I like programming and anime.

I manage the bot /u/mahoro@lemmy.ml

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Joined 1 year ago
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Cake day: June 12th, 2023

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  • I also like the POSIX “seconds since 1970” standard, but I feel that should only be used in RAM when performing operations (time differences in timers etc.). It irks me when it’s used for serialising to text/JSON/XML/CSV.

    I’ve seen bugs where programmers tried to represent date in epoch time in seconds or milliseconds in json. So something like “pay date” would be presented by a timestamp, and would get off-by-one errors because whatever time library the programmer was using would do time zone conversions on a timestamp then truncate the date portion.

    If the programmer used ISO 8601 style formatting, I don’t think they would have included the timepart and the bug could have been avoided.

    Use dates when you need dates and timestamps when you need timestamps!


  • Jim@programming.devtoProgramming@programming.devparquet vs csv
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    2 months ago

    Do you use it? When?

    Parquet is really used for big data batch data processing. It’s columnar-based file format and is optimized for large, aggregation queries. It’s non-human readable so you need a library like apache arrow to read/write to it.

    I would use parquet in the following circumstances (or combination of circumstances):

    • The data is very large
    • I’m integrating this into an analytical query engine (Presto, etc.)
    • I’m transporting data that needs to land in an analytical data warehouse (Snowflake, BigQuery, etc.)
    • Consumed by data scientists, machine learning engineers, or other data engineers

    Since the data is columnar-based, doing queries like select sum(sales) from revenue is much cheaper and faster if the underlying data is in parquet than csv.

    The big advantage of csv is that it’s more portable. csv as a data file format has been around forever, so it is used in a lot of places where parquet can’t be used.






  • Just because you can get part of your education remotely or through self-learning didn’t mean “anything can be learned online”.

    And if you were hiring a math tutor for your kid, would you prefer a self-proclaimed expert from watching YouTube videos or would you want someone who got a degree from a credentialed university? And even if you don’t care, why are you surprised that others would be skeptical of the YouTube expert?

    Remote learning can be fine for some things, and self learning through informal channels are also fine, but it’s not a full on replacement for formal education in all cases.








  • Most of us have bad memories of over-complex hierarchies we regret seeing, but this is probably due to the dominance of OOP in recent decades.

    This sentence here is why inheritance gets a bad reputation, rightly or wrongly. Inheritance sounds intuitive when you’re inheriting Vehicle in your Bicycle class, but it falls apart when dealing with more abstract ideas. Thus, it’s not immediately clear when and why you should use inheritance, and it soon becomes a tangled mess.

    Thus, OO programs can easily fall into a trap of organizing code into false hierarchies. And those hierarchies may not make sense from developer to developer who is reading the code.

    I’m not a fan of OO programming, but I do think it can occasionally be a useful tool.


  • If the work I’m doing is on a feature branch on remote or locally, why does it matter to the rest of the team? My integration steps can be done on a server instead of locally. TBD forces teams to collaborate synchronously since changes are pushed straight to trunk. Rebase or squashes are irrelevant here.

    Another poster put it great: TBD is trying to solve a culture problem. Feature branches and pull requests into main is much more flexible. The only time TBD make sense is for small teams - like 2 or maybe 3. And even at 2, I’d much rather create feature branches that merge into main.