Re: custom function for converting human readable sizes to bytes - Mailing list pgsql-hackers

From Pavel Stehule
Subject Re: custom function for converting human readable sizes to bytes
Date
Msg-id CAFj8pRA9zOCxgKx1jmsUdpzKEZAg-VT4uXe2mEG6DZtPiXU_qQ@mail.gmail.com
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In response to Re: custom function for converting human readable sizes to bytes  (Dean Rasheed <dean.a.rasheed@gmail.com>)
Responses Re: custom function for converting human readable sizes to bytes
List pgsql-hackers
Hi

2016-02-15 10:16 GMT+01:00 Dean Rasheed <dean.a.rasheed@gmail.com>:
> On 12/02/16 10:19, Dean Rasheed wrote:
>> This seems like a reasonable first patch for me as a committer, so
>> I'll take it unless anyone else was planning to do so.
>

So looking at this, it seems that for the most part pg_size_bytes()
will parse any output produced by pg_size_pretty(). The exception is
that there are 2 versions of pg_size_pretty(), one that takes bigint
and one that takes numeric, whereas pg_size_bytes() returns bigint, so
it can't handle all inputs. Is there any reason not to make
pg_size_bytes() return numeric? 

It would still be compatible with the example use cases, but it would
be a better inverse of both variants of pg_size_pretty() and would be
more future-proof. It already works internally using numeric, so it's
a trivial change to make now, but impossible to change in the future
without introducing a new function with a different name, which is
messy.

Thoughts?

This is a question. I have not a strong opinion about it. There are no any technical objection - the result will be +/- same. But you will enforce Numeric into outer expression evaluation.

The result will not be used together with function pg_size_pretty, but much more with functions pg_relation_size, pg_relation_size, .. and these functions doesn't return Numeric. These functions returns bigint. Bigint is much more natural type for this purpose.

Is there any use case for Numeric?

Regards

Pavel
 

Regards,
Dean

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