2634828 - UPDATE raises Error Msg 644: Index row entry for data row id ... is missing from index page. SAP ASE

• A reoccurring 644 error (every 7 to 14 days) in the last several months on a datarows, 8-way roundrobin partitioned  table:

Msg 644, Level 21, State 5:
Server '<servername>', Line 1:
Index row entry for data row id (1629415183, 18) is missing from index page 854236361 of index id 3 of table '<tablename>' in database '<dbname>'. Xactid is (1571161710,18). Drop and re-create the index.

• A failing UPDATE statement:

update <tablename> set pdate='2/20/1965' from <tablename> (index idx1) where xc=1234567 and id=123 and pdate='1/4/2018' and oid=345 and lamt =0.00

• There were no specific changes/updates to ASE to coincide with the problem. 
• The error has so far occurred on the same data page and rowid and always on the same index id (3) but not the same index page since the index gets rebuilt each time. 
• Rebuilding the index is not a permanent correction.

SAP Adaptive Server Enterprise (ASE) 16.0 SP02 PL03

rebuild, repeating, CR814685, CR#814685, 814685 , KBA , BC-SYB-ASE , Sybase ASE Database Platform (non Business Suite) , Bug Filed