Optimize Your SQL Queries | Postgres Edition

Easy way you can analyze and optimize your SQL queries to get the best performance out of them.
Reference: thoughtbot.com/blog/reading-a...
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0:00 Agenda
01:15 Difference between EXPLAIN & EXPLAIN ANALYZE
02:35 How count of returned rows affect performance
04:15 How to monitor index usage
10:30 Aggregation queries using indexes
13:37 Information about JOIN algorithms
18:15 ORDER BY using Index forward and backward
20:56 How to read query plans
22:10 Outro
#database #mysql #postgres

[@xanthus1]

Just wanted to say thanks for this video! This was a great step by step breakdown and analysis.

[@irtizahafiz]

Thank you for taking the time to leave a comment. Glad you found it useful.

[@DanielSposito]

All of your videos are excellent. Thank you for the clear explanations and detailed examples. I hope you continue to create more videos for your channel!

[@irtizahafiz]

Glad you found it helpful! Cheers!

[@luanlucas8605]

Hi. Found your channel today and subscribed. Pretty good content here. Keep it up :D

[@irtizahafiz]

Welcome aboard!

[@user-ct2mp1xt4f]

thank you it was very clear

[@robertczaja176]

great video thanks a lot!

[@irtizahafiz]

Glad you liked it!

[@Rashidulhasan777]

Near 17:40, I think the volume table doesn’t have only one row. I think it decided to sequentially scan the volume table for each volume.volume_id will then match book.volume_id with each volume.volume_id. And for matching purposes, it is doing index scan as there is an index for book.volume_id. Sorry, I might be wrong. I didn’t understand how DBMS decided which table it will do the sequential scan first? Thanks for your video!

[@irtizahafiz]

Hi! Thank you for explaining. The link I have in the description should give you a better understanding of how to read these query plans. I was just trying to explain the tool, rather than go into the details of how to read them.