Re: Indirect indexes

On 2016-10-18 20:04:32, Claudio Freire wrote:

> You don't need that limitation (and vacuum will be simpler) if you add
the PK as another key, akin to:
>
> CREATE INDIRECT INDEX idx ON tab (a, b, c);
>
> turns into
>
> CREATE INDEX idx ON tab (a, b, c, pk);

I know I am late to this point but I wanted to present my mere user's
point of view.

First I liked it, as does not introduce yet another syntax to learn.
However, after following the discussion, I see that indirect indexes
have their disadvantages/slowdowns as well. If adding "pk" to the end of
the column list just converts the index to an indirect index, I am
unable to use a direct index which might be better in certain cases.

So, from a "dumb" user's point of view, I wonder if PostgreSQL can make
the right decision of direct/indirect reliably (which would be great).
And if not, what would be the alternatives? Introducing CREATE DIRECT INDEX?

Cheers,
Sven

PS: I mot saying I would be affected by this but IIRC we have (..., pk)
indexes in production which then would be converted to indirect ones.
But I cannot tell whether indirect indexes would do good or harm there.