Tom Lane wrote:
> Andrew Dunstan <andrew(at)dunslane(dot)net> writes:
>   
>> OK, here is a patch that I think incorporates all the ideas discussed 
>> (including part of Mark Mielke's suggestion about optimising %_). There 
>> is now no special treatment of UTF8 other than its use of a faster 
>> NextChar macro.
>>     
>
> Looks mostly pretty good.  I would suggest replacing tests "tlen == 0"
> and "plen == 0" with "<= 0", just so the code doesn't go completely
> insane if presented with invalidly-encoded data that causes it to step
> beyond the end of data.  Also, this comment is not really good enough:
>
>   
>> ! 		/*
>> ! 		 * It is safe to use NextByte instead of NextChar here, even for
>> ! 		 * multi-byte character sets, because we are not following 
>> ! 		 * immediately after a wildcard character.
>> ! 		 */
>> ! 		NextByte(t, tlen);
>> ! 		NextByte(p, plen);
>>   	}
>>     
>
> I'd suggest adding something like "If we are in the middle of a
> multibyte character, we must already have matched at least one byte of
> the character from both text and pattern; so we cannot get out-of-sync
> on character boundaries.  And we know that no backend-legal encoding
> allows ASCII characters such as '%' to appear as non-first bytes of
> characters, so we won't mistakenly detect a new wildcard."
>
> 			
>   

Done, and committed.

cheers

andrew

In response to

• Re: [HACKERS] like/ilike improvements at 2007-06-01 22:54:04 from Tom Lane

Responses

• Re: [HACKERS] like/ilike improvements at 2007-06-02 02:15:13 from Bruce Momjian

pgsql-hackers by date

Next:	From: Bruce Momjian	Date: 2007-06-02 02:15:13
	Subject: Re: [HACKERS] like/ilike improvements
Previous:	From: Andrew Dunstan	Date: 2007-06-02 01:11:54
	Subject: Re: syslogger line-end processing infelicity

pgsql-patches by date

Next:	From: Bruce Momjian	Date: 2007-06-02 02:15:13
	Subject: Re: [HACKERS] like/ilike improvements
Previous:	From: Tom Lane	Date: 2007-06-01 22:58:18
	Subject: Re: [HACKERS] like/ilike improvements