BusinessObjects Board

Improving performance of the universe.

building semantic layer
#1

Hi!

Does anyone know how to fine tune a query using row count in the universe? I know people use this method to fine tune the query but don’t know how to :frowning:

Thanks for any input,

James

Jamesp :us: (BOB member since 2004-10-13)

Uncommitted Reads against SQL Server
#2

Nowadays most DBMS use a cost-based optimizer, which collects statistics about the tables to make a good decision for the execution path - for these the row count for tables set in Designer does not matter.

The row count for tables in Designer only matters for old rule-based optimizers.

Options to optimize universes for performance:

  • Derived tables with prompts
  • Database indexes
  • Partitioned tables
  • Aggregate Awareness
  • Index Awareness
  • Lookup tables for LOVs
  • Shortcut-joins
  • Array fetch size
  • Allowing dirty reads (a.k.a uncommited reads, etc.)
  • Using database optimizer hints
    …

Andreas :de: (BOB member since 2002-06-20)

#3

Hi,

I’m curious about the item “Allow dirty reads (uncommitted reads)” in Andreas’s post above. Andreas or anyone else, could you please elaborate?

Thanks,
Judy

JMulders :us: (BOB member since 2002-06-20)

#4

Source: http://www.jguru.com/faq/view.jsp?EID=721

See here for another source.

Andreas :de: (BOB member since 2002-06-20)

#5

Thanks Andreas. I’ll discuss with our users and DBA to see if this would be acceptable in our environment.

Thanks for the tip,
Judy

JMulders :us: (BOB member since 2002-06-20)