1. Database Reference
  2. Dynamic Performance Views
  3. Dynamic Performance (V$) Views: V$SCHEDULER_IN_MEMORY_TRACE to V$ZONEMAP_USAGE_STATS
  4. V$SHARD_APPLY_READER

10.46 V$SHARD_APPLY_READER

V$SHARD_APPLY_READER displays information about apply reader processes.

Column Datatype Description

SID

NUMBER

Session identifier of the apply reader process

SERIAL#

NUMBER

Session serial number of the apply reader process

APPLY#

NUMBER

Apply process number

An apply process is an Oracle background process, prefixed by ap.

APPLY_NAME

VARCHAR2(128)

Name of the apply process

STATE

VARCHAR2(36)

State of the apply reader:

  • DEQUEUE LCRS

  • IDLE

  • INITIALIZING

  • PAUSED - WAITING FOR DDL TO COMPLETE

  • SCHEDULE TRANSACTIONS

  • SPILLING

TOTAL_LCRS_DEQUEUED

NUMBER

Total number of LCRs read

TOTAL_LCRS_SPILLED

NUMBER

Total number of LCRs spilled

DEQUEUE_TIME

DATE

Last read LCR time

DEQUEUED_LCR_LOG_INDEX

NUMBER

Last read LCR log index

DEQUEUED_LCR_CREATE_TIME

DATE

Last read LCR create time

SGA_USED

NUMBER

Amount of SGA memory (in bytes) used by the apply process since it was last started

ELAPSED_DEQUEUE_TIME

NUMBER

Time elapsed (in hundredths of a second) while dequeuing the last LCR

ELAPSED_SCHEDULE_TIME

NUMBER

Time elapsed (in hundredths of a second) spent scheduling transactions since the apply process was last started

ELAPSED_SPILL_TIME

NUMBER

Time elapsed (in hundredths of a second) while spilling LCRs

LAST_BROWSE_LOG_INDEX

NUMBER

Last browsed LCR log index

OLDEST_LOG_INDEX

NUMBER

Oldest log index

OLDEST_XIDUSN

NUMBER

Transaction ID undo segment number of the oldest transaction

OLDEST_XIDSLT

NUMBER

Transaction ID slot number of the oldest transaction

OLDEST_XIDSQN

NUMBER

Transaction ID sequence number of the oldest transaction

SPILL_LWM_LOG_INDEX

NUMBER

Spill low-watermark log index

OLDEST_TRANSACTION_ID

VARCHAR2(128)

Oldest transaction ID

TOTAL_LCRS_WITH_DEP

NUMBER

Number of LCRs with row-level dependencies since the apply process last started

TOTAL_LCRS_WITH_WMDEP

NUMBER

Number of LCRs with watermark dependencies since the apply process last started

A watermark dependency occurs when an apply process must wait until the apply process's low watermark reaches a particular threshold.

TOTAL_IN_MEMORY_LCRS

NUMBER

Total number of LCRs currently in memory

SGA_ALLOCATED

NUMBER

Total amount of shared memory (in bytes) allocated from the SGA for the apply process since the apply process last started

RU_ID

NUMBER

Replication unit (RU) identifier

DB_ID

NUMBER

Database identifier

TOTAL_ON_DISK_LCRS_READ

NUMBER

Number of LCRs read from disk

LAST_ON_DISK_LCR_LOG_INDEX

NUMBER

Last LCR log index read from disk

STARTUP_TIME

DATE

Apply reader process start time

CON_ID

NUMBER

The ID of the container to which the data pertains. Possible values include:

  • 0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.

  • 1: This value is used for rows containing data that pertain to only the root

  • n: Where n is the applicable container ID for the rows containing data

Note:

This view is available starting with Oracle Database 23ai.