Hello, I'e got a very strange (scary) problem. Look at that : itu_test-# \d ERROR: cache lookup failed for relation 1024 itu_test=# \q [user@varese ~]$ psql -h pisa itu_test itu_test=# \d ERROR: cache lookup failed for relation 1024 itu_test=# select * from zones; zone_id | code | region_id ---------+------+----------- 1 | can | 1 (1 row) itu_test=# \d zones; ERROR: cache lookup failed for relation 1024 itu_test=# drop table zones cascade; NOTICE: drop cascades to constraint fk894f2383638e21c5 on table zones_localized NOTICE: drop cascades to constraint fk2f1483ad638e21c5 on table resources_zones NOTICE: drop cascades to constraint fk6ca02e89638e21c5 on table regulator_zones NOTICE: drop cascades to constraint fkfe5f0292638e21c5 on table regulators DROP TABLE itu_test=# \d ERROR: cache lookup failed for relation 1024 itu_test=# VACUUM ANALYZE; ERROR: could not open segment 1 of relation "pg_class_oid_index" (target block 1702494308): No such file or directory itu_test=# REINDEX DATABASE itu_test; NOTICE: table "pg_class" was reindexed (...) NOTICE: table "pg_language" was reindexed ERROR: could not read block 81235 of relation "pg_largeobject": Input/output error itu_test=# \d ERROR: cache lookup failed for relation 1024 itu_test=# reindex table pg_class; REINDEX itu_test=# VACUUM ANALYZE; WARNING: relation "pg_class" TID 12638/1: OID is invalid (...) WARNING: relation "pg_class" TID 12638/24: OID is invalid ERROR: cannot compare arrays of different element types itu_test=# \d List of relations Schema | Name | Type | Owner --------+------------------------------+----------+---------- public | categories | table | soft_itu (...) public | zones_localized | table | soft_itu (51 rows)