Horton

Re: proposal: minscale, rtrim, btrim functions for numeric

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Pavel Stehule <pavel.stehule@gmail.com>
Cc: "Karl O. Pinc" <kop@meme.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Marko Tiikkaja <marko@joh.to>, Dean Rasheed <dean.a.rasheed@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Robert Haas <robertmhaas@gmail.com>
Date: 2020-01-06T17:22:50Z
Lists: pgsql-hackers 
Pavel Stehule <pavel.stehule@gmail.com> writes:
> út 10. 12. 2019 v 13:56 odesílatel Karl O. Pinc <kop@meme.com> napsal:
>> I'm marking it ready for a committer.

> Thank you for review

Pushed with minor adjustments.  Notably, I didn't like having
get_min_scale() depend on its callers having stripped trailing zeroes
to avoid getting into a tight infinite loop.  That's just trouble
waiting to happen, especially since non-stripped numerics are seldom
seen in practice (ones coming into the SQL-level functions should
never look like that, ie the strip_var calls you had are almost
certainly dead code).  If we did have a code path where the situation
could occur, and somebody forgot the strip_var call, the omission
could easily escape notice.  So I got rid of the strip_var calls and
made get_min_scale() defend itself against the case.  It's hardly
any more code, and it should be a shade faster than strip_var anyway.

			regards, tom lane

Commits

  1. Add functions min_scale(numeric) and trim_scale(numeric).