Hi Hari, What you are asking for is transactions. I'd say try to avoid it. HBase can only guarantee atomicity on the row level. So if you want something across tables and rows then you need to use for example ZooKeeper to implement a transactional support system- There is also THBase, which gives you that but is a) maintained by a contributor so may not always be current or updated at all b) is quite intrusive as it had to patch up the RegionServer code and c) has performance penalty - but then must will have that.
Rather implement this not as a "relational" and "normalized" set of tables but store the user and all his orders in on row. You can implement one ColumnFamily for the order and then go super wide on that. There are some papers out on the web (sorry, do not have the links handy) that address this topic. You will have to rethink the way you do things. Lars On Mon, Dec 6, 2010 at 6:22 AM, Hari Sreekumar <[email protected]> wrote: > Hi, > > Let's say I want to have a "Customer" (C) table and an "Orders" > table, and I want to have a column in C table which is a list of all order > Ids for that customer. How can I ensure that whenever a new order is > added/removed, the corresponding order list is also updated accordingly? Is > it possible to do this. and what would be the performance impact? > > Hari >
