PRIMARY KEY Indexes.

pgsqlPostgres automatically creates a unique index to assure data integrity
(see CREATE INDEX statement).

The online docs at
http://www.postgresql.org/idocs/index.php?sql-createtable.html state the
following:

" Postgres automatically creates a unique index to assure data integrity
(see CREATE INDEX statement). "  ... when PRIMARY KEY is specified within a
CREATE TABLE statement.

My questions:

1) Are these indexes at all visible to a tool like PGAdmin?  How are they
named?

2) If FORIGN KEY constraints were present on tables, I assume a lookup is
done at time of INSERT to ensure the referenced value can be found.  Would
such a lookup and the index used be seen in the EXPLAIN or EXPLAIN VERBOSE
output of an INSERT?

For the record:

OS is RedHat Linux 2.2.19 #8 SMP Fri Sep 21 10:04:24 CDT
Postgres is  PostgreSQL 7.1.2 on i686-pc-linux-gnu, compiled by GCC 2.96






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