Also, you might want to take a look at Apache Phoenix if you want to "play" with composite keys without having to do all the coding...
2014-08-27 11:04 GMT-04:00 Ted Yu <[email protected]>: > Sanjiv: > Is country code of fixed width ? > > If so, as long as country is the prefix, it would be sorted first. > > Cheers > > > On Wed, Aug 27, 2014 at 8:00 AM, @Sanjiv Singh <[email protected]> > wrote: > > > Hi JM, > > > > Thanks for link... I agree with you that i can be done when key is an > > integer. > > > > Reason why i am asking for custom KeyComparator is that Something key is > > not just integer or some value , it can be of composition of multiple > > values like <COUNTRY><CITY> where key is made up of two values, one is > > COUNTRY and other is CITY. > > > > The way i wanted to order first them by COUNTRY , then by CITY. > > > > How can we do the same ? > > > > > > Hope that I have taken correct example, emphasizes my use-case. > > > > > > Regards > > Sanjiv Singh > > Mob : +091 9990-447-339 > > > > > > On Wed, Aug 27, 2014 at 5:42 PM, Jean-Marc Spaggiari < > > [email protected]> wrote: > > > > > Hi Sanjiv!!!! ;) > > > > > > If you want your keys to be ordered as Integers, why do you not simply > > > store them as Integers and not as Strings? HBase order the rows > > > alphabetically, and you can not change that. Yes you can implement a > key > > > comparator if you want but I don't think it's going to change anything > to > > > this situation. > > > > > > You might want to take a look at this: > > > http://hbase.apache.org/book/rowkey.design.html > > > > > > Just put your values that way: > > > > > > int myKey = 22000; > > > Put put = new Put(Bytes.toBytes(myKey)); > > > > > > And that will solve your ordering problem. > > > > > > JM > > > > > > > > > > > > > > > 2014-08-27 6:09 GMT-04:00 @Sanjiv Singh <[email protected]>: > > > > > >> Hi All, > > >> > > >> As we know, All rows are always sorted lexicographically by their row > > >> key. > > >> In lexicographical order, each key is compared at binary level, byte > by > > >> byte and from left to right. > > >> > > >> See the example below , where row key is some integer value and output > > of > > >> scan show lexicographical order of rows in table. > > >> > > >> hbase(main):001:0> scan 'table1' > > >> ROW COLUMN+CELL > > >> 1 column=cf1:, timestamp=1297073325971 ... > > >> 11 column=cf 1:, timestamp=1297073337383 ... > > >> 11000 column=cf1 :, timestamp=1297073340493 ... > > >> 2 column=cf1:, timestamp=1297073329851 ... > > >> 22 column=cf1:, timestamp=1297073344482 ... > > >> 22000 column=cf1:, timestamp=1297073333504 ... > > >> 23 column=cf1:, timestamp=1297073349875 ... > > >> > > >> I want to see these rows ordered as integer, not the default way. I > can > > >> pad > > >> keys with '0' to get a proper sorting order(i don't like it). > > >> > > >> I wanted to see these rows sorted as integer , not just as output of > > scan > > >> OR get method , but also to store rows with consecutive integer row > keys > > >> in > > >> same block. > > >> > > >> Now the question is : > > >> > > >> - Can we define our own custom KeyComparator ? > > >> - If Yes , can we enforce it for PUT method ? so that rows would > be > > >> stored as new KeyComparator. > > >> - Can we plug this comparator duriong SCAN method to change order > of > > >> > > >> result rows ? > > >> > > >> Hope, i have explained the proplem well, seeking for your valuable > > >> response on it. > > >> > > >> > > >> Regards > > >> Sanjiv Singh > > >> Mob : +091 9990-447-339 > > >> > > > > > > > > >
