Tanel Poder
@tanelpoder.com
Creator of https://0x.tools, also a long-time computer performance geek. Perf & troubleshooting blog: tanelpoder.com. All onions are mine.
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Tanel Poder
@tanelpoder.com
· 12d
Back in the the day we did something similar (for Oracle execution plans), called PlanViz:
tanelpoder.com/posts/sql-pl...
tanelpoder.com/posts/sql-pl...
Reposted by Tanel Poder
Vinicius Grippa has created a cool implementation of SQL Flamegraphs for MySQL: MyFlames.
GitHub repo here, look into demos/mysql-*.svg files for more examples:
github.com/vgrippa/myfl...
GitHub repo here, look into demos/mysql-*.svg files for more examples:
github.com/vgrippa/myfl...
February 2, 2026 at 5:47 PM
Vinicius Grippa has created a cool implementation of SQL Flamegraphs for MySQL: MyFlames.
GitHub repo here, look into demos/mysql-*.svg files for more examples:
github.com/vgrippa/myfl...
GitHub repo here, look into demos/mysql-*.svg files for more examples:
github.com/vgrippa/myfl...
Vinicius Grippa has created a cool implementation of SQL Flamegraphs for MySQL: MyFlames.
GitHub repo here, look into demos/mysql-*.svg files for more examples:
github.com/vgrippa/myfl...
GitHub repo here, look into demos/mysql-*.svg files for more examples:
github.com/vgrippa/myfl...
February 2, 2026 at 5:47 PM
Vinicius Grippa has created a cool implementation of SQL Flamegraphs for MySQL: MyFlames.
GitHub repo here, look into demos/mysql-*.svg files for more examples:
github.com/vgrippa/myfl...
GitHub repo here, look into demos/mysql-*.svg files for more examples:
github.com/vgrippa/myfl...
Reposted by Tanel Poder
A free SQL explain plan visualizer tool by @datadoghq
Currently for PostgreSQL, MySQL, MSSQL and MongoDB
explain.datadoghq.com
Currently for PostgreSQL, MySQL, MSSQL and MongoDB
explain.datadoghq.com
January 28, 2026 at 11:18 PM
A free SQL explain plan visualizer tool by @datadoghq
Currently for PostgreSQL, MySQL, MSSQL and MongoDB
explain.datadoghq.com
Currently for PostgreSQL, MySQL, MSSQL and MongoDB
explain.datadoghq.com
If you clone the same (cat) photo into 360 versions, each rotated by one more degree, then put all these versions through a ViT embedding model, should the resulting cat-vectors look at least somewhat similar?
I used a heatmap to answer this question!
tanelpoder.com/catvector/
I used a heatmap to answer this question!
tanelpoder.com/catvector/
January 28, 2026 at 11:56 PM
If you clone the same (cat) photo into 360 versions, each rotated by one more degree, then put all these versions through a ViT embedding model, should the resulting cat-vectors look at least somewhat similar?
I used a heatmap to answer this question!
tanelpoder.com/catvector/
I used a heatmap to answer this question!
tanelpoder.com/catvector/
Reposted by Tanel Poder
The view GV$SYSMETRIC_HISTORY in Oracle AI Database shows all the database metrics available
This can be useful to help troubleshoot performance issues
@tanelpoder.com has built scripts to display these with 1-minute granularity in a tabular way
This can be useful to help troubleshoot performance issues
@tanelpoder.com has built scripts to display these with 1-minute granularity in a tabular way
New scripts: vstat.sql & dstat.sql for showing Oracle Sysmetric history with 1-minute granularity - Tanel Poder Blog
Here are two scripts for showing GV$SYSMETRIC_HISTORY contents in a simple tabular way: vstat.sql - show up to one hour of current history at 1-minute granularity from memory awr/dstat.sql - show…
buff.ly
January 28, 2026 at 12:01 PM
The view GV$SYSMETRIC_HISTORY in Oracle AI Database shows all the database metrics available
This can be useful to help troubleshoot performance issues
@tanelpoder.com has built scripts to display these with 1-minute granularity in a tabular way
This can be useful to help troubleshoot performance issues
@tanelpoder.com has built scripts to display these with 1-minute granularity in a tabular way
A free SQL explain plan visualizer tool by @datadoghq
Currently for PostgreSQL, MySQL, MSSQL and MongoDB
explain.datadoghq.com
Currently for PostgreSQL, MySQL, MSSQL and MongoDB
explain.datadoghq.com
January 28, 2026 at 11:18 PM
A free SQL explain plan visualizer tool by @datadoghq
Currently for PostgreSQL, MySQL, MSSQL and MongoDB
explain.datadoghq.com
Currently for PostgreSQL, MySQL, MSSQL and MongoDB
explain.datadoghq.com
Reposted by Tanel Poder
modern-sql.com now covers DuckDB.
