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#DOAG2017
The discussions about the technologies we love. With Bryn about my tests on the MLE and the fact that I compared very different things, running a recursive function on different datatype (integer vs....
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WebLogic – SSO/Atn/Atz – How to enable debug logs
Let’s say that you have an application deployed on a WebLogic Server and that the SSO/Atn/Atz (SSO/Authentication/Authorization) isn’t working or throwing a 4xx error code like ‘401 – Unauthorized’ or...
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DBVISIT from Oracle to Postgres
As I regularly work on Oracle and PostgreSQL, I decided to test the replication from Oracle to PostgreSQL using the Dbvisit Replicate tool. Dbivisit Replicate does not use Oracle logminer ot triggers...
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DOAG 2017: Automation in progress
A week ago, I had the chance to be speaker at the DOAG Konferenz 2017 in Nürnberg. It’s sometimes hard to find time to be at the conferences because the end of year is quite busy at customers. But...
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Oracle docker image from docker store
Did you notice that each time you want to download the Oracle binaries from the OTN website (for non-production usage) you have to click on the “Accept License Agreement”? This is because you have to...
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Running the Oracle Client on a Raspberry Pi
What are the possibilities to use a Raspberry Pi computer as an Oracle client? Besides other things I’ll show a possibility in this Blog to run the fat/thick Oracle Client on a Raspberry Pi! REMARK:...
View ArticleSpectre and Meltdown, Oracle Database, AWS, SLOB
Last year, I measured the CPU performance for an Oracle Database on several types of AWS instances. Just by curiosity, I’ve run the same test (SLOB cached reads) now that Amazon has applied all Spectre...
View ArticleAutomatic Data Optimization Part II : StorageTiering
In first a previous blog, we saw how Automatic Data Optimization can be used to compress data under predefined conditions. In this blog we will see that another possible action with ADO is to move data...
View ArticleORACLE 11g to 12c RMAN catalog migration
This is a small migration demo of a 11g catalog (RCAT11G) to a new 12c catalog (RCAT12c). Demo databases environments have been easily managed thanks to DBI DMK tool. oracle@vmreforadg01:/home/oracle/...
View ArticleRMAN debugging during catalog import
In this post I would like to share how I have been able to troubleshoot and solve a catalog import issue using RMAN debug function. As we can see, the error message provided by RMAN is not very...
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Spectre/Meltdown on Oracle Public Cloud UEK – PIO
The Spectre and Meltdown is now in the latest Oracle UEK kernel, after updating it with ‘yum update': [opc@PTI ~]$ rpm -q --changelog kernel-uek | awk '/CVE-2017-5715|CVE-2017-5753|CVE-2017-5754/{print...
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Spectre and Meltdown on Oracle Public Cloud UEK – LIO
In the last post I published the strange results I had when testing physical I/O with the latest Spectre and Meltdown patches. There is the logical I/O with SLOB cached reads. Logical reads I’ve run...
View ArticleExplain Plan format
The DBMS_XPLAN format accepts a lot of options, which are not all documented. Here is a small recap of available information. The minimum that is displayed is the Plan Line Id, the Operation, and the...
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Testing Oracle SQL online
Want to test some DDL, a query, check an execution plan? You need only a browser. And you can copy-paste, or simply link, your test-case in a forum, a tweet, an e-mail, a tweet. Here is a small list...
View ArticleResult Cache: when *not* to use it
I encountered recently a case where result cache was incorrectly used, leading to high contention when the application encountered a peak of load. It was not a surprise when I’ve seen that the function...
View ArticleJAN18: Database 11gR2 PSU, 12cR1 ProactiveBP, 12cR2 RU
If you want to apply the latest patches (and you should), you can go to the My Oracle Support Recommended Patch Advisor. But sometimes it is not up-todate. For example, for 12.1.0.2 only the PSU is...
View ArticleServer process name in Postgres and Oracle
Every database analysis should start with system load analysis. If the host is in CPU starvation, then looking at other statistics can be pointless. With ‘top’ on Linux, or equivalent such as process...
View ArticleV$MYSTAT delta values
Here is a little script I use from time to time to look at V$MYSTAT values and displaying on one line a set of statistics with their delta value between two calls. The first script, _mystat_init.sql,...
View ArticleFull page logging in Postgres and Oracle
In my opinion, the volume of logging (aka redo log, aka xlog, aka WAL) is the most important factor for OLTP performance, availability and scalability, for several reasons: This is the only structure...
View Article(DESCRIPTION_LIST=(DESCRIPTION=(ADDRESS_LIST=(FAILOVER=YES)(LOAD_BALANCE=NO)
Do you have complex connection strings with DESCRIPTION_LIST, DESCRIPTION, ADDRESS_LIST, ADDRESS and a nice combination of FAILOVER and LOAD_BALANCE? You probably checked the documentation, telling you...
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