Inconsistent SQL

Hi 7.2uc3 on Seqent Dynix/Ptx 4.4.1 Table with 8 million + rows, 5 indexes One of five indexes is non unique. sql includes a sub-select on three fields including date > '1998-08-09' result : no rows returned change it to date > '1998-08-10' result : rows we wanted returned Data is transaction data from years ago up to 1999 data. Fixed by re-indexing - then it happens again weeks later, different date. sqlexplain shows that when reindexed Informix uses index b then index a in the query - successfully pre re-indexing sqlexplain shows that it uses index a then b - unsuccessfully. Any ideas?

No ideas, but if misery loves company, consider yourself not alone. I've seen the same think happen with other medium to large tables and we're on a 7.22 release for AIX. I've tried to diagnose by: oncheck - no index or table errors ever were shown update statistics - several different levels, no change But your're correct, rebuild the index and the records are there. Go figure...