Oracle Database Administrator · Rome, Italy

Valentin Cojocaru

I started working as an Oracle DBA on 1 April 2022, at 21: it was my first job, at a multinational IT services company. Since then I have been running Oracle 11g, 12c and 19c databases, in test and production, on Linux, AIX and Windows.

I cover the whole lifecycle: single-instance and multitenant installations, upgrades and migrations to 19c, Data Guard with FSFO and Active Data Guard, backup and recovery with RMAN, performance analysis with AWR/ADDM, and security (Wallet, ACLs, connection allow-lists). With my team I also look after MariaDB and MySQL.

I document every significant task step by step, with commands, checks and a rollback plan. This site grew out of that habit: the same notes, stripped of customer data, so they can be useful to others too.

Career

read as an alert log

$ tail -f alert_valentin.loguptime 1689 days

2015–2020Diploma: IT technicianComputer Science & Telecommunications · I.T.I. Lattanzio, Rome.
2020-10University: Computer Science (not completed)Tor Vergata · left to start working straight away.
2021-11Completed: OCI Foundations 2021First Oracle certification (1Z0-1085-21).
2021-12Completed: 3 × Oracle Cloud SpecialistAutonomous Database · Database Services · Database Migration & Integration.
2022-04-01Starting ORACLE instance (normal)First day as an Oracle DBA, at 21.
2022-09Completed: AZ-900Microsoft Azure Fundamentals.
2022 →Database opened: READ WRITEProduction on 11g, 12c and 19c across Linux, AIX and Windows: incidents, patching, RMAN, AWR/ADDM, users, roles and security.
2022 →ALTER DATABASE SWITCHOVER TO STANDBYData Guard with 2 and 3 nodes, FSFO, observers and Active Data Guard; failover and switchover tests.
2022 →ALTER DATABASE … UPGRADEIn-place upgrades 11.2.4 / 12.1 / 12.2 → 19c; migration of databases hosting APEX applications via duplicate, then upgrade 11.2.3 → 11.2.4 → 19c; PDB unplug/plug; Data Pump.
2026ADMINISTER KEY MANAGEMENT …TDE with an external key manager, database-side support for a migration to AWS (DMS), MySQL 8.0 → 8.4 LTS upgrade.
2026-07Completed: AI Database FoundationsOracle AI Database Certified Foundations Associate (1Z0-1195-26).
2026-08Completed: OCI Architect AssociateTogether with OCI Foundations Associate 2026 (1Z0-1072-26 · 1Z0-1085-26).
NEXTALTER SYSTEM SET career_target='IT SYSTEMS ARCHITECT | SRE' SCOPE=SPFILE;Saved in the spfile: takes effect at the next restart. Working on it.

Skills

what I actually do

SQL> select comp_name, version, status from dba_registry;

