Commit 7fd1f098 authored by unknown's avatar unknown
Browse files

Relaxed locking in INSERT...SELECT, single table UPDATE...SELECT and 

single table DELETE...SELECT clauses when innobase_locks_unsafe_for_binlog
is used and isolation level of the transaction is not serializable. 
InnoDB uses consistent read in these cases for a selected table.
parent e33ef0d9

sql/ha_innodb.cc

+34 −42
Original line number Diff line number Diff line
@@ -5793,8 +5793,27 @@ ha_innobase::store_lock( 
		unexpected if an obsolete consistent read view would be

		used. */



		if (srv_locks_unsafe_for_binlog &&

		    prebuilt->trx->isolation_level != TRX_ISO_SERIALIZABLE &&

		    (lock_type == TL_READ || lock_type == TL_READ_NO_INSERT) &&

		    thd->lex->sql_command != SQLCOM_SELECT &&

		    thd->lex->sql_command != SQLCOM_UPDATE_MULTI &&

		    thd->lex->sql_command != SQLCOM_DELETE_MULTI ) {



			/* In case we have innobase_locks_unsafe_for_binlog

			option set and isolation level of the transaction

			is not set to serializable and MySQL is doing

			INSERT INTO...SELECT without FOR UPDATE or IN

			SHARE MODE we use consistent read for select. 

			Similarly, in case of DELETE...SELECT and

			UPDATE...SELECT when these are not multi table.*/



			prebuilt->select_lock_type = LOCK_NONE;

			prebuilt->stored_select_lock_type = LOCK_NONE;

		} else {

			prebuilt->select_lock_type = LOCK_S;

			prebuilt->stored_select_lock_type = LOCK_S;

		}



	} else if (lock_type != TL_IGNORE) {
@@ -6180,8 +6199,9 @@ innobase_query_is_update(void) 
/***********************************************************************

This function is used to prepare X/Open XA distributed transaction   */



int innobase_xa_prepare(

/*====================*/

int 

innobase_xa_prepare(

/*================*/

			/* out: 0 or error number */

	THD*	thd,	/* in: handle to the MySQL thread of the user

			whose XA transaction should be prepared */
@@ -6244,12 +6264,13 @@ int innobase_xa_prepare( 
/***********************************************************************

This function is used to recover X/Open XA distributed transactions   */



int innobase_xa_recover(

int 

innobase_xa_recover(

/*================*/

				/* out: number of prepared transactions 

				stored in xid_list */

	XID*    xid_list, 	/* in/out: prepared transactions */

	uint	len)		/* in: number of slots in xid_list */

/*====================*/

{

	if (len == 0 || xid_list == NULL) {

		return 0;
@@ -6262,8 +6283,9 @@ int innobase_xa_recover( 
This function is used to commit one X/Open XA distributed transaction

which is in the prepared state */



int innobase_commit_by_xid(

/*=======================*/

int 

innobase_commit_by_xid(

/*===================*/

			/* out: 0 or error number */

	XID*	xid)	/*  in: X/Open XA Transaction Identification */

{
@@ -6284,7 +6306,9 @@ int innobase_commit_by_xid( 
This function is used to rollback one X/Open XA distributed transaction

which is in the prepared state */



int innobase_rollback_by_xid(

int 

innobase_rollback_by_xid(

/*=====================*/

			/* out: 0 or error number */

	XID	*xid)	/* in : X/Open XA Transaction Idenfification */

{
@@ -6299,36 +6323,4 @@ int innobase_rollback_by_xid( 
	}

}



/***********************************************************************

This function is used to test commit/rollback of XA transactions */



int innobase_xa_end(

/*================*/

	THD*	thd)	/* in: MySQL thread handle of the user for whom

			transactions should be recovered */

{

        DBUG_ENTER("innobase_xa_end");



	XID trx_list[100];

	int trx_num, trx_num_max = 100;

	int i;

	XID xid;



	while((trx_num = innobase_xa_recover(trx_list, trx_num_max))) {



		for(i=0;i < trx_num; i++) {

			xid = trx_list[i];



			if ( i % 2) {

				innobase_commit_by_xid(&xid);

			} else {

				innobase_rollback_by_xid(&xid);

			}

		}

	}



	free(trx_list);



	DBUG_RETURN(0);

}

#endif /* HAVE_INNOBASE_DB */