Modern SQL: A lot has changed since SQL-92
SQL has evolved. Beyond the relational model. Discover it now.
modern-sql.com
November 28, 2025 at 1:24 PM
modern-sql.com now covers DuckDB.
Reposted by Tanel Poder
Happy Thanksgiving! Need a pod while washing dishes? New Oxide and Friends examines a bug introduced over 18 years ago. Performance is great but not—it turns out—without correctness oxide-and-friends.transistor.fm/episodes/gro...
Oxide and Friends | Grown-up ZFS Data Corruption Bug
Hey hey! We recently tripped over a ZFS data corruption bug–introduced over 18 years ago! Bryan and Adam discuss with members of the Oxide team as well as Matt Ahrens, the co-inventor of ZFS.In add...
oxide-and-friends.transistor.fm
November 27, 2025 at 9:43 PM
Happy Thanksgiving! Need a pod while washing dishes? New Oxide and Friends examines a bug introduced over 18 years ago. Performance is great but not—it turns out—without correctness oxide-and-friends.transistor.fm/episodes/gro...
(3 days left until the end of Black Friday Sale of my online training courses!)
Also, an old post for Oracle nerds:
"Oracle Shared Pool Internals: List Chunk Position in the LRU List"
tanelpoder.com/posts/oracle...
Also, an old post for Oracle nerds:
"Oracle Shared Pool Internals: List Chunk Position in the LRU List"
tanelpoder.com/posts/oracle...
November 28, 2025 at 7:14 PM
(3 days left until the end of Black Friday Sale of my online training courses!)
Also, an old post for Oracle nerds:
"Oracle Shared Pool Internals: List Chunk Position in the LRU List"
tanelpoder.com/posts/oracle...
Also, an old post for Oracle nerds:
"Oracle Shared Pool Internals: List Chunk Position in the LRU List"
tanelpoder.com/posts/oracle...
Reposted by Tanel Poder
When tuning #SQL, focus on the estimates for how many rows each operation will return
If these are off by an order of magnitude or more, there's a good chance a different plan is faster
@tanelpoder.com has built scripts to show misestimates in Oracle plans
If these are off by an order of magnitude or more, there's a good chance a different plan is faster
@tanelpoder.com has built scripts to show misestimates in Oracle plans
xb.sql and xbi.sql - Explain Oracle Execution Plans Better! (Part 3 - Cardinality Misestimates) - Tanel Poder Consulting
Here’s part 3 of my xb.sql & xbi.sql article series that I started writing back in 2019 :-) Part 1 - Show and format execution plans by querying V$SQL_PLAN data directly Part 2 - Show plan line level…
buff.ly
November 26, 2025 at 12:01 PM
When tuning #SQL, focus on the estimates for how many rows each operation will return
If these are off by an order of magnitude or more, there's a good chance a different plan is faster
@tanelpoder.com has built scripts to show misestimates in Oracle plans
If these are off by an order of magnitude or more, there's a good chance a different plan is faster
@tanelpoder.com has built scripts to show misestimates in Oracle plans
One week left till the end of the Black Friday sale of my self-paced video learning courses! 🤓
I just extended the Black Friday sale to the whole month of November!
All my existing full-week flagship courses are heavily discounted for the entire month, and more content coming soon!
tanelpoder.com/posts/black-...
All my existing full-week flagship courses are heavily discounted for the entire month, and more content coming soon!
tanelpoder.com/posts/black-...
