I want to check whether any rows in my column (
TIMESTAMP WITH TIME ZONE) are not stored using UTC. Is there a query I can write to match values that are stored with a TZ offset of 1 or 8 or 11 or (not 0)?
No, there is not. The type name
timestamp with time zone can be misleading. The time zone is not stored at all, it just serves as input / output modifier and all values are stored as UTC internally.