Re: RCubes

"abombss" <abombss_at_hotmail.com> wrote in message news:<j3wL9.383238$QZ.58704_at_sccrnsc02>...
> I have been doing some investigating about data warehousing and I wanted to
> ask this groups opinion about the idea of RCubes. It looks like Sybase is
> the only vendor using this approach, from what I understand it is a way to
> denormalize your data but not experience the typical data explosion with
> traditional RDBMS using a start schema. Sybase IQ stores data by column
> rather than by row. All columns are compressed and indexed using different
> bit wise techniques so lookups based on range and aggregates are still very
> quick.
>
> Has anyone had experience with Sybase ASE IQ Multiplex, or does this idea
> sound promising.
>
> The funny thing is, a couple weeks ago, prior to learning about IQ, I kicked
> around the exact same idea of storing data by columns and using bits to save
> space. However, I couldn't get past the problem of high cardinality data,
> but I guess Sybase did.
>
> Cheers,
>
> Adam

We are using Sybase IQ Multiplex - and it's a dream! IQ does indeed store data by column instead of rows - this is the kind of thing you can do in a pure DSS-environment. IQ is not appropriate for OLTP-applications.

You can expect performance increases in the range 3-20 times for most DSS-type of queries. IQ uses a "snapshot versioning" approach for changes to data - an update of 10 million rows will be almost as fast as an insert, with no special rollback/log-area to consider.

There is no maintenance of indexes in IQ - you do not have to run "update statistics" in order for the index to be useful. IQ allows many types of indexes, depending on what the column is used for, e.g. low-cardinality, medium-cardinality, summarised columns, join columns. This means that you have to have a good grasp for what the data is used for up front, but later on you do not need to maintain these indexes in any way. IQ compresses data before it is written to disk-with only the default index in place - the compression is 40-60%. Even with specialised indexes on some columns, you can be sure that IQ will only use a fraction of what a traditional RDBMS would use.

IQ Multiplex is an architecure which allows IQ to scale almost 100% linearly by putting in a new SMP_server box. This architecture is dependent on a SAN-type of storage solution.

Highly recommended for data warehousing!

Regards,
Bjorn Bentzen
Lindorff Received on Wed Dec 18 2002 - 15:27:09 CET