Oracle Team

Spectre/Meltdown on Oracle Public Cloud UEK – PIO

By Franck Pachot . 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 $NF}' | sort | uniq -c 43 {CVE-2017-5715} 16(…)

Automatic Data Optimization Part II : StorageTiering

By Mouhamadou Diaw 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(…)

Automatic Data Optimization Part I : Compression Tiering

By Mouhamadou Diaw Nowadays data are increasing more and more. And some challenges we can face can be how to reduce storage costs and how to improve performance. With Oracle 12c, the feature Automatic Data Optimization (ADO) can help us.

Spectre and Meltdown, Oracle Database, AWS, SLOB

By Franck Pachot . 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)(…)

Keep your orapw password file secure

By Franck Pachot . This is a small demo I did when I've found a database password file (orapw) lying around in /tmp with -rw-rw-rw- permissions, to show how this is a bad idea. People think that the orapw file(…)

GoldenGate 12.2.0.2 installation in a Grid infrastructure12cR2

This post is a demonstration on how to deploy a fully supported Oracle GoldenGate as cluster resources. We are going to use the Oracle Grid Infrastructure Agents, called XAG to integrate the GoldenGate instance within our cluster as a cluster(…)

12c Multitenant internals: PDB_PLUG_IN_VIOLATIONS

By Franck Pachot . In the previous post https://www.dbi-services.com/blog/12c-multitenant-internals-pdb-replay-ddl-for-common-users I've done some DDL on a common user to show how this is replayed later for PDBs that were not opened at that time. But what happens(…)

12c Multitenant internals: PDB replay DDL for common users

By Franck Pachot . In multitenant, you can create common Users, Roles, and Profiles. You create them in CDB$ROOT, with the CONTAINER=ALL clause (which is optional because it is the only possible value when connected to CDB$ROOT) but they are(…)

Drop PDB including datafiles may keep files open

By Franck Pachot . I like that Oracle drops the datafiles from the operating system when we remove them from the database (with drop tablespace or drop pluggable database) because I don't like to have orphean files remaining in the(…)

12cR2 Subquery Elimination

By Franck Pachot . More and more we can see crazy queries generated by ORM frameworks or BI query generators. They are build to be easily generated rather than being optimal. Then, the optimizer has to implement more and more(…)