Andrej Pashchenko

#JoelKallmanDay #Oracle26ai introduces QUALIFY — a welcome addition to Oracle SQL that makes filtering on analytic function results much easier. But what happens under the hood? Query transformations and execution plans reveal a few surprises. blog.sqlora.com/en/oracle-26...

A question on my first Oracle 26ai JOIN TO ONE post made me look even closer. This time: the real CBO transformations behind the implicit LEFT OUTER JOIN — and the performance impact of the runtime checks. blog.sqlora.com/en/oracle-26... #OracleDatabase #Oracle26ai #SQL

A few months ago, Oracle 26ai introduced the new JOIN TO ONE syntax. After a first look during one of my Oracle 26ai trainings, I wanted to explore it further from a data warehouse perspective. Some thoughts and experiments: blog.sqlora.com/en/oracle-26... #Oracle26ai #SQL #DataWarehouse

With online stats gathering, Oracle AI Database captures stats when you use CREATE TABLE AS SELECT A direct path INSERT INTO ... SELECT into an empty table @andrejsql.bsky.social investigates its evolution And finds many restrictions are lifted 26ai

🌊💻 MakeIT 2026 & JCON Slovenia 2026 are almost here! Join the Oracle, Java, and open-source community in Portorož, Slovenia for three exciting days of learning, innovation, and networking. 🚀 📍 Portorož, Slovenia | 📅 May 27–29, 2026 🔗 makeit.si #OracleACE

New short blog series on Oracle 26ai CALENDAR functions. Part 2: execution context and the question — Do I still need a time dimension? #Oracle #SQL #26ai #DataWarehouse blog.sqlora.com/en/calendar-...

New short blog series on Oracle 26ai CALENDAR functions. Part 1: semantics and implementation nuances. #Oracle #SQL #26ai blog.sqlora.com/en/calendar-...

There are various ways to recall the wonderful conferences of the past year during the slower pace of the Christmas season, such as this one. Who can guess this beautiful place? 🙂 Merry Christmas and hope to see you there next year!

Learning from mistakes is important. Better: learn from others' mistakes. Even better: today we can learn from @danischnider.bsky.social 's ones #doag2025

Storing UUIDs as RAW values is more efficient than strings But RAW can lead to implicit conversions => poor row estimates If you're stuck with string comparisons @andrejsql.bsky.social shows how to improve row estimates with Extended stats Virtual columns

The long way of #JSON in #Oracle, from 12.1.0.2 until today. Now starting with 23ai and still 15 minutes left. Not bad! You can do it! #HrOUG2025 #HrOUG25

Tennis before the first session on day 3 of HrOUG with team „Awesome“ and „OMG“. It was great fun. Thanks! #HrOUG25 #HrOUG2025

#joelkallmanday We tend to forget that troubleshooting is mainly just about Clear and Calm thinking.. pdvfirstblog.blogspot.com/2025/10/simp...

New blogpost enesi.no/2025/10/uuid... #JoelKallmanDay #oracle

New post for #JoelKallmanDay! Ever wondered why the Oracle Optimizer sometimes ignores your histograms? Implicit data type conversions might be to blame. Here’s how to fix it without touching your SQL and with minimal schema impact. #Oracledatabase blog.sqlora.com/en/fix-optim...

Honored to speak at #HROUG2025 – celebrating its 30th anniversary in amazing Rovinj! 🎉 Huge thanks to the organizers for keeping this fantastic community going for 30 years! 🙏 Let’s put some old SQL myths to the test together! #Oracle #SQL #Optimizer #Accenture #OracleAce

How do I get the test data these days? My #Accenture colleague @cgohmannde.bsky.social explains. #makeit2025

Who will win? @andreakennel.bsky.social , @danischnider.bsky.social or #ChatGPT? We'll see.

I finish the first day of #MakeIT2025 like I started it: with a session of @andrejsql.bsky.social. This time he talks about parameterized views in Oracle

How can we help the Oracle optimizer to do better with function calls? @danischnider.bsky.social explains. #makeit2025

After the keynote at #MakeITConf, my Accenture colleague @andrejsql.bsky.social shared some interesting insights of table merging. @oracleace.bsky.social

Conferences are always a chance to see my former colleagues of Trivadis again: @andrejsql.bsky.social talking about table merging at #MakeIT2025

MERGE ... RETURNING is now supported in Oracle 23ai. In my view, it deserves more visibility in the documentation — it wasn’t easy to find. Even LLMs still claim it doesn’t exist (some go as far as inventing error codes). Read more: #Oracle23ai #SQL #MERGE #OracleDB blog.sqlora.com/en/merge-and...

Ten years after my first post on the quirks of MERGE and ORA-30926, I took a fresh look at how Oracle 23ai handles it. Clearer error messages, improved diagnostics, and fewer unnecessary restarts. Read the new blog post #Oracle23ai #SQL #MERGE @oracleace.bsky.social blog.sqlora.com/en/ora-30926...

Happy to share my new Oracle Certified AI Vector Search Professional certification! BTW, it is free until May 15 2025 #Oraclecertified #ConvergedDatabase catalog-education.oracle.com/pls/certview...

Did you know that refreshing HCC-compressed materialized views with atomic_refresh=true can multiply storage usage over time? Small details can have massive impacts. Read the new blog post. #Exadata #Oracle #HCC @oracleace.bsky.social blog.sqlora.com/en/when-comp...

The same topic, the same @danischnider.bsky.social, but something has changed, the stage dimension perhaps? Note: stage dimension is not a new term in data warehousing, Dani is speaking about 😃

Excited to speak at #UKOUGDiscover24! Do you also believe that collecting statistics in a data warehouse is not a ‘one size fits all’ approach? And that a targeted approach is part of your role as a data engineer? Join my session on 2 December at 16:00. See you there! ukoug.org/page/UKOUGCo...

@danischnider.bsky.social explains the performance of views on the big stage of the #DOAG2024

Mentioned you, your blog und linked to your package SQM_UTIL, @stewashton.bsky.social. Such package is a must have if you consider using SQL Macros. Thank you.

The wait is over: #DOAG2024 starts tomorrow in Nuremberg. Want to learn about some advanced techniques and concepts around the practical use cases of #SQLMacros in #oracledatabase? Join me in the very first slot at 8:30