Re: foreign data wrappers

Hi Guillaume,

Thanks very much! Your answers help a lot!

>
> Le 24/03/2011 06:39, Zheng Yang a écrit :
>
>> 4) Is theFDW something similar to the Mysql storage engine architecture?
>>
>
> Not really.

AFAIK,there is a CSV storage engine in MySql that serves as a wrapper, enable executing SQL queries directly on the
file.
This makes me think that the CSV FDW was doing similar things.

>
>> 5) for the datalink, the doc has mentioned about it's going to be OS dependent. but i dun quite understand how does
thekernel module and LD_PRELOAD will work in this case, esp.LD_PRELOAD. 
>>
>
> No idea.
>
I am quite new to postgresql, but slowly picking up :)  In general context, storing images directly inside DBMS fields
asBLOBs was not considered as a good practice.  
However, storing file directories  or links may cause inconsistency. So I am quite interested in how this datalink
conceptcan be implemented!  


> Writing some FDWs would make a really good GSoC project.
Haha, agree!  I believe that's also a great starting point for learning pgsql internals.


cheers

ZY