Andrej Pashchenko
@andrejsql.bsky.social
Data Engineer, Oracle Ace Pro ♠
blog.sqlora.com
blog.sqlora.com
Reposted by Andrej Pashchenko
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
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
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.
buff.ly
November 4, 2025 at 12:02 PM
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
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
You can do it!
#HrOUG2025 #HrOUG25
October 17, 2025 at 10:35 AM
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
You can do it!
#HrOUG2025 #HrOUG25
Reposted by Andrej Pashchenko
Tennis before the first session on day 3 of HrOUG with team „Awesome“ and „OMG“. It was great fun. Thanks! #HrOUG25 #HrOUG2025
October 17, 2025 at 7:17 AM
Tennis before the first session on day 3 of HrOUG with team „Awesome“ and „OMG“. It was great fun. Thanks! #HrOUG25 #HrOUG2025
Reposted by Andrej Pashchenko
#joelkallmanday
We tend to forget that troubleshooting is mainly just about Clear and Calm thinking..
pdvfirstblog.blogspot.com/2025/10/simp...
We tend to forget that troubleshooting is mainly just about Clear and Calm thinking..
pdvfirstblog.blogspot.com/2025/10/simp...
Simplicity, Troubleshooting, #JoelKallmanday
TL;DR: You don't have to be a genius to solve problems. And there is no shame in not-knowing or not understanding all the geeky details. Ma...
pdvfirstblog.blogspot.com
October 15, 2025 at 7:20 AM
#joelkallmanday
We tend to forget that troubleshooting is mainly just about Clear and Calm thinking..
pdvfirstblog.blogspot.com/2025/10/simp...
We tend to forget that troubleshooting is mainly just about Clear and Calm thinking..
pdvfirstblog.blogspot.com/2025/10/simp...
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...
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
October 14, 2025 at 10:30 PM
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...
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
Let’s put some old SQL myths to the test together!
#Oracle #SQL #Optimizer #Accenture #OracleAce
September 29, 2025 at 11:48 AM
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
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
May 30, 2025 at 1:05 PM
How do I get the test data these days? My #Accenture colleague @cgohmannde.bsky.social explains. #makeit2025
May 30, 2025 at 11:54 AM
Reposted by Andrej Pashchenko
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
May 29, 2025 at 4:16 PM
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
May 29, 2025 at 1:20 PM
How can we help the Oracle optimizer to do better with function calls? @danischnider.bsky.social explains. #makeit2025
Reposted by Andrej Pashchenko
After the keynote at #MakeITConf, my Accenture colleague @andrejsql.bsky.social shared some interesting insights of table merging.
@oracleace.bsky.social
@oracleace.bsky.social
May 29, 2025 at 9:10 AM
After the keynote at #MakeITConf, my Accenture colleague @andrejsql.bsky.social shared some interesting insights of table merging.
@oracleace.bsky.social
@oracleace.bsky.social
Reposted by Andrej Pashchenko
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 talking about table merging at #MakeIT2025
May 29, 2025 at 8:08 AM
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 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...
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
May 8, 2025 at 6:14 AM
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...
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...
#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
April 22, 2025 at 7:13 AM
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...
#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...
catalog-education.oracle.com/pls/certview...
Oracle AI Vector Search Certified Professional
he Oracle AI Vector Search Professional Certification is designed for Oracle DBAs, AI engineers, and cloud developers to unlock the potential of Oracle Database 23ai to build AI-driven applications. T...
catalog-education.oracle.com
March 7, 2025 at 4:46 PM
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...
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...
#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
January 6, 2025 at 7:03 AM
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...
#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 😃
December 3, 2024 at 10:23 AM
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...
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...
November 25, 2024 at 3:08 PM
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...
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
November 20, 2024 at 12:18 PM
@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.
First session at #DOAG2024 by @andrejsql.bsky.social about SQL Macros. Lot of examples and ideas after a short introduction.
November 19, 2024 at 10:16 AM
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
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
November 18, 2024 at 2:32 PM
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
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