How are parallel inserts cause deadlock on DB2?
Parallel inserts cause deadlock on DB2. The scenario is the following: The application attempts to insert into the same table from two parallel threads making 4000 insertions in each thread (separate transaction per thread). It causes the DB always to fail with the following exception:
Why does SQL Server deadlock on DELETE statement?
SQL Server knows ecid 0 and ecid 2 are threads of the same parent process. Unfortunately, step 2 gets in the way of this, and a deadlock results. That said, you shouldn’t really care much about why the deadlock occurs, the important question is how do you avoid it. The answer is to provide an efficient access path for the DELETE.
What are some examples of deadlocks in DDL?
For example, DROP TABLE statements can result in a large number of catalog updates as rows might have to be deleted for the table indexes, primary keys, check constraints, and so on, in addition to the table itself. If other DDL operations are dropping or creating objects, there can be lock conflicts and even occasional deadlocks.
How to avoid a deadlock on a connection?
Consider the following options: Each application connection should process its own set of rows to avoid lock waits.
What causes dB to fail on two parallel threads?
The scenario is the following: The application attempts to insert into the same table from two parallel threads making 4000 insertions in each thread (separate transaction per thread). It causes the DB always to fail with the following exception: com.ibm.db2.jcc.a.pn: The current transaction has been rolled back because of a deadlock or timeout.
Why does DB2 not automatically adapt to increasing workload?
Thus DB2 cannot automatically adapt to increasing workload efficiently. Also DB instance needs to be restarted when this parameter is changed. Often commits also mean that there should be a way to roll back all previous commits if something goes wrong at certain point of time.
What should be the size of locklists in DB2?
One need to know in advance what should be the size of locklists which needs to be increased with the growing number of insertions. Thus DB2 cannot automatically adapt to increasing workload efficiently. Also DB instance needs to be restarted when this parameter is changed.
Where does sqlcode-911 DB2 database deadlock occur?
DB2 database deadlocks and SQLCODE -911 occur in the PersistentLockManager calls. The error indicates that a deadlock occurred in the DB2 database server. Following is the deadlock data that is captured from the DB2 database.
What to do when you have a deadlock on a table?
Procedure Use the following steps to diagnose the cause of the unacceptable deadlock problem and to apply a remedy: Obtain information from the lock event monitor or administration notification log about all tables where agents are experiencing deadlocks.