Compressed OOPs (OOP – ordinary object pointer) is a technique reducing size of Java object in 64 bit environments. HotSpot wiki has a good article explaining details. Downside of this technique is what address uncompressing is required before accessing memory referenced by compressed OOPs. Instruction set (e.g. x86) may (more...)
Got a question: What will happen a running curosr got invalidated? SQL execution will fail or invalidation is not at all possible?
There are two components for an executing cursor. A session cached cursor (private area where row source are getting processed) in PGA and sharable execution plan (shared excution (more...)
Today was speaking at Oracle Coherence SIG at London.
Below you can find slide deck from my presentation.
In this post, I would like to share some knowledge about optimizing indexes in Oracle Coherence.
Normally you should not abuse queering features of your data grid and, hence, you are unlikely to ever need to tune indexing/queering (besides choosing which indexes to create). But sometimes, you really need to (more...)
create table t
rownum as id
, date '2000-01-01' + rownum - 1 as some_date
, cast(date (more...)
This is a first articles in series, where I would like to study effect of various HotSpot JVM options on duration of STW pauses associated with garbage collection.
This article will study how number of parallel threads affects duration of young collection Stop-the-World pause. HotSpot JVM has several young GC (more...)
This is the last post in this series and I’ll not introduce anything new here, but rather just summarise the changes explained and talk a bit about the value the solution delivers to the organisation.
Let’s first review the situation we faced before implementing the changes.
The cost of writing (more...)
OraLatencyMap v1.1 is now available (more...)
In my work among other things I tune and tweak solutions for EXADATA. Today I’ll write about a big improvement we achieved with a process that moves data from the operational tables to the ones where the history is stored.
This will not be a technical post. While I (more...)
Context: Oracle (since version 11gR1) exposes (more...)
You can download the latest version here.
In addition to many changes to the way the information is presented and many other smaller changes to functionality there is one major new feature: XPLAN_ASH now also supports S-ASH, the free ASH implementation.
If you run XPLAN_ASH in a S-ASH repository owner schema, it will automatically detect that and adjust accordingly.
Note: This post is about diagnosing real life scenario caused by direct path decision change on 18.104.22.168 which already covered by Tanel Poder on his awesome Optimizer statistics-driven direct path read decision for full table scans (_direct_read_decision_statistics_driven) post
If you already read and know how to (more...)
Here one day before deadline, I have entered almost my entire current catalog of presentations for consideration in the Oracle OpenWorld 2013 agenda. One new for this year: “Worst Oracle ADF Project Ever”
If you would like me to speak at one of your events, the following are the presentations (more...)