Commit fec8faa0 authored by unknown's avatar unknown
Browse files

InnoDB: Do not get a lock for consistent reads (Bug #3894) 


sql/ha_innodb.cc:
  start_stmt(): Obtain an exclusive lock for other than plain SELECT
parent ea21baa5

sql/ha_innodb.cc

+11 −0
Original line number Diff line number Diff line
@@ -4504,6 +4504,17 @@ ha_innobase::start_stmt( 
	        prepared for an update of a row */

	  

	        prebuilt->select_lock_type = LOCK_X;

	} else {

		/* For other than temporary tables, we obtain

		no lock for consistent read (plain SELECT), and

		an exclusive lock for SELECT ... FOR UPDATE or

		SELECT ... LOCK IN SHARE MODE. */



		prebuilt->select_lock_type =

			thd->lex.sql_command == SQLCOM_SELECT

			&& thd->lex.lock_option == TL_READ

			? LOCK_NONE

			: LOCK_X;

	}

	

	/* Set the MySQL flag to mark that there is an active transaction */