| From | Sent On | Attachments |
|---|---|---|
| Tatsuya Kawano | Apr 28, 2010 7:40 am | |
| Stack | Apr 28, 2010 9:42 am | |
| Ryan Rawson | Apr 28, 2010 9:41 pm | |
| Tatsuya Kawano | Apr 29, 2010 1:33 am | |
| Todd Lipcon | Apr 29, 2010 9:36 am | |
| Guilherme Germoglio | Apr 29, 2010 9:58 am | |
| Michael Segel | Apr 29, 2010 1:08 pm | |
| Tatsuya Kawano | Apr 30, 2010 9:31 am | |
| Tatsuya Kawano | May 8, 2010 4:21 pm |
| Subject: | Unique row ID constraint | |
|---|---|---|
| From: | Tatsuya Kawano (tats...@snowcocoa.info) | |
| Date: | Apr 28, 2010 7:40:03 am | |
| List: | org.apache.hadoop.hbase-user | |
Hi,
I'd like to implement unique row ID constraint (like the primary key constraint in RDBMS) in my application framework.
Here is a code fragment from my current implementation (HBase 0.20.4rc) written in Scala. It works as expected, but is there any better (shorter) way to do this like checkAndPut()? I'd like to pass a single Put object to my function (method) rather than passing rowId, family, qualifier and value separately. I can't do this now because I have to give the rowLock object when I instantiate the Put.
=============================================== def insert(table: HTable, rowId: Array[Byte], family: Array[Byte], qualifier: Array[Byte], value: Array[Byte]): Unit = {
val get = new Get(rowId)
val lock = table.lockRow(rowId) // will expire in one minute try { if (table.exists(get)) { throw new DuplicateRowException("Tried to insert a duplicate row: " + Bytes.toString(rowId))
} else { val put = new Put(rowId, lock) put.add(family, qualifier, value)
table.put(put) }
} finally { table.unlockRow(lock) }
} ===============================================
Thanks,
-- 河野 達也 Tatsuya Kawano (Mr.) Tokyo, Japan
twitter: http://twitter.com/tatsuya6502





