anwers inline On Thu, Oct 29, 2009 at 5:24 PM, learningtapestry <[email protected]>wrote:
> > I am evaluating if HBase is right for a small prototype I am developing. > > Please help me understand a few things: > > 1. Can I do something like this in RDBMS -- "select * from table WHERE > column LIKE '%xyz%'" > You can create ValueFilters and scan through a table. But there is no query language as such. > 2. How should we place constraints? For example, if I have a Users table, > and one column is "login_name". How can I ensure that no two people create > the same login name? Is there a constraint I can place or something > similar? > It has to be in your application. Nothing in hbase gives this feature afaik > > 3. Is there something with HBase tables that I CANNOT do? If there is, what > is the strategy I have to use? > There is no concept of relational data. Its a different way of thinking about data. Everything is denormalized. For details, read the BigTable paper. > > 4. For something not possible with HBase today, can I simply use the > MapReduce framework that comes with Hadoop over the HBase tables? > What do you mean? You can surely write MR jobs that talk to HBase but thats not a workaround to RDBMS kind of stuff. If you need RDBMS kind of functionality, maybe HBase is not for you. > > Thanks in advance > -- > View this message in context: > http://www.nabble.com/HBase----unique-constraints-tp26123147p26123147.html > Sent from the HBase User mailing list archive at Nabble.com. > >
