Re: Shared detoast Datum proposal

Michael Zhilin <m(dot)zhilin(at)postgrespro(dot)ru> writes:

> Hi Andy,
>
> It looks like v5 is missing in your mail. Could you please check and resend it?

ha, yes.. v5 is really attached this time.

commit eee0b2058f912d0d56282711c5d88bc0b1b75c2f (HEAD -> shared_detoast_value_v3)
Author: yizhi.fzh <yizhi(dot)fzh(at)alibaba-inc(dot)com>
Date: Tue Jan 23 13:38:34 2024 +0800

shared detoast feature.

details at https://postgr.es/m/87il4jrk1l.fsf%40163.com

commit eeca405f5ae87e7d4e5496de989ac7b5173bcaa9
Author: yizhi.fzh <yizhi(dot)fzh(at)alibaba-inc(dot)com>
Date: Mon Jan 22 15:48:33 2024 +0800

Introduce a Bitset data struct.

While Bitmapset is designed for variable-length of bits, Bitset is
designed for fixed-length of bits, the fixed length must be specified at
the bitset_init stage and keep unchanged at the whole lifespan. Because
of this, some operations on Bitset is simpler than Bitmapset.

The bitset_clear unsets all the bits but kept the allocated memory, this
capacity is impossible for bit Bitmapset for some solid reasons and this
is the main reason to add this data struct.

Also for performance aspect, the functions for Bitset removed some
unlikely checks, instead with some Asserts.

[1] https://postgr.es/m/CAApHDvpdp9LyAoMXvS7iCX-t3VonQM3fTWCmhconEvORrQ%2BZYA%40mail.gmail.com
[2] https://postgr.es/m/875xzqxbv5.fsf%40163.com

As for the commit "Introduce a Bitset data struct.", the test coverage
is 100% now. So it would be great that people can review this first.

--
Best Regards
Andy Fan