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so, what about my argument that PG has 23 bytes overhead per row and your space win is very small compared to that overhead?

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It’s orthogonal, and also technically incorrect – the row overhead itself is indeed 23 bytes (less NULL bitmap), but it gets aligned to 24 bytes. Run pg_column_size(ROW()) if you’d like to check.

The fact that this overhead exists has nothing to do with the 8.6 GB of wasted space on the INTs.

> It’s orthogonal

I disagree its orthogonal and explained why. I guess lets agree on disagree.

Is that an innate property or a current implementation detail?

price for various features, like ACID.

It’s the current implementation as of PG 8.2, I think. It’s [0] been there for a long time, in any case, and is unlikely to change in the near future.

[0]: https://www.postgresql.org/docs/current/storage-page-layout....

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