Thanks for sharing, I've been interested in finding pure python implementations of storage engines. Another one I came across is whoosh: https://bitbucket.org/mchaput/whoosh/src/a16ebacb47191afaf2d...
Show HN: On-disk B+ tree for Python 3
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Re: Show HN: On-disk B+ tree for Python 3
#12The code looks very clean. Uses type annotations too. Wish there were more comments though.
Re: Show HN: On-disk B+ tree for Python 3
#13Thanks for sharing, I've been interested in finding pure python implementations of storage engines. Another one I came across is whoosh: https://bitbucket.org/mchaput/whoosh/src/a16ebacb47191afaf2d...
Check out zodb and durus.
Re: Show HN: On-disk B+ tree for Python 3
#14This is pretty cool. As I was reading the code I really wished for an explanation or simple ASCII diagram of the serialization formats for the various node/record types, as well as for the frames/wal format. Given that the poster is the author of the project, I hope you'll consider filling in these kinds of details, as they'd presumably be of interest to the people you're "Show"-ing this to.
Re: Show HN: On-disk B+ tree for Python 3
#15Are there any production data stores recommended for low memory usage? What should I use to stream data to disk and back with minimal overhead, preferably with indexed lookups?
Re: Show HN: On-disk B+ tree for Python 3
#16Cannot delete items yet
Yes, it's a work in progress, see the `remove` branch.
Why is this not mentioned very clearly in the README? Seems like willful misrepresentation.
You might also mention that, if replacing large values that use overflow pages, the file has the potential to grow without bounds as it looks like overflow pages are not collected?
Re: Show HN: On-disk B+ tree for Python 3
#17what about using a DB?
Is there any really simple database for the same purpose?
Re: Show HN: On-disk B+ tree for Python 3
#18Are there any production data stores recommended for low memory usage? What should I use to stream data to disk and back with minimal overhead, preferably with indexed lookups?
An SSD with the highest random-read/write IOPS you can afford. Something like this:
https://www.computerworld.com/article/2987956/solid-state-dr...
Or FusionIO ioDrive2 Duo, which is above 900K IOPS for both reads and writes.
Re: Show HN: On-disk B+ tree for Python 3
#19How does this perform compared to sqlite3?
And and can you use keys that aren't builtin values?
Re: Show HN: On-disk B+ tree for Python 3
#20The code looks very clean. Uses type annotations too. Wish there were more comments though.
Thank you! I found that type annotations make code easier to read so I tend to write less comments. But I'll make an effort.