Re: Fuzzy substring searching with the pg_trgm extension

> Sure. I attached two patches. But notice that pg_trgm.limit should be used with
> this command:
> SHOW "pg_trgm.limit";
> If you will use this command:
> SHOW pg_trgm.limit;
> you will get the error:
> ERROR:  syntax error at or near "limit"
> LINE 1: SHOW pg_trgm.limit;
>                       ^
>
> This is because "limit" is keyword I think.

It's easy to fix in gram.y:
@@ -1499,7 +1499,7 @@ set_rest_more:    /* Generic SET syntaxes: */        ;
 var_name:  ColId                               { $$ = $1; }
-           | var_name '.' ColId
+           | var_name '.' ColLabel                { $$ = psprintf("%s.%s", $1, $3); }        ;

ColId doesn't contain reserved_keyword, it's impossible to change initial part 
of var_name to ColId because of a lot of conflicts in grammar but could be easy 
changed for second part of var_name. It seems like improvement in any case but
sml_limit or similarity_limit or even similarity_treshold  is more preferable 
name than just simple limit. In future we could introduce more tresholds/limits.

Also, should get/set_limit emit a warning about deprecation?

Some notices about substring patch itself:
1  trgm2.data contains too much duplicates (like Barkala or Bakalan). Is it 
really needed for testing?

2 I'm agree with Jeff Janes about <<-> and <->> operation. They are needed. 
(http://www.postgresql.org/message-id/CAMkU=1zynKQfkR-J2_Uq8Lzp0uho8i+LEdFwGt77CzK_tNtN7g@mail.gmail.com)

-- 
Teodor Sigaev                                   E-mail: teodor@sigaev.ru
  WWW: http://www.sigaev.ru/