PostgreSQL Reference Manual
Volume 1: SQL Language Reference
for version 8.2.4.
June 2007The PostgreSQL Global Development Group
Actually, PostgreSQL uses the default B-tree
operator class for the expression's data type to determine the sort
data types will be set up so that the
> operators correspond to this sort ordering,
but a user-defined data type's designer could choose to do something
The conversion names follow a standard naming scheme: The
official name of the source encoding with all
non-alphanumeric characters replaced by underscores followed
_to_ followed by the equally processed
destination encoding name. Therefore the names might deviate
from the customary encoding names.
(3) 60 if leap seconds are implemented by the operating system
(4) Essentially, a predicate-locking system prevents phantom reads by restricting what is written, whereas MVCC prevents them by restricting what is read.
Examples in this section are drawn from the regression test database
after doing a
VACUUM ANALYZE, using 8.2 development sources.
You should be able to get similar results if you try the examples yourself,
but your estimated costs and row counts will probably vary slightly
ANALYZE's statistics are random samples rather
than being exact.
You can get the effect of disabling foreign keys by using
--disable-triggers option--but realize that
that eliminates, rather than just postponing, foreign key
validation, and so it is possible to insert bad data if you use it.
|ISBN 0954612027||PostgreSQL Reference Manual - Volume 1 - SQL Language Reference||See the print edition|