Re: Zstandard support for toast compression

В письме от пятница, 20 мая 2022 г. 23:17:42 MSK пользователь Stephen Frost
написал:

> While I generally agree that we want to provide extensibility in this
> area, given that we already have zstd as a compile-time option and it
> exists in other parts of the system, I don't think it makes sense to
> require users to install an extension to use it.
I mean that there can be Compression Method Provider, either built in postgres
core, or implemented in extension. And one will need to create Compression
method using desired Compression Method Provider. Like (it is just pure
imagination) CREATE COMPRESSION METHOD MY_COMPRESSION USING
'my_compression_provider'; This will assign certain bits combination to that
method, and later one can use that method for TOAST compression...

> > Moreover I guess this API (may be with some modification) can be used for
> > seamless data encryption, for example.
>
> Perhaps.. but this kind of encryption wouldn't allow indexing
Yes, this will require some more efforts. But for encrypting pure storage that
API can be quite useful.

> and certainly lots of other metadata would still be unencrypted (the entire
> system catalog being a good example..).
In many it is enough to encrypt only sensible information itself, not whole
metadata.
My point was not to discuss DB encryption, it is quite complex issue, my point
was to point out that API that allows custom compression methods may became
useful for other solutions. Encryption was just first example that came in my
mind. Robert Haas has another example for compression method optimized for
certain data type. So it is good if you can have method of your own.

--
Nikolay Shaplov aka Nataraj
Fuzzing Engineer at Postgres Professional
Matrix IM: @dhyan:nataraj.su