Re: Prefix operator for text and spgist support

On Thu, Mar 22, 2018 at 7:09 PM, Teodor Sigaev <teodor@sigaev.ru> wrote:

> Patch looks resonable, but I see some place to improvement:
> spg_text_leaf_consistent() only needs to check with text_startswith() if
> reconstucted value came to leaf consistent is shorter than given prefix.
> For example, if level >= length of prefix then we guarantee that fully
> reconstracted is matched too. But do not miss that you may need to return
> value for index only scan, consult returnData field
>
> In attachment rebased and minorly edited version of your patch.


I took a look at this patch.  In addition to Teodor's comments I can note
following.

* This line looks strange for me.

-			if (strategy > 10)
+			if (strategy > 10 && strategy != RTPrefixStrategyNumber)

It's not because we added strategy != RTPrefixStrategyNumber condition
there.
It's because we already used magic number here and now have a mix of magic
number and macro constant in one line.  Once we anyway touch this place,
could we get rid of magic numbers here?

* I'm a little concern about operator name.  We're going to choose @^
operator for
prefix search without any preliminary discussion.  However, personally I
don't
have better ideas :)

------
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company