An odd little anomaly showed up on the OTN database forum a few days ago where a query involving a table covered by Oracle Label Security (OLS) seemed to wrap itself into a non-mergeable view when written using traditional Oracle SQL, but allowed for view-merging when accessed through ANSI standard SQL. I don’t know why there’s a difference but it did prompt a thought about non-mergeable views and what I’ve previously called “conditional SQL” – (more...)
Here’s a surprising (to me) execution plan from 22.214.171.124 – parallel execution to find one row in a table using a unique scan of a unique index – produced by running the following script (data creation SQL to follow):
set serveroutput off set linesize 180 set trimspool on set pagesize 60 alter session set statistics_level = all; variable b1 number exec :b1 := 50000 select /*+ parallel (3) */ id, v1 from (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...)
This note is about a little detail I hadn’t noticed about the merge command until a question came up on the OTN database forum a few days ago. The question was about the impact of the clustering_factor on the optimizer’s choice of execution plan – but the example supplied in the question displayed an oddity I couldn’t explain. Here’s the code and execution plan as originally supplied:
MERGE INTO gtt_ord t1 USING X t2 ON (more...)
For my tests I've set up a 126.96.36.199 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...)
1. It doesnt work anymore (it worked on 11g) to simply rerun application (applies for 12.1.3 and 12.2.1), without stopping it and then running again. In most of the cases if you try to rerun application, some strange errors are returned or changes are not visible at (more...)
Slides are available on slideshare:
Sample application used for the demo, can be downloaded from here (it consists of three parts - WebSocker server implementation, ADF BC tester application to generate continuos DB updates and JET application) - Oracle JET Live List with WebSocket.
ADF application with live data DVT component (more...)
The reason for a tool like PerfSheet.js is to make the analysis of AWR data easier by providing a graphical interactive interface and by automating several repetitive steps of data extraction and chart preparation. Pivot charts provide a flexible and easy to use way to navigate (more...)
There is no question that massive data is being generated in greater volumes than ever before. Along with the traditional data set, new data sources as sensors, application logs, IOT devices, and social networks are adding to data growth. Unlike traditional ETL platforms like Informatica, ODI, DataStage that are largely proprietary commercial products, the majority of Big ETL platforms are powered by open source.
With many execution engines, customers are always curious about their usage (more...)