Re: random() function documentation - Mailing list pgsql-hackers

From Fabien COELHO
Subject Re: random() function documentation
Date
Msg-id alpine.DEB.2.22.394.2204120950260.1378296@pseudo
Whole thread Raw
In response to Re: random() function documentation  (Dean Rasheed <dean.a.rasheed@gmail.com>)
Responses Re: random() function documentation  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
>>>> How about we just say "uses a linear-feedback shift register algorithm"?
>
> I think it'd be sufficient to just say that it's a deterministic
> pseudorandom number generator. I don't see much value in documenting
> the internal algorithm used.

Hmmm… I'm not so sure. ISTM that people interested in using the random 
user-facing variants (only random?) could like a pointer on the algorithm 
to check for the expected quality of the produced pseudo-random stream?

See attached.

>>> Should we perhaps also add a warning that the same seed is not 
>>> guaranteed to produce the same sequence across different (major?) 
>>> versions?
>>
>> I wouldn't bother, on the grounds that then we'd need such disclaimers
>> in a whole lot of places.  Others might see it differently though.
>
> Agreed,

Agreed.

> though I think when the release notes are written, they ought
> to warn that the sequence will change with this release.

Yes.

-- 
Fabien.
Attachment

pgsql-hackers by date:

Previous
From: Julien Rouhaud
Date:
Subject: Re: Unable to connect to Postgres13 server from psql client built on master
Next
From: Peter Smith
Date:
Subject: Re: PG DOCS - logical replication filtering