Streams Apply applies transactions sequentialy when objects do not exists on target site (Doc ID 1124823.1)

Last updated on MAY 11, 2017

Applies to:

Oracle Database - Enterprise Edition - Version 9.2.0.1 to 11.2.0.1.0 [Release 9.2 to 11.2]
Information in this document applies to any platform.

Symptoms

Latency on your Streams environment is growing and you have observed that your apply servers are applying sequentially though apply parallelism has been set. When checking v$streams_apply_server, only one process is on EXECUTE TRANSACTION state, meanwhile others are waiting on 'WAIT DEPENDENCY'



Note that the processes on WAIT DEPENDENCY state are waiting for transaction id 0.0.0.

select SID, STATE, XIDUSN||'.'||XIDSLT||'.'||XIDSQN TX_ID, COMMITSCN,
DEP_XIDUSN||'.'||DEP_XIDSLT||'.'||DEP_XIDSQN DEP_TX_ID, DEP_COMMITSCN from v$streams_apply_server;

SID STATE TX_ID COMMITSCN DEP_TX_ID
DEP_COMMITSCN
----- -------------------- ---------------- -------------- ----------------
--------------
142 WAIT DEPENDENCY 2.30.10994 8175202082187 0.0.0
8175202082185
143 WAIT DEPENDENCY 3.41.10713 8175202082185 0.0.0
8175202082183
148 EXECUTE TRANSACTION 1.14.8303 8175202082181 0.0.0
8175202082179
158 WAIT DEPENDENCY 8.18.11057 8175202082183 0.0.0
8175202082181

Changes

It is not expected dependency between the transactions.

The streams processes have a transformation defined because not all the objects (schemas) existing in source site do exists on <target site.

The size of transactions is not big (=< 999 lcrs/tx).
Remember that when apply have to manage transactions with more than 999 lcrs/tx it forces to apply sequentially, although dependent transaction is not 0.0.0.

Cause

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