Re: proposal - patch: psql - sort_by_size

Hi

pá 12. 7. 2019 v 15:10 odesílatel Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr>
napsal:

>
> Hello Pavel,
>
> > rebased patch attached
>
> I prefer patches with a number rather than a date, if possible. For one
> thing, there may be several updates in one day.
>
> About this version (20180708, probably v3): applies cleanly, compiles,
> make check ok, doc build ok. No tests.
>

attached version 4

> It works for me on a few manual tests against a 11.4 server.
>
> Documentation: if you say "\d*+", then it already applies to \db+ and
> \dP+, so why listing them? Otherwise, state all commands or make it work
> on all commands that have a size?
>
> About the text:
> - remove , before "sorts"
> - ... outputs by decreasing size, when size is displayed.
> - add: When size is not displayed, the output is sorted by names.
>

fixed

> I still think that the object name should be kept as a secondary sort
> criterion, in case of size equality, so that the output is deterministic.
> Having plenty of objects of the same size out of alphabetical order looks
> very strange.
>

fixed

Regards

Pavel

>
> I still do not like much the boolean approach. I understand that the name
> approach has been rejected, and I can understand why.
>
> I've been thinking about another more generic interface, that I'm putting
> here for discussion, I do not claim that it is a good idea. Probably could
> fall under "over engineering", but it might not be much harder to
> implement, and it solves a few potential problems.
>
> The idea is to add an option to \d commands, such as "\echo -n":
>
> \dt+ [-o 1d,2a] ...
>
> meaning do the \dt+, order by column 1 descending, column 2 ascending.
> With this there would be no need for a special variable nor other
> extensions to specify some ordering, whatever the user wishes.
>
> Maybe it could be "\dt+ [-o '1 DESC, 2 ASC'] ..." so that the string
> is roughly used as an ORDER BY specification by the query, but it would be
> longer to specify.
>
> It also solves the issue that if someone wants another sorting order we
> would end with competing boolean variables such as SORT_BY_SIZE,
> SORT_BY_TYPE, SORT_BY_SCHEMA, which would be pretty unpractical. The
> boolean approach works for *one* sorting extension and breaks at the next
> extension.
>
> Also, the boolean does not say that it is a descending order. I could be
> interested in looking at the small tables.
>
> Another benefit for me is that I do not like much variables with side
> effects, whereas with an explicit syntax there would be no such thing, the
> user has what was asked for. Ok, psql is full of them, but I cannot say I
> like it for that.
>
> The approach could be extended to specify a limit, eg \dt -l 10 would
> add a LIMIT 10 on the query.
>
> Also, the implementation could be high enough so that the description
> handlers would not have to deal with it individually, it could return
> the query which would then be completed with SORT/LIMIT clauses before
> being executed, possibly with a default order if none is specified.
>
> --
> Fabien.
>
>
>