Slow query in DB2 due to Cartesian

Recently one developer came to me complaining poor sql performance and here is how I investigated the issue. Our environment: AIX 7.1 DB2 9.7.0.7 db2top -d dbname ConnTime..: 15:10:01.316 UOW Start.: 15:10:01.322 Appl name.: db2bp DB2 user..: CAIJI OS user…: caiji Agent id..: 62181 Coord DBP.: 0 Coord id..: 46105 Client pid: 26149284 Hash joins:… Continue reading Slow query in DB2 due to Cartesian

Heartbeat and multicast in redhat HA add-on

https://access.redhat.com/solutions/165433 How do I configure cluster nodes to use a dedicated heartbeat interface? https://access.redhat.com/articles/40051 Red Hat Enterprise Linux Cluster, High Availability, and GFS Deployment Recommended Practices It is highly recommended to separate the private network for cluster heartbeat from the application network. This should be done wherever possible. Red Hat Clustering in Red Hat Enterprise… Continue reading Heartbeat and multicast in redhat HA add-on

Recreating and restore controlfiles

Controlfile contains important information regarding instance and media recovery and here is how to understand its important role in several scenarios. My environment: OS: Redhat Linux 6.3 x86_64 DB: Oracle 11.2.0.3 Single instance 1 Control file contains backup information. [oracle@bcmsdbs01 bin]$ sqlplus / as sysdba SQL*Plus: Release 11.2.0.3.0 Production on Wed Nov 9 10:08:48 2016… Continue reading Recreating and restore controlfiles