November 24, 2025 at 3:48 AM
One week left till the end of the Black Friday sale of my self-paced video learning courses! 🤓
Reposted by Tanel Poder
cool job at a very special computer company
- write TypeScript and Rust
- everyone makes $235k
- fully remote
- everything is open source
- write TypeScript and Rust
- everyone makes $235k
- fully remote
- everything is open source
Product Engineer / Oxide
oxide.computer
November 19, 2025 at 6:33 PM
cool job at a very special computer company
- write TypeScript and Rust
- everyone makes $235k
- fully remote
- everything is open source
- write TypeScript and Rust
- everyone makes $235k
- fully remote
- everything is open source
Reposted by Tanel Poder
Biggest takeaway from KubeCon: People want Neki badly.
We're building the solution for scaling and managing huge Postgres databases.
More to come, but in the meantime: neki.dev
We're building the solution for scaling and managing huge Postgres databases.
More to come, but in the meantime: neki.dev
Neki - Sign Up
Join Neki and stay updated with our latest news and updates.
neki.dev
November 14, 2025 at 5:40 PM
Biggest takeaway from KubeCon: People want Neki badly.
We're building the solution for scaling and managing huge Postgres databases.
More to come, but in the meantime: neki.dev
We're building the solution for scaling and managing huge Postgres databases.
More to come, but in the meantime: neki.dev
Reposted by Tanel Poder
Turns out you can communicate across containers via 63-bits of available space in a shared lock you acquire on /proc/self/ns/time that all processes have access to.
No networking required. The post has a demo of a chat app communicating across unprivileged containers.
h4x0r.org/funreliable/
No networking required. The post has a demo of a chat app communicating across unprivileged containers.
h4x0r.org/funreliable/
November 12, 2025 at 2:35 PM
Turns out you can communicate across containers via 63-bits of available space in a shared lock you acquire on /proc/self/ns/time that all processes have access to.
No networking required. The post has a demo of a chat app communicating across unprivileged containers.
h4x0r.org/funreliable/
No networking required. The post has a demo of a chat app communicating across unprivileged containers.
h4x0r.org/funreliable/
Reposted by Tanel Poder
Added a blog update about the V$PROCESS_MEMORY_DETAIL auto-population for processes with PGA growth to over 500MB. Enabled in Oracle 19.18+, so no "oradebug dump pga_get_detail" needed, just query the V$ views for a detailed "heapdump":
tanelpoder.com/2014/03/26/o...
tanelpoder.com/2014/03/26/o...
November 10, 2025 at 6:29 AM
Added a blog update about the V$PROCESS_MEMORY_DETAIL auto-population for processes with PGA growth to over 500MB. Enabled in Oracle 19.18+, so no "oradebug dump pga_get_detail" needed, just query the V$ views for a detailed "heapdump":
tanelpoder.com/2014/03/26/o...
tanelpoder.com/2014/03/26/o...
Reposted by Tanel Poder
New scripts: vstat.sql & dstat.sql for showing Oracle Sysmetric history with 1-minute granularity (both from AWR and regular V$ views)
tanelpoder.com/posts/oracle...
tanelpoder.com/posts/oracle...
November 10, 2025 at 5:52 AM
New scripts: vstat.sql & dstat.sql for showing Oracle Sysmetric history with 1-minute granularity (both from AWR and regular V$ views)
tanelpoder.com/posts/oracle...
tanelpoder.com/posts/oracle...
Added a blog update about the V$PROCESS_MEMORY_DETAIL auto-population for processes with PGA growth to over 500MB. Enabled in Oracle 19.18+, so no "oradebug dump pga_get_detail" needed, just query the V$ views for a detailed "heapdump":
tanelpoder.com/2014/03/26/o...
tanelpoder.com/2014/03/26/o...
November 10, 2025 at 6:29 AM
Added a blog update about the V$PROCESS_MEMORY_DETAIL auto-population for processes with PGA growth to over 500MB. Enabled in Oracle 19.18+, so no "oradebug dump pga_get_detail" needed, just query the V$ views for a detailed "heapdump":
tanelpoder.com/2014/03/26/o...
tanelpoder.com/2014/03/26/o...
