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| author | unknown <timour@askmonty.org> | 2012-03-11 14:39:20 +0200 |
|---|---|---|
| committer | unknown <timour@askmonty.org> | 2012-03-11 14:39:20 +0200 |
| commit | 8aebd44e0ea9c4ae6f573f1ece27b276452122b8 (patch) | |
| tree | e2907ea46e4680c18b85dace99b5ea00d5735043 /sql/sql_yacc.yy | |
| parent | f92cfdb8a9ff7f8287239c39ce4735789a23e3df (diff) | |
| download | mariadb-git-8aebd44e0ea9c4ae6f573f1ece27b276452122b8.tar.gz | |
Implementation of MDEV-28 LIMIT ROWS EXAMINED
https://mariadb.atlassian.net/browse/MDEV-28
This task implements a new clause LIMIT ROWS EXAMINED <num>
as an extention to the ANSI LIMIT clause. This extension
allows to limit the number of rows and/or keys a query
would access (read and/or write) during query execution.
Diffstat (limited to 'sql/sql_yacc.yy')
| -rw-r--r-- | sql/sql_yacc.yy | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy index 084314ff23f..6e383fedf71 100644 --- a/sql/sql_yacc.yy +++ b/sql/sql_yacc.yy @@ -865,6 +865,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize); %token EVENTS_SYM %token EVENT_SYM %token EVERY_SYM /* SQL-2003-N */ +%token EXAMINED_SYM %token EXECUTE_SYM /* SQL-2003-R */ %token EXISTS /* SQL-2003-R */ %token EXIT_SYM @@ -9620,6 +9621,7 @@ opt_limit_clause_init: SELECT_LEX *sel= lex->current_select; sel->offset_limit= 0; sel->select_limit= 0; + lex->limit_rows_examined= 0; } | limit_clause {} ; @@ -9631,6 +9633,8 @@ opt_limit_clause: limit_clause: LIMIT limit_options {} + | LIMIT limit_options ROWS_SYM EXAMINED_SYM limit_rows_option {} + | LIMIT ROWS_SYM EXAMINED_SYM limit_rows_option {} ; limit_options: @@ -9682,6 +9686,13 @@ limit_option: } ; +limit_rows_option: + limit_option + { + LEX *lex=Lex; + lex->limit_rows_examined= $1; + } + delete_limit_clause: /* empty */ { @@ -9694,6 +9705,8 @@ delete_limit_clause: sel->select_limit= $2; sel->explicit_limit= 1; } + | LIMIT ROWS_SYM EXAMINED_SYM { my_parse_error(ER(ER_SYNTAX_ERROR)); MYSQL_YYABORT; } + | LIMIT limit_option ROWS_SYM EXAMINED_SYM { my_parse_error(ER(ER_SYNTAX_ERROR)); MYSQL_YYABORT; } ; int_num: @@ -12131,6 +12144,7 @@ keyword: | DO_SYM {} | END {} | EXECUTE_SYM {} + | EXAMINED_SYM {} | FLUSH_SYM {} | HANDLER_SYM {} | HELP_SYM {} @@ -13011,6 +13025,7 @@ handler: MYSQL_YYABORT; lex->current_select->select_limit= one; lex->current_select->offset_limit= 0; + lex->limit_rows_examined= 0; if (!lex->current_select->add_table_to_list(lex->thd, $2, 0, 0)) MYSQL_YYABORT; } |