Thanks for the advice. I re-indexed and reloaded a pg_dumpall into a spare server - no errors. Will run pg_catcheck asap. regards, Andy Andy Halsall <andyh@xxxxxxxxxx> writes: > db=# select * from xxxxx where col_a = 4675635; > col_a | col_b | col_c | col_d | col_e | last_modified > --------+-------------+-----------------+-----------+---------------+--------------- > | | | | | > (1 row) > Row 4675635 is very odd - NULL columns and at the same time retrievable by a value in col_a. Doesn't seem particularly surprising if col_a is indexed. That query would choose an indexscan plan, which would normally not bother to re-verify the index condition against heap tuples found via the index. If you're continuing to use this damaged database, it might be a good idea to try to REINDEX all your indexes. That'd be particularly useful for primary/unique indexes, since if corruption has led to any apparent duplicate rows, the reindex would fail and complain. But in any case it'd clean up heap-vs-index inconsistencies like the above, as well as repairing any cases where the corruption was in an index rather than heap. Another test I'd strongly recommend is to see if you can pg_dumpall and reload into a spare server. That might catch forms of data corruption that reindexing would not, such as violated CHECK constraints. regards, tom lane