Re: like/ilike improvements

Tom Lane wrote:
> Andrew Dunstan <andrew@dunslane.net> writes:
>   
>> However, I have just about convinced myself that we don't need 
>> IsFirstByte for matching "_" for UTF8, either preceded by "%" or not, as 
>> it should always be true. Can anyone come up with a counter example?
>>     
>
> You have to be on a first byte before you can meaningfully apply
> NextChar, and you have to use NextChar or else you don't count
> characters correctly (eg "__" must match 2 chars not 2 bytes).
>
>
>   

Yes, I agree completely. However it looks to me like IsFirstByte will in 
fact always be true when we get to call NextChar for matching "_" for UTF8.

cheers

andrew