Blogs by

Stefan Koehler

Introduction This is just a short blog post about a simple DTrace script (dtrace_kghal_pga_code), that i recently wrote and published due to a PGA memory leak troubleshooting assignment. A client of mine noticed a major

Introduction This blog post is inspired by a question from an attendee of Sigrid Keydana’s DOAG 2015 conference session called “Raising the fetchsize, good or bad? Exploring memory management in Oracle JDBC 12c“. Basically it

Introduction The idea for this blog post started a few weeks ago when i had to troubleshoot some Oracle database / SQL performance issues at client site. The SQL itself included several views and so

Introduction The idea for this blog post is based on a recent Twitter discussion with Martin Berger, Martin Bach and Mauro Pagano about revealing SQL Plan Directive details for an existing cursor as walking through

Introduction Last week the DOAG 2014 conference took place in Nuremberg and it was a blast with a lot of useful presentations and especially great conversations and meet ups with Oracle friends. I had a

Introduction A long time has gone since my last blog post on SCN in March 2014, but i was quite busy with Oracle RAC implementations and troubleshooting performance issues in the last month. It was

Introduction This is a short blog post about another query transformation (check my first blog post [Oracle] DB Optimizer Part VIII – Looking under the hood of query transformation (done by CBO) with simple real

Introduction This is a short blog post about a nasty bug (#14607573) in PL/SQL procedure DBMS_STATS.COPY_TABLE_STATS, that i troubleshot in a non SAP application environment at client site last week. It is finally fixed by

Introduction In the first part of the “Adaptive Query Optimization” series we looked at the feature set called “Adaptive Plans”, which is completely new in Oracle 12c. However Adaptive Query Optimization consists of two feature

Introduction Last Saturday i got a phone call from a SCN member who found me due to my blogs and postings on SCN (thanks to SCN for the new client 🙂 ). He told me