Infrastructure at your Service

All posts by Franck Pachot

Franck Pachot
Technology Leader
Principal Consultant

OCM 12cFranck Pachot has 20 years of experience in Oracle databases. Through his expertise as a DBA, Oracle expert, data architect, and performance specialist, he is able to cover all database areas: architecture, data modeling, database design, tuning, operation, and training. Franck knows how to enable an efficient collaboration between the developers and the operational team when it comes to troubleshooting issues or performance tuning.

RSSOracle ACEOracle ACE Franck is Oracle Certified Master (OCM 12c), Oracle ACE Director and proud member of Oraworld-team and Oak Table.

Next public appearance:
C15LV
Las Vegas (US), Apr 25th

From Transportable Tablespaces to Pluggable Databases
12.2 Multitenant New Security Features to Clarify DevOps and DBA role separation
DOAGDB18
Düsseldorf (DE) , May 14th


12cR2/18c security features to clarify DBA role in DevOps
POUG
Sopot (PL), Sept. 7th

Join Methods: Nested Loop, Hash, Sort, Merge, Adaptive


Franck Pachot

Happy New Year 27, 104, 2015 and 2558

By | Database management, Oracle | No Comments

calendar today tomorrow message —————– —— ——— ————– Arabic Hijrah 1436 1436 English Hijrah 1436 1436 Gregorian 2014 2015 Happy New Year Japanese Imperial 0026 0027 Happy New Year Persian 1393 1393 ROC Official 0103 0104 Happy New Year Thai Buddha 2557 2558 Happy New Year   According to Oracle calendars… SQL> l 1 with cal as ( 2 select ‘Arabic Hijrah’ name from dual union all select ‘English Hijrah’ from dual 3 union all…

 
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Franck Pachot

Oracle multitenant dictionary: object links

By | Database management, Oracle | 3 Comments

I’ve described Oracle 12c metadata and object links internals in a previous post. But before that, the first time I investigated on it, I made a wrong assumption because I was looking at AUDIT_ACTIONS which is not correctly implemented. That investigation came from a question on dba-village. And recently Ivica Arsov (@IvicaArsov) has made an interesting comment about AUDIT_ACTIONS object link table, so I’ll explain here what is special with it. AUDIT_ACTIONS Here is how…

 
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Franck Pachot

Creating a schema synonym in Oracle – an unsupported feature

By | Database management, Oracle | 3 Comments

Ivica Arsov (@IvicaArsov) has made an interesting comment about AUDIT_ACTIONS object link table. I’ll blog about it soon, but in the meantime when checking its definition in cataudit.sql it came upon the following: /* SCHEMA SYNONYMS will be added in 12g */ — insert into audit_actions values (222, ‘CREATE SCHEMA SYNONYM’); — insert into audit_actions values (224, ‘DROP SCHEMA SYNONYM’); which caught my attention. So this blog post is not about mulitenant but about Schema…

 
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Franck Pachot

Oracle lateral inline view, cursor expression and 12c implicit statement result

By | Database management, Oracle | No Comments

I’ll present here 3 ways to run a query for each result of another query. Let’s take an exemple: get all executions plan (select from dbms_xplan.display_cursor) for each of my queries (identified from v$sql). The 90’s way was to run the first query, which generates the second queries into a spool file, and execute that file. Here are easier ways, some of them coming from 12c new features lateral join and implicit statement result. Test…

 
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Franck Pachot

Oracle 12c: Can we disable logging for DML?

By | Database management, Oracle | No Comments

If we don’t mind about loosing our changes, then can we disable logging for DML? This is a question I’ve heard a lot. Ok, you don’t need to recover your changes but Oracle may want to recover the consistency of its datafiles anyway. And that’s why datafiles blocks changed though the buffer cache always generate redo. But yes, in 12c you can do DML and generate only minimal redo. All DML: even updates and deletes….

 
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Franck Pachot

SQL*Plus COPY Command is back as BRIDGE

By | Database management, Oracle | No Comments

Did you ever use the COPY command in sqlplus? It’s very old, and documentation says : The COPY command is not being enhanced to handle datatypes or features introduced with, or after Oracle8i. The COPY command is likely to be deprecated in a future release. Deprecated? But it is back, with a new name, in the new SQL Developer based SQL*Plus (currently called sdsql in beta) SQL*Plus COPY Documentation is here. Let’s show how to…

 
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Franck Pachot

Oracle 12c: comparing TTS with noncdb_to_pdb

By | Database management, Oracle | No Comments

How to migrate from non-CDB to CDB? Of course all known migration methods works. But there is also another solution: upgrade to 12c if necessary and then convert the non-CDB to a PDB. This is done with the noncdb_to_pdb.sql which converts a non-CDB dictionary to a PDB one, with metadata and object links. But do you get a clean PDB after that ? I tested it and compared the result with same database migrated by…

 
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Franck Pachot

When Oracle resets session statistics

By | Database management, Oracle | No Comments

During our Oracle 12c New Features workshop I had a very good question about whether the session statistics are reset or not when doing ALTER SESSION SET CONTAINER. My initial thought was that they were not reset because it’s the same session (same SID and SERIAL#). But when I’m not 100% sure about something, I test it. And once again, it proves that even the instructor can learn something new when giving a workshop, thanks…

 
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Franck Pachot

Oracle 12c privilege analysis rocks

By | Database management, Oracle | 4 Comments

12c came with a very nice feature: privilege analysis. You don’t know which privileges are required? then just grant DBA, run your application, and check which minimal privileges are needed. And today, I’ve discovered how it is very powerful: you can even see privileges used internally, even when not done by SQL, and even not documented. It starts like that, with a question from Vladimir Sitnikov (who publishes very interesting stuff from his twitter account)…

 
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Franck Pachot

Oracle locks: Identifying blocking sessions

By | Database management, Oracle | 5 Comments

When you have sessions blocked on locks, you probably have all information about the waiters (they call you and anyway their waiting session is visible in v$session our ASH). But you usually need to get enough information that help to identify the blocker. Here is a query I use to get that quickly, based on V$WAIT_CHAINS Here is the result I want to get: session wait event minutes USER PRO ———————– ———————————————– ——- —- —…

 
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