How To Gather Exadata Statistics ?

Very quick note on gathering of Exadata statistics. 


Gathering Exadata specific system statistics ensure the optimizer is aware of Exadata scan speed.

Accurately accounting for the speed of scan operations will ensure the optimizer chooses an optimal execution plan in a Exadata environment. 

Following command gathers Exadata specific system statistics

SQL>exec dbms_stats.gather_system_stats(‘EXADATA’);


Lack of Exadata specific stats can lead to less performance optimizer plans.

Action / Repair:

To see if Exadata specific optimizer stats have been gathered, run the following query on a system with at least BP18 or BP8 Oracle software. 

Exadata Patching - Compute Node

In earlier posts we have seen how to patch infiniband switch and Cell Server. 

Well, now let's continue with Database Server patching which is pending since long time.

Patching on Database server can be performed serially or in parallel using DCLI utility. utility is used to perform the database server patching

What utility does?

  • Stop/unlock/disable CRS for host restart
  • Perform LVM snapshot backup of / filesystem
  • Mount yum ISO image and configure yum
  • Apply OS updates via yum
  • Relink all Oracle homes for RDS protocol
  • Lock GI home and enable CRS upon host restart


Exadata Cell Services Administration

There are multiple services runs on Exadata cell server which need to administer on multiple occasion. i.e maintenance, upgrade, monitoring. Here we have listed down the commands to manage each cell service.

  • Check the status of all CELL services

#service celld status


#cellcli -e list cell attributes rsStatus, msStatus, cellsrvStatus detail

  • Start all CELL services

#service celld start


#cellcli -e alter cell startup services all

  • Stop all CELL services