Hello! I've encountered a very strange problem with Postgresql 7.3. I have the following set of queries running in transaction, using libpqxx 2.6.9: ALTER TABLE my_table ADD new_column TEXT UPDATE my_table SET new_column = 'disable' ALTER TABLE my_table ALTER COLUMN new_column SET DEFAULT 'disable' CREATE UNIQUE INDEX my_index ON my_table (old_column) The last query fails with: ERROR: Cannot create unique index. Table contains non-unique values Running the same set of queries manually causes no problems. Moreover, running the last query in a separate transaction works as well. Why is a new column affecting unique index creation on an already existing one? Is there any workaround for this issue? Thank you, Dima Kagan ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org/