LOCALTRANSACTIONS is a pseudo table generated to show information about all transactions currently running in the database. Only transactions that are known to the Transaction Engine (TE) are shown. For a global view of all transactions on all nodes, use SYSTEM.TRANSACTIONS.
The NODEID
column in this table specifies the TE on which this transaction is currently running. This value for a given transaction does not change.
Caution: Client applications should never contain code that accesses SYSTEM
pseudo tables as they are subject to, and furthermore likely to, change from release to release.
Field | Type | Description |
---|---|---|
ID | bigint | A unique identifier for the transaction. |
STATE | string | Active , Committed , RolledBack , Failed , or Purgatory . |
NODEID | integer | The ID of the TE where this transaction is running. |
BLOCKEDBY | bigint | The ID of a transaction that is blocking this transaction. |
STARTEVENT | bigint | The internal event ID that began this transaction. |
ENDEVENT | bigint | The internal event ID that ended this transaction. |
SEQUENCE | bigint | For internal use only. |
ISOLATIONLEVEL | string |
Specifies the transaction isolation level for the connection.
See Supported Transaction Isolation Levels for more information. |
ISUPDATE | boolean | True if there are update events in this transaction. |
DEADLOCKVICTIM | boolean | True if this transaction was a victim of deadlock, and therefore killed. |
COMMITPROTOCOL | string | The commit protocol being used by the transaction. Provided in the same format as used by values of the commit database option. |
QUEUE | string | The name of the internal queue for this transaction. |
SOURCENODE | integer | Same as NODEID . |
XID | bytes | X/Open XA transaction identifier XID structure. Consists of a global transaction format ID, a global transaction ID, and a branch qualifier. For more details on NuoDB XA see JDBC and XA Transactions Using NuoDB. |
PRIORBLOCKEDBY | bigint | The ID of the transaction that was blocking the present transaction before the present transaction was chosen as a victim to resolve the transaction deadlock. |
None
The example below shows all transactions running on the database from the viewpoint of the TE on which these transactions are running. This is the most complete view of information for all transactions currently running on all TEs.
Note: We use SET OUTPUT VERTICAL
to make the output more readable.
SELECT * FROM system.transactions
WHERE sourcenode=nodeid;
==================================== Row #1 ====================================
ID: 677653763
STATE: Active
NODEID: 3
BLOCKEDBY: -1
STARTEVENT: 24368
ENDEVENT: <null>
SEQUENCE: -1
ISOLATIONLEVEL: SERIALIZABLE
ISUPDATE: 0
DEADLOCKVICTIM: 0
COMMITPROTOCOL: remote:1
QUEUE: Active
SOURCENODE: 3
XID: <null>
PRIORBLOCKEDBY: -1
==================================== Row #2 ====================================
ID: 677865476
STATE: Active
NODEID: 4
BLOCKEDBY: -1
STARTEVENT: 29810
ENDEVENT: <null>
SEQUENCE: -1
ISOLATIONLEVEL: SERIALIZABLE
ISUPDATE: 1
DEADLOCKVICTIM: 0
COMMITPROTOCOL: remote:1
QUEUE: Active
SOURCENODE: 4
XID: <null>
PRIORBLOCKEDBY: -1