Urh Srecnik @usrecnik - Bluesky Profile

I dug into what happens during a regular Oracle login — LogMiner, redo dumps, and an undocumented parameter. Turns out every login generates a transaction.

blog.srecnik.info/the-hidden-c...

17.02.2026 15:11 — 👍 1 🔁 0 💬 0 📌 0

GitHub - usrecnik/asmfs: A read-only FUSE filesystem that exposes **raw** Oracle ASM files using internal APIs. A read-only FUSE filesystem that exposes **raw** Oracle ASM files using internal APIs. - usrecnik/asmfs

github.com/usrecnik/asmfs

11.01.2026 19:43 — 👍 0 🔁 0 💬 0 📌 0

my asmfs can now read Oracle ASM files directly from block devices using x$kffxp (no longer relying on dbms_diskgroup). Following post walks through how it works: using `x$kffxp` to figure out where each extent lives, then reading straight from disk.

blog.srecnik.info/reading-orac...

11.01.2026 19:42 — 👍 3 🔁 1 💬 1 📌 0

utl_recomp and Automatic Statistics Gathering When recompiling invalid objects—often after patches, upgrades, or invalid dependency chains—you might call utl_recomp.recomp_serial. Since it's a serial procedure, one could reasonably expect it to avoid any parallel or background job interaction. B...

Ever had utl_recomp.recomp_serial fail because it couldn't gather statistics concurrently? 🤔

Turns out recompilation still calls dbms_stats.gather_table_stats—which honors global concurrent stats preference.

Details:
blog.srecnik.info/utlrecomp-an...

03.12.2025 10:15 — 👍 0 🔁 0 💬 0 📌 0

Legacy Clients on 19c We've just migrated one of the last databases to 19c. The main area of concern for the client was that they were using rather old embedded devices, which had 11g client libraries and connect strings baked into their firmware. Here's the list of the m...

USE_SID_AS_SERVICE - or rather, don't unless you need to; here's a scenario from 11g upgrade when this came in handy (embedded devices with hardcoded connection strings).

blog.srecnik.info/legacy-clien...

10.11.2025 21:06 — 👍 0 🔁 0 💬 0 📌 0

Oracle Flashback Database Automatic Deactivation Today I learned that Oracle can disable the Flashback Database feature by itself automatically. Here's the reason - an excerpt from the alert log: ORA-38886: WARNING: Flashback database was disabled due to error when writing flashback database logs. ...

Oracle Flashback Database can apparently auto-disable itself on I/O errors. I did a few quick test cases about it as I didn't expect this behavior initially. You can read about my findings here:

blog.srecnik.info/oracle-flash...

26.09.2025 20:10 — 👍 0 🔁 0 💬 0 📌 0

ASMFS & dbms_diskgroup.read Here's what I've learned while trying to implement an ASMFS (which is an open-source GitHub project) and where my implementation fell short of my initial expectations. Initial Expectations I can access v$asm_file and v$asm_alias, which provide a comp...

I tried implementing ASM filesystem using dbms_diskgroup.read() and found some quirks.
Here's what I learned: blog.srecnik.info/asmfs-and-db...

17.08.2025 18:14 — 👍 0 🔁 0 💬 0 📌 0

Navigating Through Incarnations on a Physical Standby Database On Standard Edition

Ever had to navigate multiple incarnations on a physical standby database — on Standard Edition?

Here’s how to handle RESETLOGS and make the right incarnation visible (and usable) on standby.

blog.srecnik.info/navigating-t...

20.07.2025 22:46 — 👍 2 🔁 0 💬 0 📌 1

Why Are My Oracle Sessions Getting SIGSTOP’d? Finally, I encountered a case that couldn't be solved using traditional Oracle Database tools. I've been experimenting with eBPF for some time, and this is a real-world scenario from an Exadata environment where I needed eBPF to help me truly underst...

Ever seen Oracle sessions get "stuck" because their dedicated server process is in STOPPED state?
Here's how I traced such behavior - not to Oracle itself, but to a third-party library hooking into the DB process.

Full story: blog.srecnik.info/why-are-my-o...

08.06.2025 19:00 — 👍 0 🔁 0 💬 0 📌 0

I’m honored to be recognized as an Oracle ACE Associate in the @oracleace.bsky.social community.

Looking forward to continuing this journey and sharing more insights on Oracle technologies with all of you.

Big thanks to @monikalewandowska.bsky.social for the nomination!

05.03.2025 20:40 — 👍 8 🔁 0 💬 0 📌 0

Proxy Users & Schema Only Accounts Remember those MYAPP/MYAPP@MYDB logons? With all the security buzz and auditors out there, I thought of those as a thing of the past. This blog won't preach about the importance of strong passwords. Instead, I'll explain which capabilities of Oracle ...

In my latest blog post, I explore how to streamline user management with Proxy Users and Schema-Only Accounts in Oracle Database.
If database security and schema design are on your radar, take a look:

blog.srecnik.info/proxy-users-...

20.01.2025 18:52 — 👍 0 🔁 0 💬 0 📌 0

Oracle Native Network Encryption As I come across environments where SQL*Net is not encrypted I sometimes also notice that there are two common misconceptions about it: First, some are afraid that certificates must be involved and consequently maintaining a PKI infrastructure is de...

Did you know Oracle Native Network Encryption is available in all licensed editions of Oracle Database?
Here’s a quick how-to: blog.srecnik.info/oracle-nativ...

22.12.2024 18:22 — 👍 0 🔁 0 💬 0 📌 0

Introduction to JOIN LATERAL on Oracle Lateral join joins a subquery, which is executed as many times as there are rows in the leading table. Consider it as a kind of for-each loop. Most of, if not all, the problems it solves, can also be solved without lateral join (e.g. using analytic f...

You can read about "Introduction to JOIN LATERAL on Oracle" on my blog. It's sometimes overlooked feature which is available in Oracle since version 12c.

blog.srecnik.info/introduction...

07.12.2024 16:24 — 👍 0 🔁 0 💬 0 📌 0

Collecting SQL Plan Baselines on Standard Edition

Here's my blog post about Collecting SQL Plan Baselines
on Standard Edition:

blog.srecnik.info/collecting-s...

02.12.2024 19:28 — 👍 1 🔁 0 💬 0 📌 0

Urh Srecnik

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