Thread: Determine index's attribute number by scankey

Determine index's attribute number by scankey

From
Victor Yegorov
Date:
Hello.

Is it possible to somehow determine index's attribute number that is target
one for given scankey?


I've checked nbtree AM code and found no evidence of such an ability. I need
that, because I'm storing each indexed value only once in a form of index
tuple, consisting of only 1 attribute.

If that's not possible now, I'd like to add sk_index_attnum entry to the
ScanKeyData structure.


-- 

Victor Y. Yegorov


Re: Determine index's attribute number by scankey

From
Tom Lane
Date:
Victor Yegorov <viy@mits.lv> writes:
> Is it possible to somehow determine index's attribute number that is target
> one for given scankey?

sk_attno?
        regards, tom lane


Re: Determine index's attribute number by scankey

From
Victor Yegorov
Date:
* Tom Lane <tgl@sss.pgh.pa.us> [14.07.2005 01:00]:
> sk_attno?

It seems, that sk_attno holds number of scankey itself.

I have table with 3 columns (a, b, c) and index (b, c).
For both selects (only 1 where clause in both of them):
   select * from tab where b = ...

and
   select * from tab where c = ...


sk_attno reports 0, that made me think of adding new entry to the scankey.


-- 

Victor Y. Yegorov