After Mview Logs Creation, There is A Lot Of 'Dfs Lock Handle' Waits On DML (Doc ID 845886.1)

Last updated on SEPTEMBER 11, 2014

Applies to:

Oracle Database - Enterprise Edition - Version 10.2.0.3 to 10.2.0.4 [Release 10.2]
Information in this document applies to any platform.

Symptoms

After creating materialized view logs on two very active tables, many sessions doing DML on those base tables were showing 'DFS LockHandle' waits.

  1. Trace files, generated by a system state dump, show a reference to a sequence.
    KGL Sequence Object #535: 
  2. A query of dba_objects for object_id 535 determined this is object SYS.CDC_RSID_SEQ$, which is the same sequence used to insert data into some of the mview logs tables :

    INSERT /*+ IDX(0) */ INTO "SBDBA0"."MLOG$_BASETABLE" (dmltype$$,old_new$$, snaptime$$
    ,change_vector$$,sequence$$,m_row$$,"COL1","UID","STATUS" ,"ID","PFUID") VALUES
    (:d,:o,to_date('4000-01-01:00:00:00','YYYY-MM-DD:HH24:MI:SS'),:c
    ,sys.cdc_rsid_seq$.nextval,:m,:1,:2,:3,:4,:5)

Cause

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