Unfortunately the way I am reading/writing data from/to parts of my table would be incompatible with this solution.
In any case, thank you very much for your time. On Aug 28, 2012, at 4:10, Mohit Anchlia <[email protected]> wrote: > Have you thought of making your row key as key+timestamp? And then you can > do scan on the columns itself? > > On Mon, Aug 27, 2012 at 5:53 PM, Ioakim Perros <[email protected]> wrote: > >> Of course, thank you for responding. >> >> I have an iterative procedure where I get and put data from/to an HBase >> table, and I am setting at each Put the timestamp equal to each iteration's >> number, as it is efficient to check for convergence in this way (by just >> retrieving the 2 last versions of my columns). >> >> Some amounts of my equations are the same through iterations, and I save >> them (serialized) at two specific columns of my table with timestamp equal >> to zero. The rest of my table's columns contain the (serialized) >> alternating results of my iterations. >> >> The thing is that the cached amounts are necessary to be read at each and >> every iteration, but it would not be efficient to scan all versions of all >> columns of my table, just to retrieve the previous iteration's results plus >> the initially saved cached amounts. >> >> For example, being at iteration 30 I would like to retrieve only columns 3 >> and 4 with timestamp 29 and columns 0 and 1 with timestamp 0. >> >> With the current HBase's API, I am not sure if this is possible and the >> solution I described at my previous message (by storing columns 0 and 1 at >> all timestamps up to 40 for example) seems inefficient. >> >> Any ideas? >> >> Thanks and regards, >> IP >> >> >> On 08/28/2012 03:33 AM, Mohit Anchlia wrote: >> >>> You timestamp as in version? Can you describe your scenario with more >>> concrete example? >>> >>> On Mon, Aug 27, 2012 at 5:01 PM, Ioakim Perros <[email protected]> >>> wrote: >>> >>> Hi, >>>> >>>> Is there any way of retrieving two values with totally different >>>> timestamps from a table? >>>> >>>> I am using timestamps as iteration counts, and I would like to be able to >>>> get at each iteration (besides the previous iteration results from table) >>>> some pre-computed amounts I save at some columns with timestamp 0, >>>> avoiding >>>> the cost of retrieving all table's versions. >>>> >>>> The only way I have come up with is to save the pre-computed amounts >>>> redundantly at all timestamps up to the maximum possible. >>>> >>>> Does anyone have an idea on a more efficient way of dealing with this? >>>> >>>> Thanks and regards, >>>> IP >>>> >>>> >>
