Re: inherit support for foreign tables

Hello, I have a request with slight significance for the messages.

> I'd like to address this by emitting the second message as shown below:
> 
> INFO:  analyzing "public.parent"
> INFO:  "parent": scanned 0 of 0 pages, containing 0 live rows and 0 dead 
> rows; 0 rows in sample, 0 estimated total rows
> INFO:  analyzing "public.parent" inheritance tree
> INFO:  skipping analyze of "public.parent" inheritance tree --- this 
> inheritance tree contains foreign tables

In acquire_inherited_sample_rows(), the message below is emitted
when the parent explicitly specified in analyze command has at
least one foreign tables.

>    "skipping analyze of \"%s.%s\" inheritance tree --- this
>     inheritance tree contains foreign tables"

This message implicitly asserts (for me) that "A inheritance tree
containing at least one foreign tables *always* cannot be
analyzed" but in reality, we can let it go by specifying the
parent table explicitly. For example, the additional HINT or
DETAIL message would clarify that.

> INFO:  analyzing "public.parent" inheritance tree
> INFO:  skipping analyze of "public.parent" inheritance tree --- this 
> inheritance tree contains foreign tables
+ HINT:  You can analyze this inheritance tree by specifying "public.parent" to analze command

-- 
Kyotaro Horiguchi
NTT Open Source Software Center