Getting Started with PostgreSQL - PostgreSQL Developer's Guide - page 12

• timestamp [(p)][without time zone] : This is used to store the date and
time without a time zone.
• timestamp [(p)] with time zone : This is used to store date and time with
a time zone.
• time , timestamp , and interval : These data types accept an optional precision
value p that speciies the number of fractional digits retained in the seconds
ield. By default, there is no explicit bound on precision. The allowed range of
p is from 0 to 6 for the timestamp and interval types.
• Tsquery : This is used to store a text search query.
• tsvector : This is used to store a text search document.
• txid_snapshot : This is used to store the user-level transaction ID snapshots.
• uuid : This is used to store universally unique identiiers.
• xml : This data type is served as storage for XML data.

PostgreSQL's operators and usage
As PostgreSQL has multiple operators, we will explain all of them in detail in
this section.

Logical operators
Logical operators are available in PostgreSQL, and these are:

• AND
• OR
• NOT

In PostgreSQL, the values of true, false, and null are used as the valued logic
system. For more detail, see the following truth table that shows how data types
a and b can result in different values when combined with the different AND and OR
logical operators:

a b a AND b a OR b

TRUE TRUE TRUE TRUE

TRUE FALSE FALSE TRUE

TRUE NULL NULL TRUE

FALSE FALSE FALSE FALSE

FALSE NULL FALSE NULL

NULL NULL NULL NULL