diff options
Diffstat (limited to 'src/backend/parser/gram.y')
| -rw-r--r-- | src/backend/parser/gram.y | 37 |
1 files changed, 25 insertions, 12 deletions
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index c038f43caa..bb36c6f042 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -10,7 +10,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.83 1999/05/22 05:06:43 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.84 1999/06/07 14:28:25 tgl Exp $ * * HISTORY * AUTHOR DATE MAJOR EVENT @@ -5357,6 +5357,7 @@ static Node *makeIndexable(char *opname, Node *lexpr, Node *rexpr) int pos, match_pos=0; bool found_special = false; + /* Cannot optimize if unquoted | { } is present in pattern */ for (pos = 1; n->val.val.str[pos]; pos++) { if (n->val.val.str[pos] == '|' || @@ -5367,12 +5368,16 @@ static Node *makeIndexable(char *opname, Node *lexpr, Node *rexpr) break; } if (n->val.val.str[pos] == '\\') + { pos++; + if (n->val.val.str[pos] == '\0') + break; + } } - /* skip leading ^ */ if (!found_special) { + /* note start at pos 1 to skip leading ^ */ for (pos = 1; n->val.val.str[pos]; pos++) { if (n->val.val.str[pos] == '.' || @@ -5383,9 +5388,11 @@ static Node *makeIndexable(char *opname, Node *lexpr, Node *rexpr) (strcmp(opname,"~*") == 0 && isalpha(n->val.val.str[pos]))) break; if (n->val.val.str[pos] == '\\') + { pos++; - if (n->val.val.str[pos] == '\0') - break; + if (n->val.val.str[pos] == '\0') + break; + } match_least[match_pos] = n->val.val.str[pos]; match_most[match_pos++] = n->val.val.str[pos]; } @@ -5430,16 +5437,22 @@ static Node *makeIndexable(char *opname, Node *lexpr, Node *rexpr) for (pos = 0; n->val.val.str[pos]; pos++) { - if (n->val.val.str[pos] == '%' && - n->val.val.str[pos+1] != '%') - break; - if(n->val.val.str[pos] == '_') + /* % and _ are wildcard characters in LIKE */ + if (n->val.val.str[pos] == '%' || + n->val.val.str[pos] == '_') break; - if (n->val.val.str[pos] == '\\' || - n->val.val.str[pos+1] == '%') + /* Backslash quotes the next character */ + if (n->val.val.str[pos] == '\\') + { pos++; - if (n->val.val.str[pos] == '\0') - break; + if (n->val.val.str[pos] == '\0') + break; + } + /* + * NOTE: this code used to think that %% meant a literal %, + * but textlike() itself does not think that, and the SQL92 + * spec doesn't say any such thing either. + */ match_least[match_pos] = n->val.val.str[pos]; match_most[match_pos++] = n->val.val.str[pos]; } |