How most BW performance support messages are solved

As the fourth quarter of the year started everybody seems to check the goals that had been set for this year and what has already been reached. Looking back on the messages I worked on I found a very clear pattern, when the message was about BW on Oracle and performance. Most messages were solved … Continue reading How most BW performance support messages are solved

SAP Support case “FOR ALL ENTRIES disaster”

Last week a colleague from the WHM (data warehouse management) support team called me to get some assistance with a customer message he was processing. The customer complained about short dumps with the infamous "TSV_TNEW_BLOCKS_NO_ROLL_MEMORY" error, which is basically the way an ABAP work process reports that it ran out of memory. Checking the short … Continue reading SAP Support case “FOR ALL ENTRIES disaster”

Short note on Line Item and High Cardinality dimensions

One of the quotes I like most I learned from Tom Kyte from Oracle. It's one from Artemus Ward: "It ain't so much the things we don't know that get us into trouble. It's the things you know that just ain't so." This blog post is about one of those cases. A customer complained about … Continue reading Short note on Line Item and High Cardinality dimensions

Question to SAP Support “Why is partition pruning not working in my BW on Oracle?”

Welcome to the problem As usual understanding, the meaning and the scope of the question is key for the answer to this question, recently filed by a customer. So, what is the customer complaining about? What does he mean by "partition pruning"? It's a feature of the query optimizer to figure out, which partitions of … Continue reading Question to SAP Support “Why is partition pruning not working in my BW on Oracle?”

“Things change for the better” or “How I enhanced the Oracle DBMS software”

Unexpected Behavior Last week during an Oracle workshop with my primary support colleagues in the GSC Ireland I came across something new (at least to me). This alone is not worthy of writing even a short note, as it happens all the time, but this time I really thought "Wow - so there was an … Continue reading “Things change for the better” or “How I enhanced the Oracle DBMS software”

BW on Oracle: a performance hunch I see more and more often…

Ok, once again reproducing a problem takes a lot of (waiting-)time for the query to finish. In the meantime I can also just write a super-short-blog post about a pretty common BW-on-Oracle performance hunch: Inappropriate database optimizer statistics. (yes, 'inappropriate' not 'outdated'!) Usually, that means: if everything runs as it is supposed to, BW will … Continue reading BW on Oracle: a performance hunch I see more and more often…

Quick help for ORA-60 deadlock in BW systems

Today I re-learned a nice option to overcome ORA-60 problems with parallel data loading scenarios. As most of you will know (from reading note "84348 - Oracle-Deadlocks, ORA-00060" or Michael Braunsteins Blogs Chasing Oracle deadlocks part I - row level locks/Chasing Oracle deadlocks part II - block level locks or some other resource) the problem … Continue reading Quick help for ORA-60 deadlock in BW systems