Error Message
/opt/omni/sbin/omnidbcheck

Check Level Mode Status
==========================================================
Database connection -connection OK
Schema consistency -schema_consistency Failed
Datafiles consistency -verify_db_files OK
DCBF(presence and size) -bf OK
DONE!

- extracts from OMNIDBCHECK debug
[299] 2020-06-08 11:19:31.985 ("/lib/cmn/common.c $Rev: 51341 $ $Date:: 2016-01-18 08:41:19":2784)
[299] ===>> (5) CmnRunReadLine {
[299]
[199] [CmnPipeRead] pswait:1
[400] [CmnPipeRead] read:75/4095 pg_dump: symbol lookup error: pg_dump: undefined symbol: PQconnectdbParams

Cause
Another PostgreSQL version has been installed in Cell Manager system .
CM package includes PostgreSQL and it's not expected that another PostgeSQL coexists in the system .

# pg_dump --version
pg_dump (PostgreSQL) 8.4.20

# which pg_dump
/usr/bin/pg_dump

# /opt/omni/idb/bin/pg_dump --version
pg_dump (PostgreSQL) 9.1.9

# rpm -qa |grep postgres
postgresql-libs-8.4.20-5.el6_7.x86_64
postgresql-devel-8.4.20-5.el6_7.x86_64
postgresql-8.4.20-5.el6_7.x86_64

Workaround / Fix
The issue might be able to be avoided by adding /opt/omni/idb/bin to PATH with priority, but it will make another issue because PostgreSQL commands under /usr/bin won't be referred anymore .
Please consider to uninstall PostgreSQL that has been installed apart from DP installation .