Multiplex下，RLV (row level versioning) 开启的话，只有协调节点能用于write, 其他节点都只能是read only。 


RLV需要建立单独的RLV表空间，表需要特别指定是RLV表，RLV Store是一个in-memory store . RLV允许用户同一时间
在一个表进行更新操作，非RLV表是表级锁定，并行更新是不行的。 


RLV Store会定期自动与IQ main store合并in-memory内容，
 

Symptom
The row-level versioning (RLV) store is an in-memory store for high-performance row-level updates. If a table is registered for RLV storage, then all LOAD TABLE, INSERT, UPDATE, and DELETE commands write directly to the RLV store.


Multiple connections can make simultaneous updates to different rows of an RLV-enabled table. In the IQ main store, only one connection can write to a table at one time.


The RLV store periodically, and automatically, merges its in-memory contents with the IQ main store, although you can change merge preferences. You can trigger a manual merge when desired.


With in-memory row-level versioning (RLV) for SAP? Sybase? IQ, more than one user can modify the same table concurrently, users can wait for transaction locks instead of having to retry, and a hybrid storage model optimizes data write-access, without sacrificing read-access performance.


Resolution
IQ Simplex Database
           The following steps show how to create an RLV enabled dbspace and table, insert data, and then merge the RLV store into the IQ main store in a simplex database.