2499817 - Incorrect insert allowed by SAP IQ results in HG index corruption

After upgrading SAP IQ server to IQ 16 data is getting incorrectly updated, resulting in HG index corruption.
On the tables involved when sp_iqcheckdb 'verify index <HG index>' is executed then you will see the following output :

** Inconsistent Index      owner.table1.ASIQ_IDX_T1335_C2_HG
   Verified Index          owner.table1.ASIQ_IDX_T1335_C2_FP
   FP Indexes Checked                              1                                      
   HG Indexes Checked                              1                                      
** HG Missing Keys                                 85480                                  
** Rows in hg do not match the column ebm          1     

The following conditions need to exist for it to happen:

1. PK-FK condition needs to exist
2. The column should have a compare index

If compare index did not exist then one will get following error and data will not get inserted:

Cannot load/insert/update FK FK_Table2_Table1 row
  7578309 because of RI violation.
  -- (slib/s_ohcidx.cxx 5759)

• SAP IQ 16.0
• SAP IQ 16.1

incorrect result , upgrade , migration , corruption , secondary index , compare index , foreign key relationship , KBA , BC-SYB-IQ , Sybase IQ , Bug Filed