Purpose
The BLOCKERS command displays currently blocked transactions and the corresponding blocking transactions with granted lock requests.
Syntax
- ProcId
- The virtual processor number of the parsing engine processor handling the transaction.
- Uniq1
- A value that is normally specified as four hexadecimal digits.
- Uniq2
- A value that is normally specified as four hexadecimal digits.
- ALL
- That all blocked transactions and their corresponding blocker transactions will be considered.
- LIMIT
- The number of blocker transactions to consider for a blocked transaction.
- NUMBER
- The desired limiting value.
- NONE
- That all blocker transactions for a blocked transaction are considered.
Usage Notes
A transaction is an internal database concept. A transaction can have more than one blocking transaction. For example, a transaction can have five lock requests, and five transactions can block those same lock requests. In other words, if you have five tables, then conceivably, five other transactions can have the locks on those same five tables.
The following table shows the components of BLOCKERS command output.
Component.... | Includes the... |
---|---|
Number of Blocked Trans displayed | total number of both blocked and blocker transactions. |
Blocked Trans | number of the blocked transaction and the following information:
|
Blocker Trans | number of blocking transactions and the following information:
|
In the following examples RPT1 is a row-partitioned table, and NOTRPT2 is a non-partitioned table.
Examples: BLOCKERS command
-> Please enter your selection from the list: blockers - The following amps are available: 0 1 2 3 -> Which amp(s) do you want to request on (S=Sampling/A=all/C=cancel/Q=quit): 1 ---------------- AMP 1 REPORTS 2 LOCK ENTRIES ------------- Number of Blocked Trans displayed : 2 ========================================= Blocked Trans : 30719 00015E1C Number of blockers displays : 1 Number of blockers exists : 1 Blocker Trans : 30719 00015DCA lock mode : Write lock status : Granted lock objectType : Row lock objectID : DBID : 00000402 : DBNAME : EXAMPLE : TableID : 00000AA0,0400 : TableName : NOTRPT2 : RowHash1 : 79B69E37 : RowHash2 : 00000000 Blocked Trans : 30719 00015E1B Number of blockers displays : 1 Number of blockers exists : 1 Blocker Trans : 30719 00015DCA lock mode : Write lock status : Granted lock objectType : RowRange lock PLLKind : RowKey lock objectID : DBID : 00000402 : DBNAME : EXAMPLE : TableID : 00000A9D,0400 : TableName : RPT1 : Partition1: 0003 : RowHash1 : 79B69E37 : Partition2: 0003 : RowHash2 : 79B69E37
-> Please enter your selection from the list: blockers tran 30719. 0001 5e1c - The following amps are available: 0 1 2 3 -> Which amp(s) do you want to request on (S=Sampling/A=all/C=cancel/Q=quit): 1 ---------------- AMP 1 REPORTS 1 LOCK ENTRIES ------------- Number of Blocked Trans displayed : 1 ========================================= Blocked Trans : 30719 00015E1C Number of blockers displays : 1 Number of blockers exists : 1 Blocker Trans : 30719 00015DCA lock mode : Write lock status : Granted lock objectType : Row lock objectID : DBID : 00000402 : DBNAME : EXAMPLE : TableID : 00000AA0,0400 : TableName : NOTRPT2 : RowHash1 : 79B69E37 : RowHash2 : 00000000
-> Please enter your selection from the list: blockers tran 30719. 0001 5e1b - The following amps are available: 0 1 2 3 -> Which amp(s) do you want to request on (S=Sampling/A=all/C=cancel/Q=quit): 1 ---------------- AMP 1 REPORTS 1 LOCK ENTRIES ------------- Number of Blocked Trans displayed : 1 ========================================= Blocked Trans : 30719 00015E1B Number of blockers displays : 1 Number of blockers exists : 1 Blocker Trans : 30719 00015DCA lock mode : Write lock status : Granted lock objectType : RowRange lock PLLKind : RowKey lock objectID : DBID : 00000402 : DBNAME : EXAMPLE : TableID : 00000A9D,0400 : TableName : RPT1 : Partition1: 0003 : RowHash1 : 79B69E37 : Partition2: 0003 : RowHash2 : 79B69E37