[Pgpool-hackers] First try at rephrasing the documentation

[Guillaume Lelarge]

Le 05/01/2011 10:45, Guillaume Lelarge a écrit :
> Le 05/01/2011 10:38, Tatsuo Ishii a écrit :
>>> The Wednesday 05 January 2011 02:37:52, Tatsuo Ishii wrote :
>>>>>> I proofreaded Marc's rewrite. It's mostly really good, but there are a
>>>>>> few mistakes. Patch attached fixes them. The whole new file is also
>>>>>> attached (with Marc's patch and mine).
>>>>>>
>>>>>> So I think all is need is to put the last bit of informations Tatsuo
>>>>>> gave you, to have a complete file.
>>>>>>
>>>>>> Thanks for your work.
>>>>>
>>>>> Here is another patch (version 3) to be applied on top of this one.
>>>>>
>>>>> There are 3 items left (missing answers):
>>>>>
>>>>>
>>>>> In the replication mode or master/slave mode, trust, clear text
>>>>>
>>>>>       password, and pam methods are supported.
>>>>>       
>>>>>            clear text password is not supported. TODO: contradiction in
>>>>>            the
>>>>>
>>>>> previous sentence
>>>>
>>>> In the replication mode or master/slave mode, trust, clear text
>>>> password, and pam methods are supported. From pgpool-II 3.0 md5 is
>>>> also supported.
>>>>
>>>>> <code>JOIN</code>s like above will be executed on each backend, and
>>>>> then merged with the results returned by each backend. Views and Rules
>>>>> that join across the nodes cannot be created.
>>>>> This VIEW is registered in the pgpool_catalog.dist_def table. A col_name
>>>>> and a dist_def_func will have to be registered too. These are used when
>>>>> an insert is
>>>>> performed on the view.
>>>>> </p> TODO: I don't really get this one
>>>>>
>>>>> <code>JOIN</code>s like above will be executed on each backend, and
>>>>> then merged with the results returned by each backend.
>>>>
>>>> I assume you get this paragraph.
>>>>
>>>>> Views and Rules
>>>>> that join across the nodes cannot be created.
>>>>> However, to JOIN tables that access data only in the same node, a VIEW
>>>>> can be made.
>>>>
>>>> I think this one just says unlike explicit JOINs, the results of the
>>>> VIEWs are not automatically merged.
>>>>
>>>>> The column names and types are needed when a query is analyzed in
>>>>> parallel mode.
>>>>> Therefore, when an expression or a function is used in the TARGETLIST of
>>>>> a subquery, the alias and type (through a cast) are needed. Please note
>>>>> that if no cast is provided in an expression or a function, the text
>>>>> type will be chosen as a default. For count(), bigint type is assumed,
>>>>> and for sum(), numeric. For min()/max(), if the argument is a date type,
>>>>> returned datatype is date,
>>>>> else, it is assumed numeric. avg() is processed as sum/count.
>>>>> TODO : which one ? numeric or bigint ?
>>>>
>>>> This one says "avg()" is rewritten to "sum()/count()". Thus the
>>>> returned data type of "sum()/count()" is determined by PostgreSQL.
>>>> --
>>>
>>>
>>> Thanks.
>>>
>>> I've corrected the last TODOs, there are no longer any in the document. As far 
>>> as I'm concerned, this version is OK :)
>>
>> Thanks. Guillaume, could you please commit this if you are
>> comfortable? Because you have done extensive proof reading.
> 
> Sure, I take care of this. Thanks you both.
> 

Commited to the 3.0 branch (as it was a 3.0 document), and to HEAD (with
the HEAD updates).

Thanks, Marc.


-- 
Guillaume
 http://www.postgresql.fr
 http://dalibo.com