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0 pointscrazygringo1y ago0 comments

Perhaps I wasn't clear enough in my comment. When I said "database latency is generally miniscule compared to internet round-trip latency", I meant between the user and the website. Because they're often thousands of miles away, there are network buffers, etc.

But no, a local network hop doesn't introduce "orders of magnitude" more latency. The article itself describes how it is only 5x slower within a datacenter for the roundtrip part -- not 100x or 1,000x as you are claiming. But even that is generally significantly less than the time it takes the database to actually execute the query -- so maybe you see a 1% or 5% speedup of your query. It's just not a major factor, since queries are generally so fast anyways.

The kind of database latency that you seem to be trying to optimize for is a classic example of premature optimization. In the context of a web application, you're shaving microseconds for a page load time that is probably measured in hundreds of milliseconds for the user.

> I don't get to decide this. The business does.

You have enough power to design the entire database architecture, but you can't write and execute queries more efficiently, following best practices?

0 comments

3921y ago

Sqlite can be run in process. Latency and bandwidth can be made 10x worst by process context switching alone. Plus being able to get away with n+1s could save a lot of dev time depending on the crew, before Claude (tho the dev still needs to learn that the speed problem is due to this and refactor the query, or write it fast the first time)

crazygringoOP1y ago

> Latency and bandwidth can be made 10x worst by process context switching alone.

No they can't. That doesn't even make sense as a claim regarding bandwidth since SQLite doesn't use any, but please re-read what I said about being a 1% or 5% difference in speed. Not 10x.

bob10291y ago

Yes they absolutely can.

Same-core context switching costs a few microseconds.

Going across core complexes can cost tens to hundreds of microseconds.

These figures are several orders of magnitude (5-6) slower than L1 access on the same thread.

crazygringoOP1y ago

Hundreds of microseconds? L1 access? I don't have the faintest idea of what you're talking about.

Communication between processes is negligible compared to all of the sequential disk/SSD accesses and processing required for executing queries.

The database isn't stored in L1 and communication isn't taking hundreds of microseconds. I don't know where you're getting your information.

The fact that SQLite is in-process is primarily about simplicity and convenience, not performance. Performance can even be worse, e.g. due to the lack of a query cache.

j / k navigate · click thread line to collapse

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3921y ago

crazygringoOP1y ago

> Latency and bandwidth can be made 10x worst by process context switching alone.

No they can't. That doesn't even make sense as a claim regarding bandwidth since SQLite doesn't use any, but please re-read what I said about being a 1% or 5% difference in speed. Not 10x.

bob10291y ago

Yes they absolutely can.

Same-core context switching costs a few microseconds.

Going across core complexes can cost tens to hundreds of microseconds.

These figures are several orders of magnitude (5-6) slower than L1 access on the same thread.

crazygringoOP1y ago

Hundreds of microseconds? L1 access? I don't have the faintest idea of what you're talking about.

Communication between processes is negligible compared to all of the sequential disk/SSD accesses and processing required for executing queries.

The database isn't stored in L1 and communication isn't taking hundreds of microseconds. I don't know where you're getting your information.

The fact that SQLite is in-process is primarily about simplicity and convenience, not performance. Performance can even be worse, e.g. due to the lack of a query cache.

j / k navigate · click thread line to collapse