Introduction: performance troubleshooting of a slow query using parallel query execution in a Hadoop cluster
The idea for this post comes from a performance troubleshooting case that has come up recently on our database services. It started with a user reporting slow response time from a query (more...)
About six months ago, when I was in the OUGN Spring Conference, someone asked me how they can let developers access to performance tuning pages on Enterprise Manager Cloud Control 13c. He said that they granted full administrator privileges to the developers so they could access the performance page but it’s not acceptable. He also mentioned that they didn’t need to grant full administration privilege to the developers’ EM users while they were using (more...)
Logging is a very useful feature of WebLogic.
Unfortunately the log levels, which are set after a clean install of WebLogic or some of the Fusion Middleware product creates a lot of noise and therefore it costs I/O performance.
Additional after analyzing an issue with logging often resetting the log level is forgotten.
Here you get a script to reset the log levels at regular intervals or after a trace session.
#!/usr/bin/python execfile('get_environment.py') (more...)
In order to achieve that a variation of Jonathan Lewis' good old "kill_cpu" script got executed. In principle each thread performed (more...)
As usual the latest version can be downloaded here.
This version comes only with minor changes, see the change log below.
Here are the notes from the change log:
- Finally corrected the very old and wrong description of "wait times" in the script comments, where it was talking about "in-flight" wait events but that is not correct. ASH performs a "fix-up" (more...)
- Who integrates Forms and ADF?
- Java Plugin to be Discontinued. Consequences for Oracle Forms.
- Why Yet Another Web Framework? Oracle JET.
- Forms and ADF and JET - Business Integration Patterns
- Forms Developer's perspective: life after learning (more...)
For my tests I've set up a 188.8.131.52 single instance database using "4 (more...)
Oracle 12c Unified Auditing is a brand new feature in the latest Oracle version which consolidates database level auditing records into a single location. DBAs can access the audit information from the view UNIFIED_AUDIT_TRAIL for all kind audit records, and they are
SQL> select distinct COMPONENT from all_unified_audit_actions; COMPONENT ---------------------------------------------------------------- Direct path API RMAN_AUDIT Database Vault XS Label Security Datapump Standard FineGrainedAudit 8 rows selected.
UNIFIED_AUDIT_TRAIL is a view owned by SYS and a public (more...)
I recently encountered this brilliant post on Medium that describes some best practices for CSS.
While APEX does a lot of this for you, I think it's worth a read by all developers. Even applying basic naming conventions can make code easier to read and understand.
There was also a section on performance that described an issue that my previous (more...)
I wanted to go to Hotsos Symposium for quite some time, having heard so many great topics from there for years. And every time I was a bit lazy to think about what I can talk about. Apparently I thought that everything I know is well covered elsewhere, so why would I be accepted. Plus all these complexities of budget, getting a visa, travel arrangements, jet lag, and personal matters in between. Last year, when (more...)
A few weeks ago, I was asked to give a private session about In-Memory database vs. traditional persistent databases. I created an hour-long session explaining the basics of database systems, how in-memory systems work, and when to use each of the systems.
One of the questions I got (and answered) was about persistent (regular) database cache mechanism – and I felt this is a good opportunity to write about Oracle 12c new feature – the (more...)
I likened what I learned to Tom Kyte's essay (Asktom->Resources->Presentations->FalseKnowledge.htm) on Correlation vs Causation. The essence was that things change over time, and we can't always trust authorities on the topic, and we must always test in our own environments. This aligns with skepticism in general, and (more...)
This change can make a big impact in the execution time of PL/SQL as it's processed at compile time instead of interpreted at runtime.
Plug-ins can be wonderful black boxes and consumers may not care (more...)