Обсуждение: Statistics from Sequences

• The sequence owner
• The min value
• The max value
• The increment value
• The last used number

???

Regards

On Tue, Sep 06, 2005 at 11:43:44PM -0300, Joÿffffffffffe3o Carvalho wrote:
> Is it possible to get from a sequence:
> 
>    The sequence owner
>    The min value
>    The max value
>    The increment value
>    The last used number

See the output from the following example:

CREATE SEQUENCE fooseq;

SELECT u.usename
FROM pg_class AS c JOIN pg_user AS u ON u.usesysid = c.relowner
WHERE c.relname = 'fooseq';

SELECT * FROM fooseq;

-- 
Michael Fuhr

On Tue, Sep 06, 2005 at 23:43:44 -0300, Joÿffffffffffe3o Carvalho <joaocarvalho127@yahoo.com.br> wrote:
> Is it possible to get from a sequence:
> 
>    The sequence owner
>    The min value
>    The max value
>    The increment value
>    The last used number

Yes. Associated with each sequence is a one row table with the name of the
sequence. Note that numbers can be allocated and not used, so the last_value
may not be exactly what you want.

To get the owner you can combine pg_class with pg_user to get the table
owner. I didn't see this information in the information schema.

[Please copy the mailing list on replies so others can participate
in and learn from the discussion.]

On Thu, Sep 08, 2005 at 02:32:12PM -0300, Joÿffffffffffe3o Carvalho wrote:
> Can you give me a help about:
> 
> >    The min value
> >    The max value
> >    The increment value
> >    The last used number

The example I posted shows how to obtain those values:

CREATE SEQUENCE fooseq;
SELECT * FROM fooseq;

If you want only particular columns then specify them:

SELECT min_value, max_value, increment_by, last_value FROM fooseq;

-- 
Michael Fuhr

[Again, please copy the mailing list on replies so others can
participate in and learn from the discussion.]

On Thu, Sep 08, 2005 at 06:25:33PM -0300, Joÿffffffffffe3o Carvalho wrote:
> There's one thing. If the sequence name was fooseq in uppercase
> (FOOSEQ) it does not work. In that case it returns the error: ERROR:
> relation "fooseq" does not exist.

This isn't a sequence issue, it's an identifier issue.  See "Why
are my table and column names not recognized in my query?" in the
FAQ and "Identifiers and Key Words" in the documentation:

http://www.postgresql.org/docs/faqs.FAQ.html#4.20
http://www.postgresql.org/docs/8.0/static/sql-syntax.html#SQL-SYNTAX-IDENTIFIERS

-- 
Michael Fuhr