Database Indexing Explained (with PostgreSQL)

how to performance tune? explain analyze select ...(performance report)
table vs index(two different data structures on the disk)
slow vs fast

index scan
no index scan
like

That plan analyze of pg is disappointing unhelpful

thank you!

great video

Best introduction video on indexing I've seen. I feel like I finally understood the concept. Thabks. The "like" expression was a great addition.

Thank you for clarifying concept database indexing.
I appreciate your insights, but I'm still a bit puzzled about a few things.

While I understand that traditional relational databases have robust implementations of indexing, I'm curious to know why one might opt for search engines, like Elasticsearch, over them. Specifically, how does Elasticsearch indexing differ from that of relational databases?

Moreover, are there specific challenges or limitations associated with relational database indexing that Elasticsearch indexing can address more effectively?

I'd greatly appreciate any further insights you can provide on this topic.

Thank you in advance for your time and assistance.

Thank you for this informative video❤. You're worth subscribing❤

Like %za% is slow,
however I feel,
Like za% would benefit from index

Great explanation. Thanks

Will putting an index on a View help?

Great content!!! Thanks!

Would be nice to know if the index helps in case the expression is "like 'Za%'". Intuitively it should be able to the rows starting with Za and take advantage of the index, what do you think?

How to make queries containing like conditions faster?

Which one is better, having different indexes for different columns or having one index containing multiple columns and can you give examples of in which case which option to go for?

awesome

Wooooooooowwwwww <3

Amazing 🤍🇮🇶

Thanks. It is a really amazing lesson I have learnt from this discussion.

Thanks you so much for such a details explanation

this was a nice demonstration of indexing, thanks!

@Hussien Naseer can you do same for mongodb and lookups

You are a gift from God for us backend developers.

What is the best way to use instead of Like query if some similar query needs to be implemented.
Use fullTextSearch or elasticSearch or any other things or is there a way?

what a low effort video. went through the whole "what is an index" section all while showing a black terminal screen

This was simply wow 👏🏻

in this quick video I jumped into Database Flow world!!! really appreciate your work, bro

Awesome explanation

Thanks for your time! Great intro to indexes

Ok so is there a smarter way to do the like query?

Nasser, Your videos are really informative and it helps me picture the topic . More power to you , god bless

Video is good but I was also expecting clustered index and non clustered index

Why did '%Zs%' execute so much faster than 'Zs'? Because of cache again?

I wonder how BTree works for string type

I have learned in this video more than I learned in a complete university semester

الله يحفظك ❣

Just perfect! Thank ya!

Thank's man, very useful info)

even with indexong a table in our production takes more than 2 minutes to run... 😂🥱

Jajksi <3 hahahha tnx for the video man

I ran the same command "explain analyze select id from country where id = 8" on a table named country which I have but it was showing "Heap Fetches: 1"
I am on postres version 9.3
Any idea why is that?

Love it, thank you :)

Why the "like" command took less time than the actual "select" command with no "like"? Was that also cached?
@HusseinNasser Just needed some explanation over that !?

good info... thanks...

very interested in how:
- a dattabase decide in what page save a record
- how variable size rows are stored (a page can have 1 row... or 10 rows)
- what if a record is bigger than the page size?

keep up----