Jonathan Lewis

50 years using computers, 40 years freelancing, 35 years dealing with Oracle design and performance issues; mostly retired.
Now tweeting at

[Jonathan Lewis @JLOracle]

The demon subdomain, including my old website disappeared a while ago, but there is a copy from December 2018 on the Wayback machine starting at:

https://t.co/D9qBXqwJTu

[Oxford Mathematics @OxUniMaths]

No words required.

[Jonathan Lewis @JLOracle]

@tmmdv But some people prefer to travel by train ;)

[Jonathan Lewis @JLOracle]

@connor_mc_d Are booleans in the database really useful? 😉

[Jonathan Lewis @JLOracle]

I'm on the agenda for the #ukoug conference 2025.
9:00 a.m. on Monday morning (I tell myself that that's to encourage people to be on-site early enough to attend the opening keynote afterwards)

https://t.co/oB7MbPCByr

[Jonathan Lewis @JLOracle]

@orcldoug I'm sure that wasn't the way that Pavlov set up the experiment.

[Stephen John Lyons @sjlyons50]

@NSFVoyager2 @xipteras Another view of your launch: https://t.co/cgVQJslcf9

[NASA @NASA]

We are saddened by the passing of Jim Lovell, commander of Apollo 13 and a four-time spaceflight veteran.

Lovell's life and work inspired millions. His courage under pressure helped forge our path to the Moon and beyond—a journey that continues today. https://t.co/AjT8qmxsZI

[Jonathan Lewis @JLOracle]

@oraclebase @pdevisser It's a book where you don't know whether the next page is going to make you laugh, cry, wince, shake your head at the utter stupidity of people, or rage against the treatment of NHS staff by successive governments.

[Jonathan Lewis @JLOracle]

@oraclebase @pdevisser Suggested reading: "This is going to hurt" by Adam Kay.

[Jonathan Lewis @JLOracle]

Two months since the last blog note, I hope it's worth the wait:
https://t.co/wNbwd78tOP

[Tanel Poder 🇺🇦 @TanelPoder]

@lemire I think the more practical question (for now) is if a senior dev would end up producing junior level code when using AI agents?

(... having distractions and deadlines, etc...)

[ORA-600 @POUG_ORG]

More than 3 months to #POUG2025 and we have 30 tickets left. Do you really want to miss over 40 tech sessions (no marketing! no sales pitches!) & opportunity to meet #Oracle stars like @connor_mc_d @JLOracle or @KerryOracleGuy ?
Buy now or cry later:
https://t.co/fSftpgkmlD

[Jonathan Lewis @JLOracle]

I've just come across a blog note I wrote a few years ago about unexpected (and unreliable) results from v$undostat when it reports the "maxquerylen / id"; it's probably worth knowing about it:
https://t.co/eRfIbrkZjq

[Brian Fitzgerald @ExaGridDba]

@chris_skyflier @martinberx @OracleSK @JLOracle The days of running oradebug without restriction are numbered!
https://t.co/Jfc4YBOcAb

[Jonathan Lewis @JLOracle]

@DineshParva Sorry, no. The optimizer was changing far too quickly for me to do all the testing and modelling to keep up to date with the possibilities.

[Jonathan Lewis @JLOracle]

I'll be speaking at #POUG2025 (Sept 5th/6th). https://t.co/h987AYVvTB

The abstract for my session is the sole entry under the "Public Appearances" page on my blog:
https://t.co/HG00zlwMAX...

[Oxford Mathematics @OxUniMaths]

The old mathematical ones are the best.

Maybe jokes are like mathematics. You either get them or you don't. But if you need a clue for Vishal's joke, this might help:

https://t.co/bXXdlAUn1S

[Connor on SQL and Database @connor_mc_d]

Calling out delusional developers...

https://t.co/UBLFtSfO2F

[Morten Braten @mortenbraten]

@StewAshton @FranckPachot @gwenshap @connor_mc_d If your developers are talking about the database as «the Persistence Layer», you are in trouble 🥸

[Tim Hall ∞🐵+∞⌨️ @oraclebase]

"If you trust in yourself and believe in your dreams and follow your star you'll still get beaten by people who spent their time working hard and learning things and weren't so lazy."

Miss Tick (The Wee Free Men, Terry Pratchett)