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MVCC – the part of PostgreSQL we hate the most (2023)

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366 points virtualwhys | 1 comments | 20 Oct 24 15:30 UTC | HN request time: 0.205s | source
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nightfly ◴[20 Oct 24 18:26 UTC] No.41897421[source]▶
> MySQL and Oracle store a compact delta between the new and current versions (think of it like a git diff).

Doesn't git famously _not_ store diffs and instead follows the same storage pattern postgres uses here and stores the full new and old objects?

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1. epcoa ◴[20 Oct 24 23:00 UTC] No.41899189[source]▶
Others have mentioned that it said “git diffs”. However git does use deltas in pack files as a low level optimization, similar to the MySQL comparison. You don’t get back diffs from a SQL query either.