*** a/src/backend/commands/vacuum.c
--- b/src/backend/commands/vacuum.c
***************
*** 1192,1204 **** vac_truncate_clog(TransactionId frozenXID,
  	AdvanceOldestCommitTsXid(frozenXID);
  
  	/*
- 	 * Truncate CLOG, multixact and CommitTs to the oldest computed value.
- 	 */
- 	TruncateCLOG(frozenXID, oldestxid_datoid);
- 	TruncateCommitTs(frozenXID);
- 	TruncateMultiXact(minMulti, minmulti_datoid);
- 
- 	/*
  	 * Update the wrap limit for GetNewTransactionId and creation of new
  	 * MultiXactIds.  Note: these functions will also signal the postmaster
  	 * for an(other) autovac cycle if needed.   XXX should we avoid possibly
--- 1192,1197 ----