Andreas Pflug wrote:
>> I have PgAdmin III 1.0.2 and PostgreSQL 7.4.1.
>> When I create a table with primary key constraint on it, PostgreSQL
>> automatically creates an index on that column (or columns), which is
>> then shown in psql with \di command.
>> But PgAdmin does not show that index in
>> ...Tables-> <table name> -> Indexes in the left frame.
>> Sometimes it is useful to see all indexes on the table (for example,
>> when trying to understand planner decisions), because planner makes use
>> of those indexes.
>>
>> So I suggest PgAdmin to show all indexes (user and system-generated) or
>> to have an option to show them all.
>>
> These indexes (primary and unique if defined by constraint) are filtered
> out intentionally, but I see your point about the planner. Making them
> display would be a little more complicated than it seems, because we
> need to avoid having them duplicated in the table's definition pane
> (once as constraint, once as index).
Why should such duplication be avoided? There is both constraint
(primary key) and index. Constraint is something logical, index is a way
to implement it. When I 'connect' a trigger to a table, there is trigger
as a function, and trigger usage for a table. Yes, index is more tightly
connected with its table, but in a case of a constraint it is still an
index but system-generated.
And if it would be an option to show such indexes, such duplication is
not a problem at all - if you turn this option on (it may be off by
default), you know what you are doing and know that some constraints may
be duplicated as indexes.
--
Constantin Stefanov