I started to notice this in a big way at my last job which I started in 2013. We were a rails shop and by about 2016 I was noticing most new hires would have no idea how to write a SQL query.

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cultofmetatron 6 days ago | parent [-]

> most new hires would have no idea how to write a SQL query.

probably why people think rails is slow. our integration partners and our customers are constantly amazed by how fast and efficient our system is. The secret is I know how to write a damn query. you can push a lot of logic that would otherwise be done in the api layer into a query. if done properly with the right indexes, its going to be WAY faster than pulling the data into the api server and doing clumsy data transformations there.

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strtok 6 days ago | parent | next [-]

1000%. It’s all about limiting those round trips to the database…

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mirkodrummer 6 days ago | parent | prev [-]

You actually confirmed that rails is slow if the optimization is on the database server and doing data mangling in ruby is less efficient

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runako 6 days ago | parent | next [-]

Constructively, I would suggest some areas for study:

- relative speeds of programming languages (https://github.com/niklas-heer/speed-comparison)

- database indexing (https://stackoverflow.com/questions/1108/how-does-database-i...)

- numbers everyone should know (https://news.ycombinator.com/item?id=39658138)

And note that databases are generally written in C.

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mirkodrummer 6 days ago | parent [-]

Constructively, I just wanted to say that you can't claim that something is fast if speed is thanks to something else. OP said people thinks rails is slow but if you have a fast query it's a solved problem. Even python would be fast in this instance with an optimized query

	▲	cultofmetatron 6 days ago \| parent [-]
		> Even python would be fast in this instance with an optimized query I wasn't trying to argue that ruby is slow (it objectively is). I was arguing that its slowness is irrelevant for most webapps because you should be offloading most of the load to your database with efficient queries.

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closeparen 6 days ago | parent | prev | next [-]

Unless the database is in your process's address space (SQLite, Datomic, etc) your first problem is going to be shipping the data from the database server to the application process.

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richwater 6 days ago | parent | prev [-]

You've correctly identified that filtering a list is slower than looking up from an index. Congratulations.

	▲	mirkodrummer 6 days ago \| parent [-]
		Thank you, let me give you the eli5: I just wanted to say that you can't claim that something is fast if speed is thanks to something else