Hi Jason, This is very good reference. I read it from begin to the end and learned a lot. Thanks and have a good weekend.
regards, Lin On Tue, Aug 7, 2012 at 2:00 AM, Jason Frantz <jfra...@maprtech.com> wrote: > Lin, > > Looks like your questions may already be answered, but you might find the > following link comparing "traditional" columnar databases against > HBase/BigTable interesting: > > > http://dbmsmusings.blogspot.com/2010/03/distinguishing-two-major-types-of_29.html > > -Jason > > On Sun, Aug 5, 2012 at 8:03 PM, Lin Ma <lin...@gmail.com> wrote: > > > Thank you for the informative reply, Mohit! > > > > Some more comments, > > > > 1. actually my confusion about column based storage is from the book > "HBase > > The Definitive Guide", chapter 1, section "the Dawn of Big Data", which > > draw a picture showing HBase store the same column of all different rows > > continuously physically in storage. Any comments? > > > > 2. I want to confirm my understanding is correct -- supposing I have only > > one column family with 10 columns, the physical storage is row (with all > > related columns) after row, other than store 1st column of all rows, then > > store 2nd columns of all rows, etc? > > > > 3. It seems when we say column based storage, there are two meanings, (1) > > column oriented database => en.wikipedia.org/wiki/Column-oriented_DBMS, > > where the same column of different rows stored together, (2) and column > > oriented architecture, e.g. how Hbase is designed, which is used to > > describe the pattern to store sparse, large number of columns (with NULL > > for free). Any comments? > > > > regards, > > Lin > > > > On Mon, Aug 6, 2012 at 12:08 AM, Mohit Anchlia <mohitanch...@gmail.com > > >wrote: > > > > > On Sun, Aug 5, 2012 at 6:04 AM, Lin Ma <lin...@gmail.com> wrote: > > > > > > > Hi guys, > > > > > > > > I am wondering whether HBase is using column based storage or row > based > > > > storage? > > > > > > > > - I read some technical documents and mentioned advantages of > HBase > > is > > > > using column based storage to store similar data together to > foster > > > > compression. So it means same columns of different rows are stored > > > > together; > > > > > > > > > Probably what you read was in context of Column Families. HBase has > > concept > > > of column family similar to Google's bigtable. And the store files on > > disk > > > is per column family. All columns of a given column family are in one > > store > > > file and columns of different column family is a different file. > > > > > > > > > > - But I also learned HBase is a sorted key-value map in underlying > > > > HFile. It uses key to address all related columns for that key > > (row), > > > > so it > > > > seems to be a row based storage? > > > > > > > HBase stores entire row together along with columns represented by > > > KeyValue. This is also called cell in HBase. > > > > > > > > > > It is appreciated if anyone could clarify my confusions. Any related > > > > documents or code for more details are welcome. > > > > > > > > thanks in advance, > > > > > > > > Lin > > > > > > > > > >
