Re: Sort question - Fractions, Metric etc

Of course it's a complete disorganized mess..That'a the world I live in.Best thing is, I'm walking away with some new strategies.You guys rock
-------- Original message --------From: Sándor Daku <daku(dot)sandor(at)gmail(dot)com> Date: 8/14/21 10:19 AM (GMT-08:00) To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> Cc: Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com>, Bret Stern <bret_stern(at)machinemanagement(dot)com>, pgsql-general(at)lists(dot)postgresql(dot)org Subject: Re: Sort question - Fractions, Metric etc On Sat, 14 Aug 2021 at 19:03, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com> writes:
> On 8/14/21 9:37 AM, Bret Stern wrote:
>> I haven't explored doing this with numeric types, but some columns
>> needed alpha chars eg 13mm.

> Two columns:

> data_val(numeric)     data_unit(varchar)
> 13                    mm

It sounds like your data is a completely disorganized mess :-(.
You might be able to bring some semblance of coherence to it with
an extension like postgresql-unit [1], but it will take a lot of
effort to get the data into a representation that can sort reasonably.
There's no "easy button" here.

                        regards, tom lane

[1] https://github.com/df7cb/postgresql-unitI'm not sure, but maybe a kind of cast function that cast everything into a reasonable common unit(Khm... millimeters) and sort on that? It seems relatively simple to pick up the value and unit from a string with a regexp. Admittedly the data would still be a mess.  Regards,Sándor