Oracle
Oracle is the database that shaped me professionally.
I have been working with it since 1996, and in nearly thirty years I have seen versions, paradigms and trends come and go — but the core of the engine has remained the same: solid, complex, unforgiving to those who do not know it deeply.
I have managed instances with a few hundred users and data warehouses with billions of rows. I configured Data Guard when it was still called standby database, I wrote PL/SQL when debugging meant DBMS_OUTPUT and patience, I designed partitioning schemes before they became a marketing deck feature.
Oracle is not a database you learn from tutorials.
You learn it from incidents, from migrations at three in the morning, from execution plans that change after a statistics update.
In this section I share what I have learned in the field: architecture, security, performance and the design decisions that separate an installation that works from one that merely survives.
Because with Oracle, knowing the syntax is not enough.
You need to understand how the engine thinks.
Oracle on Linux: the kernel parameters nobody configures
A client with Oracle 19c on Linux and disappointing performance. Default installation, no tuning. Huge Pages, semaphores, I/O scheduler, THP and security limits: everything that was missing — with the before-and-after numbers.
AWR, ASH and the 10 minutes that saved a go-live
Friday evening, the night before a go-live. Performance collapses. Using AWR and ASH I found a hidden full table scan in a stored procedure in under ten minutes — and the production release went ahead.
Users, Roles and Privileges in Oracle: Why GRANT ALL Is Never the Answer
A client where every application user connected as the schema owner with the DBA role. How I restructured the Oracle security model by applying the principle of least privilege — with real SQL, custom roles and Unified Audit.
Oracle Partitioning: when 2 billion rows no longer fit in a query
A client with a 2-billion-row transaction table and reporting queries that had gone from seconds to hours. How I solved it with Oracle partitioning — range, interval, partition pruning and local indexes.
From Single Instance to Data Guard: The Day the CEO Understood DR
An Oracle production database with no redundancy. A disk failure that brought everything to a halt for six hours. And the CEO's decision to invest in an Active Data Guard architecture with automatic switchover.