New scripts: vstat.sql & dstat.sql for showing Oracle Sysmetric history with 1-minute granularity (both from AWR and regular V$ views)
tanelpoder.com/posts/oracle...
tanelpoder.com/posts/oracle...
November 10, 2025 at 5:52 AM
New scripts: vstat.sql & dstat.sql for showing Oracle Sysmetric history with 1-minute granularity (both from AWR and regular V$ views)
tanelpoder.com/posts/oracle...
tanelpoder.com/posts/oracle...
Reposted by Tanel Poder
FreeSQL.com now supports SQLNet connectivity for your free schema on both our 19c and 26ai database platforms.
FreeSQL.com
November 6, 2025 at 10:42 PM
FreeSQL.com now supports SQLNet connectivity for your free schema on both our 19c and 26ai database platforms.
Reposted by Tanel Poder
A bunch of folks at Oxide uncovered a tricky deadlock associated with async Rust (yes, another!), so--of [email protected] and I got the crew together to discuss. If you're writing async Rust, you'll want to know how to avoid and diagnose "Futurelock"
Oxide and Friends 11/3/2025 -- Futurelock
YouTube video by Oxide Computer Company
www.youtube.com
November 6, 2025 at 3:20 PM
A bunch of folks at Oxide uncovered a tricky deadlock associated with async Rust (yes, another!), so--of [email protected] and I got the crew together to discuss. If you're writing async Rust, you'll want to know how to avoid and diagnose "Futurelock"
Reposted by Tanel Poder
This post is awesome eavan.blog/posts/implem...
Please Implement This Simple SLO
eavan.blog
November 6, 2025 at 12:31 AM
This post is awesome eavan.blog/posts/implem...
Reposted by Tanel Poder
In concept I’m a huge fan of porting infrastructural code to Rust/memory safe languages, but shipping broken code — especially code that causes silent data loss — doesn’t help that cause.
`dd` incorrectly counts partial reads toward `count` limit, causing data loss in pipelines · Issue #9119 · uutils/coreutils
Summary uutils dd has a critical bug where partial reads from pipes are counted toward the count=N limit, causing premature termination and significant data loss. GNU dd correctly only counts full ...
github.com
November 5, 2025 at 11:28 PM
In concept I’m a huge fan of porting infrastructural code to Rust/memory safe languages, but shipping broken code — especially code that causes silent data loss — doesn’t help that cause.
Reposted by Tanel Poder
I just extended the Black Friday sale to the whole month of November!
All my existing full-week flagship courses are heavily discounted for the entire month, and more content coming soon!
tanelpoder.com/posts/black-...
All my existing full-week flagship courses are heavily discounted for the entire month, and more content coming soon!
tanelpoder.com/posts/black-...
November 2, 2025 at 9:45 PM
I just extended the Black Friday sale to the whole month of November!
All my existing full-week flagship courses are heavily discounted for the entire month, and more content coming soon!
tanelpoder.com/posts/black-...
All my existing full-week flagship courses are heavily discounted for the entire month, and more content coming soon!
tanelpoder.com/posts/black-...
Reposted by Tanel Poder
New blog: xb.sql and xbi.sql - Explain Oracle Execution Plans Better! (Part 3 - Cardinality Misestimates)
tanelpoder.com/posts/xb-sql...
tanelpoder.com/posts/xb-sql...
November 3, 2025 at 7:48 AM
New blog: xb.sql and xbi.sql - Explain Oracle Execution Plans Better! (Part 3 - Cardinality Misestimates)
tanelpoder.com/posts/xb-sql...
tanelpoder.com/posts/xb-sql...
New blog: xb.sql and xbi.sql - Explain Oracle Execution Plans Better! (Part 3 - Cardinality Misestimates)
tanelpoder.com/posts/xb-sql...
tanelpoder.com/posts/xb-sql...
November 3, 2025 at 7:48 AM
New blog: xb.sql and xbi.sql - Explain Oracle Execution Plans Better! (Part 3 - Cardinality Misestimates)
tanelpoder.com/posts/xb-sql...
tanelpoder.com/posts/xb-sql...