Ram, If I understand correctly, I think you can design your index such that you don't actually use the timestamp (e.g. everything gets put with a TS = 10 - or some other non-special, relatively small number that's not 0 as I'd worry about that in HBase ;) Then when you set maxVersions to 1, everything should be good.
You get a couple of wasted bytes from the TS, but with the prefixTrie stuff that should be pretty minimal overhead. If you do need to keep track of the timestamp you should be able to munge that back up into the column qualifier (and just know that that last 64 bits is the timestamp). Again a little more CPU cost, but its really not that big of an overhead. It seems like you don't really care about the TS though, in which case this should be pretty simple. Out of curiosity, what are people using for their secondary indexing solutions? I know there are a bunch out there, but don't know what people have adopted, what they like/dislike, design tradeoffs made and why. Disclaimer: I recently proposed a secondary indexing solution myself (shameless self-plug: http://jyates.github.com/2012/07/09/consistent-enough-secondary-indexes.html) and its something I'm working on for Salesforce - open sourced at some point, promise! -Jesse ------------------- Jesse Yates @jesse_yates jyates.github.com On Tue, Aug 28, 2012 at 12:24 AM, Ramkrishna.S.Vasudevan < ramkrishna.vasude...@huawei.com> wrote: > Hi All > > > > When we try to build any type of secondary indices for a given table how > can > one handle maxVersions in the secondary index tables. > > > > For eg, > > I have inserted > > Row1 - Val1 => t > > Row1 - Val2 => t+1 > > Row1 - Val3. => t+2 > > > > Ideally if my max versions is only one then Val3 should be my result If I > query on main table for row1. > > > > Now in my index I will be having all the above 3 entries. Now how can we > remove the older entries from the index table that does not fit into > maxVersions. > > > > Currently while scanning and the code that avoids the max Versions does not > give any hooks to know the entries skipped thro versions. > > So any suggestions on this, I am still seeing the code for any other > options > but suggestions welcome. > > > > Regards > > Ram > >
