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

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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.
Backported from 5.0.x.
This commit is contained in:
jan@hundin.mysql.fi 2005-02-08 09:36:36 +02:00
parent 9a1e257087
commit fcfc1d8f29
1 changed files with 21 additions and 2 deletions
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23
sql/ha_innodb.cc
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@ -5282,8 +5282,27 @@ ha_innobase::store_lock(
are not simple SELECTs; note that select_lock_type in this
case may get strengthened in ::external_lock() to LOCK_X. */
prebuilt->select_lock_type = LOCK_S;
prebuilt->stored_select_lock_type = LOCK_S;
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) {