Constantin Stefanov wrote:
>
>I do not suggest PgAdmin to become 'psql with GUI'. They are different
>applications. But in some questionable issues I would suggest to use
>psql as a reference, because it constains almost everything that is
>needed for everyday work.
>In case I explained PgAdmin does not provide enough information for
>work, so I need to use another tool (psql). I am speaking only about
>making PgAdmin fully sufficient for all the work which may be done
>through database support.
>Let me introduce 2 scenarios which explains what I mean.
>Prologue is the same in both - creating table (I write SQL, but when I
>stepped into the bug, I was doing the same with PgAdmin GUI).
>CREATE TABLE test (
> a int,
> b int,
> PRIMARY KEY(a)
>);
>Now implicit index on column a is created, but it is not shown by PgAdmin.
>I populate table with some data, use VACUUM ANALYZE to compute
>statictics. Then I write query something like that
>SELECT sum(b) WHERE a BETWEEN 1 AND 5;
>Then 2 possible continuations.
>1. I run EXPLAIN on that query, see index scan and begin to search for a
>bug (I don't see index). Possible places for bug: planner (decides to
>use index which is not present), PgAdmin (erraticaly parsing output),
>PgAdmin (not showing index). The last is the true, but to realize it I
>had to check with psql. Therefore - PgAdmin is not enough for
>understanding what is happening.
>2. I try to optimize query and create index with PgAdmin. Now I have 2
>almost equivalent indexes wasting space and time. If planner decides to
>use index created when creating primary key, we will come to scenario 1.
>If it uses manually created index, I will not see that I have
>unneseccary index which consumes disk space and processor time while
>inserting new rows.
>
>I got that it is quite a hard work to make PgAdmin show indexes from
>primary key while not breaking other things. But I think it would be
>nice if it falls into TODO list (as a distant entry or simply as a
>suggestion).
>
>
Well it's not really hard, just some things to think of. And the longer
I think about it, and looking at your example, I'd say people analyzing
a query should know a little what pgsql is doing, e.g. that unique and
primary constraints include an index. Thus I tend to say we'll stay with
what we got now.
Regards,
Andreas
