Notes on v$transaction
The information here contains the view description from the Oracle9i documentation
Earlier versions of Oracle may not include all columns.
The v$transaction view lists the active transactions in the system.
Column Datatype Description
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ADDR RAW(4) Address of transaction state object
XIDUSN NUMBER Undo segment number
XIDSLOT NUMBER Slot number
XIDSQN NUMBER Sequence number
UBAFIL NUMBER Undo block address (UBA) filenum
UBABLK NUMBER UBA block number
UBASQN NUMBER UBA sequence number
UBAREC NUMBER UBA record number
STATUS VARCHAR2(16) Status
START_TIME VARCHAR2(20) Start time (wall clock)
START_SCNB NUMBER Start system change number (SCN) base
START_SCNW NUMBER Start SCN wrap
START_UEXT NUMBER Start extent number
START_UBAFIL NUMBER Start UBA file number
START_UBABLK NUMBER Start UBA block number
START_UBASQN NUMBER Start UBA sequence number
START_UBAREC NUMBER Start UBA record number
SES_ADDR RAW(4) User session object address
FLAG NUMBER Flag
SPACE VARCHAR2(3) YES if a space transaction
RECURSIVE VARCHAR2(3) YES if a recursive transaction
NOUNDO VARCHAR2(3) YES if a no undo transaction
PTX VARCHAR 2(3) YES if parallel transaction
NAME VARCHAR2(256) Name of a named transaction
PRV_XIDUSN NUMBER Previous transaction undo segment number
PRV_XIDSLT NUMBER Previous transaction slot number
PRV_XIDSQN NUMBER Previous transaction sequence number
PTX_XIDUSN NUMBER Rollback segment number of the parent XID
PTX_XIDSLT NUMBER Slot number of the parent XID
PTX_XIDSQN NUMBER Sequence number of the parent XID
DSCN-B NUMBER Dependent SCN base
DSCN-W NUMBER Dependent SCN wrap
USED_UBLK NUMBER Number of undo blocks used
USED_UREC NUMBER Number of undo records used
LOG_IO NUMBER Logical I/O
PHY_IO NUMBER Physical I/O
CR_GET NUMBER Consistent gets
CR_CHANGE NUMBER Consistent changes
Comments on a few of the columns:
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XIDUSN Rollback Segment ID } Transaction ID is
XIDSLOT Slot in RBS TX table } USN.SLOT.SQN or
XIDSQN Wrap of the entry } TX-USNxSLOT-SQNxxxxx
UBAFIL File for last undo entry } Tail end of UNDO for
UBABLK Block for last undo entry } this transaction
UBASQN Sequence no of last entry }
UBAREC Record no in the block }