I installed macOS and iOS 26 public beta today. The main attraction in this update is the design change called Liquid Glass...
macOS and iOS 26 public beta impressions
Useful PL/SQL queries
In this post, I’m sharing some handy PL/SQL queries that help with monitoring and maintaining Oracle databases...
NOT IN vs NOT EXISTS in PL/SQL
SELECT *
FROM TABLE1
WHERE ID NOT IN (
SELECT ID
FROM TABLE2
)
When I ran the above query I know the condition will give me the results, because the data exists in the TABLE1 which is not in TABLE2. But I didn’t go any results. I got surprised. After I a while I found out the issue.
So the reason is that ID column in the TABLE2 have null values. If any value of ID in the subquery is NULL, then the entire NOT IN clause fails to match anything. This is standard SQL behavior because NULL makes the whole comparison unknown.
Solution:
- You can use
NOT NULLcondition in the sub-query as below:
SELECT *
FROM TABLE1
WHERE ID NOT IN (
SELECT ID
FROM TABLE2
WHERE ID IS NOT NULL
)
- Use
NOT EXISTS:
SELECT *
FROM TABLE1 T1
WHERE NOT EXISTS (
SELECT 1
FROM TABLE2 T2
WHERE T1.ID = T2.ID
)
The NOT EXISTS will automatically handle null values and safer to use.
References
Difference between React and ReactDOM
React is a JavaScript library for building user interfaces. ReactDOM, on the other hand, is a library that provides an interface between React and the DOM...
Unhang Windows PC
I often found that Ctrl+Alt+Delete unhangs the Windows PC. I googled why?
The nutshell answer is : Ctrl+Alt+Delete is a secure attention sequence (SAS) triggers a system interrupt, effectively forcing the computer to respond. This is directly handled by the Windows operating system kernel. That means it can bypass most of the stuff that’s currently running (including frozen apps or even some parts of the graphical interface).
Cool to know this.
Featured posts in Hugo
Today, I updated the about page to display featured blog sections dynamically using front matter tags. This replaces the previous hardcoded method for a more flexible setup.
Diffdiff and Emoji Kitchen
I just found two tools:
- diffdiff is a fast, private way to compare two pieces of text, created by Joe Kaptur. It’s interface is so clean and good.
- An impressive emoji-mixing site called Emoji Kitchen, created by Xavier Salazar.

Thunder and Unicorn mixed by Emoji Kitchen
Google AI Overview
I don’t search for things as much as I used to. These days, I just go straight to ChatGPT. I don’t feel like Googling and clicking through multiple pages to find the best answer. I ask ChatGPT, and most of the time, the results are satisfying.
I’ve heard that traditional Google searches are declining. But now, they’ve introduced AI Overviews at the top of their results. I think it’s a good idea—because we get a quick summary of what we’re looking for, along with links to other websites. Yes, I think it’s a good move.

Custom folder Icons with Material Icon Theme
Install Material Icon Theme
In settings.json:
"material-icon-theme.folders.associations": {
"folder-name": "Home"
}
folder-name is the folder name and Home is the icon.
You can find the files and folders icons in here.