undefined | Better HN

0 pointsiLoveOncall28d ago0 comments

Why are you comparing PostgreSQL to an in-memory SQLite instead of a file-based one? Wow, memory is faster than disk, who would have thought?

0 comments

eurleif28d ago

Because it doesn't make a difference, because `SELECT 1` doesn't need to touch the database:

    Running 100,000 `SELECT 1` queries:
    PostgreSQL (localhost): 2.71 seconds
    SQLite (in-memory): 0.07 seconds
    SQLite (tempfile): 0.07 seconds

(https://gist.github.com/leifkb/d8778422d450d9a3f103ed43258cc...)

oldsecondhand28d ago

Why are you doing meaningless microbenchmarks?

saturn_vk28d ago

Are you claiming that this does not show the speed difference between socket vs in process communication?

locknitpicker28d ago

> Because it doesn't make a difference, because `SELECT 1` doesn't need to touch the database:

I hope you understand that your claim boils down to stating that SQLite is faster at doing nothing at all, which is a silly case to make.

eurleif28d ago

The original claim being discussed is about the overhead of an in-process database vs. a database server in a separate process, not about whether SQLite or PostgreSQL have a faster database engine.

j4528d ago

Queries for small SaaS are usually in the thousands of records, if not hundreds.

nchmy28d ago

How about pg on Unix socket?

eurleif28d ago

    Running 100,000 `SELECT 1` queries:
    PostgreSQL (localhost): 2.84 seconds
    PostgreSQL (Unix socket): 1.93 seconds
    SQLite (in-memory): 0.07 seconds
    SQLite (tempfile): 0.06 seconds

(https://gist.github.com/leifkb/b940b8cdd8e0432cc58670bbc0c33...)

onraglanroad27d ago

You appear to have benchmarked how quickly Python can access memory vs how quickly Python can open and close a socket. I'm not sure the DBs were required in any way.

nchmy28d ago

seems about right

j / k navigate · click thread line to collapse

0 comments

eurleif28d ago

Because it doesn't make a difference, because `SELECT 1` doesn't need to touch the database:

    Running 100,000 `SELECT 1` queries:
    PostgreSQL (localhost): 2.71 seconds
    SQLite (in-memory): 0.07 seconds
    SQLite (tempfile): 0.07 seconds

(https://gist.github.com/leifkb/d8778422d450d9a3f103ed43258cc...)

oldsecondhand28d ago

Why are you doing meaningless microbenchmarks?

saturn_vk28d ago

Are you claiming that this does not show the speed difference between socket vs in process communication?

locknitpicker28d ago

> Because it doesn't make a difference, because `SELECT 1` doesn't need to touch the database:

I hope you understand that your claim boils down to stating that SQLite is faster at doing nothing at all, which is a silly case to make.

eurleif28d ago

The original claim being discussed is about the overhead of an in-process database vs. a database server in a separate process, not about whether SQLite or PostgreSQL have a faster database engine.

j4528d ago

Queries for small SaaS are usually in the thousands of records, if not hundreds.

nchmy28d ago

How about pg on Unix socket?

eurleif28d ago

    Running 100,000 `SELECT 1` queries:
    PostgreSQL (localhost): 2.84 seconds
    PostgreSQL (Unix socket): 1.93 seconds
    SQLite (in-memory): 0.07 seconds
    SQLite (tempfile): 0.06 seconds

(https://gist.github.com/leifkb/b940b8cdd8e0432cc58670bbc0c33...)

onraglanroad27d ago

You appear to have benchmarked how quickly Python can access memory vs how quickly Python can open and close a socket. I'm not sure the DBs were required in any way.

nchmy28d ago

seems about right

j / k navigate · click thread line to collapse