Tuning on Ivan Luminaria

Oracle on Linux: the kernel parameters nobody configures

Tue, 24 Feb 2026 08:03:00 +0100

The client was a logistics company running Oracle 19c Enterprise Edition on Oracle Linux 8. Sixty concurrent users, a custom ERP application, about 400 GB of data. The server was a Dell PowerEdge with 128 GB of RAM and 32 cores.

The complaints were vague but persistent: “The system is slow.” “Morning queries take twice as long as two months ago.” “Every now and then everything freezes for a few seconds.”

AWR, ASH and the 10 minutes that saved a go-live

Tue, 10 Feb 2026 08:03:00 +0100

Friday, 6:40 PM. I already had my jacket on, ready to leave. The phone buzzes. It’s the project manager.

“Ivan, we have a problem. The system is crawling. The go-live is tomorrow morning.”

It’s not the first time I’ve received a call like that. But the tone was different. This wasn’t the usual vague complaint about slowness. This was panic.

I reconnect to the VPN, open a session on the client’s Oracle 19c database. First thing I do is a quick check:

Oracle Partitioning: when 2 billion rows no longer fit in a query

Tue, 23 Dec 2025 08:03:00 +0100

Two billion rows. You do not reach that number in a day. It takes years of transactions, movements, daily records piling up. And for all that time the database works, queries respond, reports come out. Then one day someone opens a ticket: “the monthly report takes four hours.”

Four hours. For a report that six months earlier took twenty minutes.

It is not a bug. It is not a network issue or slow storage. It is the physics of data: when a table grows beyond a certain threshold, the approaches that worked stop working. And if you did not design the structure to handle that growth, the database does the only thing it can: read everything.