BI Data Analytics

   Below are some finding while testing done for Tableau against IBM Db2 on cloud: Tableau seems to work better when using standard model instead of custom sql. Union is having performance issues. In some cases using cross join gives better performance results  Multi-language label changes solution is not extensive and need to create multiple worksheet and formatting compared to Cognos Analytics where you can assign query at Page level to place calculated columns anywhere.

Since now IBM Cloud OPS team supports Cognos Environment and there is need to open ticket and have delays in response times to detect issues, we can set up Job to run some quick reports to run every 5 minutes. While scheduling, need to keep in mind Reports total tun time covers 3-4 minutes run time so that Job will keep running all the time. Exclude times in schedule where maintenance/backup going on.  Reports to be run in sequence so that it doesn't impact actual reports run by users. You can set Job run history to more time to see it on Page itself  You can set up to send an email via even after job completion to include run time. When you stop getting emails, it means there was an outage/issue in the environment. You can create Audit report to check mean, median and mode for Job run time performance to compare run times against.   This method can test dashdb and report run times consistency; however, actual navigational/interactive report run times can't b...

Changes in SQLs while migrating from Oracle to DB2 to improve performance: Instead of nvl or coalesce function use case statement Instead of using select clause within select statement, create joins with sub queries Don't use subqueries in where clause Creating small tables for required columns and joining them results in faster performance Use "AS" to qualify names Define Amount Type to decimal(15,2) to match with DB. They may be dropped while doing aggregations.

Below are issues identified  while working with IBM Cloud team PDF Font sizes are different. Fonts to be installed by IBM Audit DB not configured correctly. Extra set up done to change system Timezone to match with location Drill Through functionality not working. Interim Fix was provided having Multiple Data source Connections causing issue to work with reports having native sqls and based on data modules. Custom Controls path was changed making all reports using them not working.  Performance issues in running report. Environment moved to nearest location from original location. DASHDB ( Db2 Datawarehouse On Cloud)  performance tuning done for reports taking longer time compared to Oracle. Navigation to Cognos Administration is slow. Cache parameter is updated to improve on performance.