1848603 - DSYS_PHHEAD_ECD2 index error during upgrade

Symptom 1:

During an upgrade to any ECC 6.0 release (SR, EHP or SP on a ECC 6.0 environment), the following error is raised during TABIM_UPG phase:

2EETW000 Update and insert sequence failed due to conflicting unique indexes on table DSYS_PHHEAD_ECD2 (please read OSS note 626915 for details)

However OSS note 626915 provides general guidance and does not contain information about this specific error.

Symptom 2:

The same error appears during an upgrade using Do DMO in phase TABIM_SHADOW_UPG2.

Software Update Manager(SUM), NetWeaver AS ABAP, ECC 6.0

DSYS_PHHEAD_ECD2, upgrade, TABIM_UPG, update, insert sequence, unique index, indexes, conflicting unique indexes, non-unique, SE11, DSYS_PHHEAD_ECD2~PHI, TABIM_SHADOW_UPG2, unlocksys, unlock_eu, locksys, lock_eu, MAIN_NEWBAS, MAIN_NEWBAS/TABIM_UPG, TABIMUPG.LOG, TABIMUPG.ELG,MAIN_NEWBAS/TABIM_UPG , KBA , BC-UPG-TLS-TLA , Upgrade tools for ABAP , BC-CTS-TLS , Transport Tools , PY-XX-FO-HRD , HR Documentation , Problem