Re: Question regarding Sync message and unnamed portal

> On Sat, Jan 26, 2013 at 09:25:56AM +0900, Tatsuo Ishii wrote:
>> Sorry for confusion.
>> 
>> I knew an unamed portal only lasts until current transaction ends.  I
>> was confused in the case when no explicit transaction is used.
>> 
>>   At completion of each series of extended-query messages, the
>>   frontend should issue a Sync message.
>> 
>> This is not actually true because Sync is not actually mandatory as
>> Tom pointed out before. We could use a Flush message instead but it's
>> another story. And next sentence says:
>> 
>>  This parameterless message causes the backend to close the current
>>   transaction if it's not inside a BEGIN/COMMIT transaction block
>>   ("close" meaning to commit if no error, or roll back if error).
>> 
>> I did not understand this at first because if we are not inside a
>> BEGIN/COMMIT transaction block, how does Sync close it? In my
>> understanding each extended query message(parse/bind/execute) starts
>> an internal transaction and does not close it until Sync issued(and
>> Sync is mandatory according to the manual). So if we are not in an
>> explicit transaction we cannot reuse unnamed portal because Sync
>> closes the transaction, which in turn destroys the unnamed portal.
>> This gave me a miss understanding that unnamed portal is destroyed
>> even transaction is not explicitly closed.
>> 
>> It would be nice if something like "unnamed portal will be destroyed
>> by a Sync message if you are in an explicit transaction" is in our
>> manual.
> 
> I am back to this issue and still confused.  Perhaps if I give some
> specific examples it will help.
> 
> Based on the current documentation, I assume that if you do an explicit
> transaction (BEGIN WORK), Sync will not close any portals.  For an
> implicit transaction, I assume Sync will close all portals except FOR
> HOLD named portals.  Is this not how it behaves?

Sorry for confusion. I wanted to say:

> It would be nice if something like "unnamed portal will be destroyed
> by a Sync message if you are in an implicit transaction" is in our
> manual.
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp