How do Databases Work? | System Design

[@tonynguyen-mq3tb]

🎯 Key points for quick navigation: 00:00 *📚 What is a database and how queries work?* - Database takes in SQL queries to retrieve data. - SQL is declarative, focusing on what data is needed not how to get it. - Internal complexities of a database translate declarative queries into execution steps. 02:09 *🧠 Process of executing a query in a database* - Database query process involves parsing, query planning, and execution. - Parser translates SQL query into a data structure for the database to use. - Query planner optimizes query execution and evaluates different plans based on database characteristics. 03:32 *🔍 Role of parser in database query execution* - Parser converts raw SQL text into a parse tree for easier database evaluation. - Parse tree organizes query components like select, from, and where clauses for database use. - Use of parse tree allows the database to recursively evaluate query components. 08:12 *⚙️ Query planner in optimizing database query execution* - Query planner considers table statistics, cost constants, and available indexes for query optimization. - It generates multiple plans, evaluates costs for each, and outputs the most efficient plan. - Optimizing query planning leads to faster and more efficient database query execution. Made with HARPA AI

[@mohitnagpal]

Your videos are very helpful and to the point.

[@interviewpen]

Glad you like it :)

[@mineline5620]

dude this laser pointer is giving me flashbacks from school lmao

[@Travala]

Thanks, I really like the videos! But (in my personal opinion) it would be much easier to perceive information if you took some pauses when you speak. Otherwise, videos are really helpful! And one of the topics I would love to know more about is how systems like Apache Spark or Hadoop work internally, what are the specific use cases and etc. Thanks again!

[@interviewpen]

Ok, thanks for the feedback. We do have multiple videos on Spark/Hadoop in our full course on interviewpen.com :)

[@kspv2806]

Awesome thanks a lot

[@interviewpen]

Thanks for watching!

[@webcorejuan]

Awesome, which software do you use?

[@interviewpen]

We use GoodNotes on an iPad. Thanks for watching!

[@NimaqAlizadeh]

Nice🎉

[@interviewpen]

Thanks for watching!

[@congminhluu5068]

I'm dumb so any help would be appreciated. Why are hash join on 100 rows tables faster than hash join on 10 rows tables ?

[@interviewpen]

It isn’t-we prefer the plan that filters the tables first, since fewer rows have to be joined that way. Thanks!

[@ak-gi3eu]

how algorithms works video plz

[@infinitibucket]

First viewer. Hurrah

[@interviewpen]

Nice 😛

[@dami970]

Seems like I came early

[@interviewpen]

🫡

[@Zmey5656]

Thank you a lot for your video. Maybe next time tell us about the pros and cons of SQL? For example, that is invented in the 80s and that it is ineffective when working with a large amount of data?

[@interviewpen]

Absolutely--we have a full video about different data models and storage formats (like NoSQL) on interviewpen.com :)

[@saramshshrestha7641]

CS degree help me understand it pretty clearly. 😅