Unanswered: how postgres recognize a record uniquely internally
I am using postgres 8.4.
In Oracle each record in a table is recognize by the 'row_id'. Which is maintained by Oracle itself. By the row_id Oracle recognize a record in a table distinctly. Likewise in Postgres, how Postgres recognize a record distinctly. Is it maintaining a 'row_id' like Oracle.
You'd shouldn't need ctid very often, use the pk when ever possible. In older versions of Oracle the rowid was the fastest way to the record and was used a lot. But its recommended to use PK on Oracle now too.