Horton

Re: custom function for converting human readable sizes to bytes

Vitaly Burovoy <vitaly.burovoy@gmail.com>

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From: Vitaly Burovoy <vitaly.burovoy@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Pavel Stehule <pavel.stehule@gmail.com>, "Shulgin, Oleksandr" <oleksandr.shulgin@zalando.de>, Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>, Alvaro Herrera <alvherre@2ndquadrant.com>, Tom Lane <tgl@sss.pgh.pa.us>, Jim Nasby <Jim.Nasby@bluetreble.com>, Corey Huinker <corey.huinker@gmail.com>, Guillaume Lelarge <guillaume@lelarge.info>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2016-01-18T23:56:35Z
Lists: pgsql-hackers 
On 1/4/16, Robert Haas <robertmhaas@gmail.com> wrote:
> On Mon, Jan 4, 2016 at 10:17 AM, Pavel Stehule <pavel.stehule@gmail.com>
> wrote:
>> [ new patch ]
>
> +         case '-':
> +             ereport(ERROR,
> +                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
> +                      errmsg("size cannot be negative")));
>
> Why not?  I bet if you copy any - sign to the buffer, this will Just Work.

Hmm. The function's name is pg_size_bytes. How number of bytes can be
negative? How any length can be negative? If anyone insert '-' sign to
an argument, it is copy-paste error. I don't see any case where there
is possible negatives as input value.

I prefer error message instead of getting all relations (by using
comparison from the initial letter) just because of copy-paste mistake
or incomplete checking of input values at app-level.

> ...
>
> --
> Robert Haas
> EnterpriseDB: http://www.enterprisedb.com
> The Enterprise PostgreSQL Company

-- 
Best regards,
Vitaly Burovoy

Commits

  1. Add pg_size_bytes() to parse human-readable size strings.

  2. Refactor check_functional_grouping() to use get_primary_key_attnos().

  3. Correct comment in GetConflictingVirtualXIDs()

  4. Make extract() do something more reasonable with infinite datetimes.

  5. pg_size_pretty: Format negative values similar to positive ones.

  6. pg_size_pretty(numeric)