No problem! In this case, insertion order is the same as natural order, so I think a LinkedHashMap is probably a better choice for this particular use case.
Here's a great SO post about the differences between HashMap, TreeMap and LinkedHashMap. http://stackoverflow.com/questions/2889777/difference-between-hashmap-linkedhashmap-and-sortedmap-in-java On Fri, Sep 13, 2013 at 9:29 AM, John <johnnyenglish...@gmail.com> wrote: > Hi, thanks for your quick answer! I figured it out by my self since the > mailing server was down the last 2hours?! Btw. I did option 1. But I used > a LinkedHashMap insead. Do you knows whats the better choice? TreeMap > or LinkedHashMap? > > Anyway thanks :) > > > 2013/9/13 Pradeep Gollakota <pradeep...@gmail.com> > > > Thats a great observation John! The problem is that HBaseStorage maps > > columns families into a HashMap, so the sort ordering is completely lost. > > > > You have two options: > > > > 1. Modify HBaseStorage to use a SortedMap data structure (i.e. TreeMap) > and > > use the modified HBaseStorage. (or make it configurable) > > 2. Since you convert the map to a bag, you can sort the bag in a nested > > foreach statement. > > > > I prefer option 1 myself because it would be more performant than option > 2. > > > > > > On Fri, Sep 13, 2013 at 7:31 AM, John <johnnyenglish...@gmail.com> > wrote: > > > > > I have created a HBase Table in the hbase shell and added some data. In > > > http://hbase.apache.org/book/dm.sort.html is written that the datasets > > are > > > first sorted by the rowkey and then the column. So I tried something in > > the > > > HBase Shell: http://pastebin.com/gLVAX0rJ > > > > > > Everything looks fine. I got the right order a -> c -> d like expected. > > > > > > Now I tried the same with Apache Pig in Java: > > http://pastebin.com/jdTpj4Fu > > > > > > I got this result: > > > > > > (key1,[c#val,d#val,a#val]) > > > > > > So, now the order is c -> d -> a. That seems a little odd to me, > > shouldn't > > > it be the same like in HBase? It's important for me to get the right > > order > > > because I transform the map afterwards into a bag and then join it with > > > other tables. If both inputs are sorted I could use a merge join > without > > > sorting these two datasets. So does anyone know how it is possible to > get > > > the sorted map (or bag) of the columns? > > > > > > > > > thanks > > > > > >
