Sybase IQ Single Writer?

Question

I've heard a number of my colleagues make reference to the fact that Sybase IQ can only have a single writer. I'm struggling to find documentation on the web that either confirms or denies this so would someone be able to set the record straight in this regard?

What findings I have made lead me to think that perhaps on IQ 12 you were only allowed a single writer but on IQ 15 you are allowed a single writer per table? Is this true.

Any clarification would be much appreciated.

Thanks

Answer 1

Sybase IQ 12.7 only supports a single writer node but multiple reader nodes. Sybase IQ 15 allows both multiple writer and reader nodes. The writer nodes have full write access to the database and there are no restrictions at the table level.

Thanks Mark DeLaFranier Sybase, Inc.

Answer 2

Mark was answering your question in the context of multiplexing. Multiplexing is when you have many nodes on separate hosts that can breakup workloads between those nodes. In this type of IQ environment, there can only be 1 "write" node that disseminates table changes to the SAN that feeds all the other nodes. IE your ETL process would write data via your "write" node, but all the read nodes are available for computation/analytics.

However, I think your question had to do with the unique way Sybase IQ handles changes to the data inside a table. It has a unique way of updating/deleting/inserting records into a table, which is table "versioning". Since IQ is a columnar store not a row store, it actually applies your changes in a "new" version of the table you are modifying, then on commit, merges the changes into the original table.

This means only 1 process should be making changes to a table at a time.