COMP_NAME	VERSION	STATUS
-- ORACLE DATABASE
Oracle Database	11g · 12c · 19c	VALID
Oracle AI Database 23ai · 26ai	next step · AI Database Foundations	UPGRADING
Database installation	single instance · CDB/PDB · silent mode · runInstaller/DBCA	VALID
Installation standards	"one home, one or many DBs" profiles on Linux and AIX · post-install cleanup	VALID
Multitenant	PDB creation, manual too · plug / unplug	VALID
Grid Infrastructure · RAC · ASM	21c installation · srvctl/crsctl · ASM disks & diskgroups · cluster tests	VALID
Patching	OPatch · Release Update · one-offs · GI/RAC 19.11 → 19.21	VALID
Upgrades & downgrades	11.2.0.3 → 11.2.0.4 → 19c · 12.1/12.2 → 19c · AutoUpgrade · compatibility matrices	VALID
Database structure	redo logs · undo · tablespaces · control files · DB rename (nid)	VALID
Oracle Client · Gateway	client installs · db links to non-Oracle databases	VALID
Oracle APEX	upgrades & checks	VALID
Oracle TimesTen	operations & checks	VALID
Exadata Cloud@Customer	operations & incidents	VALID
-- HIGH AVAILABILITY & DR
Data Guard	installation & setup · 2 & 3 nodes · FSFO · observer · Active Data Guard	VALID
DR testing	switchover · failover	VALID
-- BACKUP & RECOVERY
RMAN	backup scripts · restore · recover · duplicate from active	VALID
Point-in-time recovery	tablespace PITR · recover table · datafile · control file · archive logs	VALID
Flashback	flashback table · recycle bin · restore point	VALID
Offline backups	begin / end backup	VALID
Environment refresh	production → test realignment with RMAN	VALID
Data Pump	expdp / impdp · cross-version	VALID
-- PERFORMANCE
SQL tuning	execution plans · plan history & forcing	VALID
AWR · ADDM	analysis · SYSAUX cleanup	VALID
Maintenance	index rebuilds · file system, alert log & listener log cleanup	VALID
-- SECURITY
Oracle Wallet · SSL/TLS	orapki · certificates	VALID
Transparent Data Encryption	external key manager	VALID
Kerberos	authentication	VALID
ACL · white list	network access to the database	VALID
Users · roles · profiles	privileges & password policies	VALID
-- MARIADB · MYSQL
MariaDB Enterprise	installation · my.cnf · stop/start	VALID
Galera Cluster · MaxScale	node management · sync issues · cluster stop/start	VALID
MariaDB upgrades & patching	version & release upgrades on Galera · RPMs & repositories	VALID
Backups & refreshes	mariabackup · mysqldump · production → test	VALID
MySQL	installation · users & grants · dumps & backups · slow query log	VALID
MySQL upgrades	8.0 → 8.4 LTS	VALID
-- SYSTEMS, CLOUD & OPERATIONS
Linux · AIX · Windows Server	database side · NFS/NAS file systems	VALID
Diagnostics	ADRCI · alert log · trace	VALID
Scripting & scheduling	shell · crontab · backup, setup and stop/start scripts	VALID
AWS	console · managed databases · DMS migration support	VALID
OCI · Azure	OCI Architect Associate · AZ-900	VALID
Oracle Enterprise Manager	monitoring	VALID
Ansible Tower · ChatOps	maintenance mode	VALID
My Oracle Support	opening & following SRs	VALID
On-call & war rooms	production incidents	VALID
Assessments & onboarding	new environments · handovers · decommissioning	VALID
SRE practices	in progress	UPGRADING

46 rows selected.

Where I'm heading

SQL> alter system set career_target = 'IT SYSTEMS ARCHITECT | SRE' scope = spfile;

System altered.

My goal is to grow into an IT systems architect or Site Reliability Engineer role: designing reliable infrastructure and data platforms, not just keeping them running.

The certifications I am taking and the guides on this site are steps in that direction.

Certifications

SQL> select * from dba_certifications order by end_date desc;

OCI Certified Architect AssociateOracle1Z0-1072-26 · Aug 2026 · 90%
OCI Certified Foundations AssociateOracle1Z0-1085-26 · Aug 2026 · 98%
AI Database Certified Foundations AssociateOracle1Z0-1195-26 · Jun 2026 – Jul 2026 · 73%
Microsoft Azure FundamentalsMicrosoftAZ-900 · Jun 2022 – Sep 2022
Autonomous Database Cloud 2021 Certified SpecialistOracle1Z0-931-21 · Sep 2021 – Dec 2021 · 70.9%
Cloud Database Migration & Integration 2021 Certified SpecialistOracle1Z0-1094-21 · Sep 2021 – Dec 2021 · 78%
Cloud Database Services 2021 Certified SpecialistOracle1Z0-1093-21 · Sep 2021 – Dec 2021 · 78%
OCI Foundations 2021 Certified AssociateOracle1Z0-1085-21 · Aug 2021 – Nov 2021 · 70%

8 rows selected.

Education

SQL> select * from dba_education;

University studies in Computer Science (not completed)University of Rome Tor Vergata · started Oct 2020 · left to start working as a DBA
Diploma in Computer Science & TelecommunicationsI.T.I. Lattanzio, Roma · Sep 2015 – Jun 2020 · 79/100

Languages

SQL> select value from v$nls_valid_values where parameter = 'LANGUAGE';

ITALIANC2
ENGLISHB2
ROMANIANnative
RUSSIANnative

-- off hours: dystopian novels and hiking