Andrej Pashchenko
@andrejsql.bsky.social
200 followers 98 following 15 posts
Data Engineer, Oracle Ace Pro ♠ blog.sqlora.com
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andrejsql.bsky.social
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...
Fix Optimizer Estimate Issues from Implicit Conversions #JoelKallmanDay
Learn how implicit RAW-to-VARCHAR2 conversions in Oracle break histograms, hurt optimizer estimates, and how to fix them safely.
blog.sqlora.com
andrejsql.bsky.social
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
andrejsql.bsky.social
How do I get the test data these days? My #Accenture colleague @cgohmannde.bsky.social explains. #makeit2025
Reposted by Andrej Pashchenko
danischnider.bsky.social
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
andrejsql.bsky.social
How can we help the Oracle optimizer to do better with function calls? @danischnider.bsky.social explains. #makeit2025
Reposted by Andrej Pashchenko
cgohmannde.bsky.social
After the keynote at #MakeITConf, my Accenture colleague @andrejsql.bsky.social shared some interesting insights of table merging.

@oracleace.bsky.social
Reposted by Andrej Pashchenko
danischnider.bsky.social
Conferences are always a chance to see my former colleagues of Trivadis again:

@andrejsql.bsky.social talking about table merging at #MakeIT2025
andrejsql.bsky.social
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...
MERGE and DML RETURNING clause in Oracle 23ai
Oracle 23ai finally supports MERGE … RETURNING! A long-awaited feature, but still hard to find in the docs.
blog.sqlora.com
andrejsql.bsky.social
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...
ORA-30926 in Oracle 23ai: What’s Changed?
Explore how Oracle 23ai improves MERGE behavior and error handling, replacing vague ORA-30926 message with clearer, smarter diagnostics.
blog.sqlora.com
andrejsql.bsky.social
Thank you! It is hard to calculate as I didn't start from zero. At least it took the time to watch the videos on mylearn.
andrejsql.bsky.social
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...
When Compression Expands: The Hidden Pitfalls of HCC
This post explores the behavior of Hybrid Columnar Compression (HCC) in Oracle Exadata while refreshing materialized views with atomic_refresh=true.
blog.sqlora.com
andrejsql.bsky.social
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 😃
andrejsql.bsky.social
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...
andrejsql.bsky.social
@danischnider.bsky.social explains the performance of views on the big stage of the #DOAG2024
andrejsql.bsky.social
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.
salvis.com
First session at #DOAG2024 by @andrejsql.bsky.social about SQL Macros. Lot of examples and ideas after a short introduction.
andrejsql.bsky.social
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