Re: 1.10 beta 1

wow - Thanks.
I think - this gives me enough idea to work on.
Guillaume Lelarge wrote:
> Ashesh Vashi a écrit :
>
>> Hi Guillaume,
>>
>> Thanks for reviewing the patch.
>>
>> Guillaume Lelarge wrote:
>>
>>> Ashesh Vashi a écrit :
>>>
>>>> Hi Dave,
>>>>
>>>> Please find the patch for the Dependency bug
>>>>
>>> I just checked this patch. I find disturbing that it finds a dependency
>>> to a nextval function instead of a dependency to the sequence. Moreover,
>>> the first table has two dependencies : on the sequence and on the
>>> nextval function of this sequence.
>>>
>> I think - you're right.
>> But, I could not find the direct dependency of the sequence on the table.
>>
>>> This patch is a first step, but I think we need to go further.
>>>
>> Definitely, even I felt the same.
>> I need some guidance for it.
>>
>> Could you please help on this?
>>
>>
>
>
> Here are the definition of the two tables:
>
> CREATE TABLE t1 (id serial NOT NULL);
> CREATE TABLE t2 (LIKE t INCLUDING DEFAULTS);
>
> Quite simple. t1_id_seq must be a dependency of t2 (ie you can't drop
> t1_id_seq, or t1, without dropping t2 or at least change its sequence).
>
> With this next query, we get every pg_attrdef dependencies:
>
> ioguix=# select * from pg_depend where classid = 2604;
> classid | objid | objsubid | refclassid | refobjid | refobjsubid | deptype
> ---------+--------+----------+------------+----------+-------------+---------
> 2604 | 122030 | 0 | 1259 | 122027 | 1 | a
> 2604 | 122030 | 0 | 1259 | 122025 | 0 | n
> 2604 | 122034 | 0 | 1259 | 122031 | 1 | a
> 2604 | 122034 | 0 | 1259 | 122025 | 0 | n
> (4 lignes)
>
> This one gives us the target column (122030 and 122034 are results of
> the previous query, column objid) :
>
> ioguix=# select relname||'.'||attname
> from pg_class cl, pg_attribute att, pg_attrdef atd
> where atd.oid in (122030, 122034)
> and atd.adrelid=att.attrelid
> and atd.adnum=att.attnum
> and cl.oid=att.attrelid;
> ?column?
> ----------
> t1.id
> t2.id
> (2 lignes)
>
> This one gives us the referenced object (122027, 122025, 122031 are
> results of the attrdef query, column refobjid) :
>
> ioguix=# select oid, relname from pg_class where oid in (122027, 122025,
> 122031);
> oid | relname
> --------+-----------
> 122025 | t1_id_seq
> 122027 | t1
> 122031 | t2
> (3 lignes)
>
> In the first query (the attrdef one), you'll notice t1_id_seq appears
> two times, one for t1.id and one for t2.id.
>
> I don't quite know how to build a query that will give us t1_id_seq as a
> dependency to t2.
>
> I don't actually have the time to work on this right now. But it must be
> something with these queries.
>
> Hope it helps. Ping me if you need more details.
>
>
>

--
Regards,
Ashesh Vashi

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