Write locks maintain the reliability of information by preventing
concurrent access to rows or tables by more than one transaction. Transaction blocking and
snapshot versioning manage statements until a lock becomes available. However, deadlock can
occur when a set of transactions arrive at a state where none of them can proceed.
SAP Control Center allows you to view deadlock details, and to specify
how these details are displayed.
Prerequisites
| Database Version |
View Deadlock Privileges |
|---|
| SAP Sybase IQ 15.3 and 15.4 |
You must have DBA authority. |
| SAP Sybase IQ
16.0 |
You must have the MANAGE ANY USER system privilege. |
If you do not have the required pre-requisites, the deadlock details will be
read-only.
Task- In the Perspective Resources view, select the resource, and select .
- In the left pane of the IQ Node Level Monitor view, select
Deadlocks.
- From the list, select the deadlock you want details about.
| Area |
Description |
|---|
| Waiter |
The resource (server) that the proxy table will be created
on. |
| Waiter Connection ID |
The defined remote server containing the remote object to be
represented by the proxy table. |
| Owner Connection ID |
The defined local user that will own the proxy table. |
- View the deadlock details.
| Area |
Description |
|---|
| Snapshot ID |
Identifies the snapshot version managing the transaction. |
| Snapshot Time |
Indicates when the snapshot was created. |
| Object ID |
Identifies the table, materialized view or other object causing
the deadlock. |
| Record ID |
Identifies the record causing the deadlock, if one exists. |
| Table Name |
Indicates the name of the deadlocked table in owner.table
format |
| Is Victim |
A boolean indicator showing whether this connection was the victim
of the deadlock |
| Primary Key |
Indicates the primary key for the deadlocked table. |
| Rollback Operation Count |
The number of times the rollback command has been executed to
resolve the deadlock. |
| SQL Statement |
Displays the SQL statement which caused the deadlock. |
- (Optional) If you have the appropriate authority, select Clear Deadlock
Information to remove all items from the list.
- (Optional) If you have the appropriate authority, select Deadlock
Settings to modify how deadlock details are collected and displayed.
- Specify whether to create a list of deadlocks with the Collect
information check-box.
- Specify whether to include the causal SQL statements in the list of deadlocks
with the SQL statement check-box.