To start with :*netezza :*
- not a columnar db
- mix of olap & oltp
- not mmp db
- uses lots of memory for DB strucutres
- downtime for maintainance
The good stuff - excelent integration with SAS,R,SPSS - fast analitics - simple to install and maintain - excelent integration with BI/ETL tools - row-lelev security support - uses pk at load time
The bad stuff - is row store (means is I/O bound) - poor enterprise fit (PostgreSQL foundation) - memory hog when more then 10 concurent queries - upgrade is a big problem ,"fork lift" required. - no internal storage - data load is limited ot 4 concurent streams - poor export perf becouse of the single head node - space reclaim lock the table in full lock
Go for HP Vertica
Hope this helps !!