >> would mean I am always copying data to the top of the tablet. Will this >> cause performance issues? Or is it better to append to a tablet? >> > > I do not think it should matter. Inserts go into a C++ STL map on the > tablet server if using the nativemap. I think the implementation of that > is a balanced binary tree. So I do not think inserting at the beginning vs > the end would make difference. That being said, I do not think I have > tried this so I do not know if there would be any suprises. I would be > interested in hearing about your experiences. > > >> >> >> On Tue, Nov 27, 2012 at 11:51 AM, Keith Turner <[email protected]> wrote: >> >>> >>> >>> Keith >>> >>> On Tue, Nov 27, 2012 at 10:41 AM, Roshan Punnoose <[email protected]>wrote: >>> >>>> I want to have a table where the row will consist of "<string>-<reverse >>>> index timestamp>". But this means that the data is always being prefixed to >>>> the beginning of the row (or tablet if the row is large). Will this be a >>>> problem for compaction or performance? >>> >>> >>> Can you tell me more about what <string> is? For example is it a hash >>> or does it come from the set "foo1","foo2","foo3". How does it change >>> over time? I think the answer to your question depends on what <string> is. >>> >>> >>>> >>>> I don't know if I heard this correctly, but someone once mentioned that >>>> making the row id the direct timestamp could cause performance issues >>>> because data is always going to one tablet, but also because there is >>>> trouble splitting since it always appends to the tablet. Is this true, is >>>> it similar to what could happen if I am always prefixing to a tablet? >>>> >>> >>> Yes using a timestamp for a row could cause data from many clients to >>> always go to the same tablet, which would be bad for performance on a >>> cluster. >>> >>> >>>> >>>> Thanks! >>>> Roshan >>>> >>> >>> >> >
