THBase and ITHBase are officially supported components in 0.20.0 and will remain so in 0.21.0. Their presence in contrib/ is because they are not core functionality but that placement should not be construed as second class.
- Andy ________________________________ From: Keith Thomas <[email protected]> To: [email protected] Sent: Thursday, September 10, 2009 3:01:29 PM Subject: Re: Possible to set the results' sort method? Brilliant! That works perfectly. Where do I vote for this to be included in 0.21.0? :-) Clint Morgan-3 wrote: > > perhaps you would be interested in the tableindexed package. (Its in > transactional contrib, see doc in o.a.h.h.client.tableindexed, or look at > the tests). > > It will allow you to get a scanner whose results are ordered by a column's > values (If you have an index on that column). > > -clint > > On Thu, Sep 10, 2009 at 5:49 AM, Keith Thomas > <[email protected]>wrote: > >> >> >> >> stack-3 wrote: >> > >> > On Wed, Sep 9, 2009 at 7:52 PM, Keith Thomas <[email protected]> >> > wrote: >> > >> >> >> >> I think I'm looking at the same problem with HBase as Dingding Ye. I >> need >> >> to >> >> be able to retrieve a list of rows sorted by data in a column and I'm >> not >> >> sure how to go about it without resorting to performing the sort on >> the >> >> client which feels like I'm just giving up. >> >> >> >> >> > >> > s3> You want to sort rows in the table by other than the row key or is >> it >> > just >> > s3> that you want to sort the content of a row by other than its column >> > name? >> > >> > I want to sort by the content of a column in each row. >> > >> > s3> How big is the set you want to look at? Is it full table or some >> > subset of >> > rows? >> > >> > I am writing the data access layer, not the app itself. I have to >> conform >> > to a certain api. It is up to the application itself to use certain >> > limits, although I may impose configurable limits in my layer just to >> be >> > conservative in this brave new world I am exploring. Idelly I'd like to >> be >> > able to to both, i.e. retrieve a full table or a subset. I think that >> once >> > I've written the full table support I's worry about collecting just a >> > subset. >> > >> > >> >> My current thinking is to create a map class that outputs key/value >> pairs >> >> where the key is the field I want to sort upon and the value is row >> key. >> >> This way I will get nice sorted input going into my reduce class. I >> guess >> >> I >> >> would have to have once reduce class instance. >> >> >> > >> > s3> Why one reduce? Write your own partitioner and impose a total >> order? >> > Thanks, I will read up on this, thanks for the direction. >> > >> > >> > >> >> >> >> However, I am unclear how I can return the row keys and the families >> with >> >> their column data to the client from the reduce class. All the >> examples >> I >> >> have found so far write the results to files/tables whereas I want to >> >> return >> >> objects to a client. >> >> >> > >> > s3>Yeah.... bit tough making your client into a reduce sink (Can be >> done, >> > it >> > s3>just has to be available to the full cluster) >> > >> > I guess the thing I'm definitely completely stuck upon is how to get >> > something like Result back to the client when I' writing my own >> map/reduce >> > classes. >> > >> >> >> >> In the Hadoop Javadocs I notice a bunch of Comparators but as yet I've >> >> not >> >> figure out their purpose. If I spend the cycles understanding the >> purpose >> >> of >> >> these Comparators are they likely to be of help to me in formulating >> an >> >> alternate/better approach to that described above? >> >> >> > >> > >> > s3> In HBase all is lexicographically ordered. Tables are ordered by >> > rows. Row >> > s3> content is ordered by columns. >> > >> > Thanks >> > >> > St.Ack >> > >> > >> >> >> >> -- >> >> View this message in context: >> >> >> http://www.nabble.com/Possible-to-set-the-results%27-sort-method--tp20047852p25376341.html >> >> Sent from the HBase User mailing list archive at Nabble.com. >> >> >> >> >> > >> > >> >> -- >> View this message in context: >> http://www.nabble.com/Possible-to-set-the-results%27-sort-method--tp20047852p25382714.html >> Sent from the HBase User mailing list archive at Nabble.com. >> >> > > -- View this message in context: http://www.nabble.com/Possible-to-set-the-results%27-sort-method--tp20047852p25391773.html Sent from the HBase User mailing list archive at Nabble.com.
