Comparison Operators

Comparison operators are available for all data types and return Boolean values.

All comparison operators are binary operators. Only data types that are the same or can be implicitly converted can be compared using comparison operators.

Table 1 describes comparison operators provided by GaussDB.

**Table 1** Comparison operations
Operator	Description
<	Less than
>	Greater than
<=	Less than or equal to
>=	Greater than or equal to
=	Equal to
<>, !=, or ^=	Not equal to

Comparison operators are available for all relevant data types. All comparison operators are binary operators that returned values of Boolean type. Expressions like 1 < 2 < 3 are invalid. (Because there is no comparison operator to compare a Boolean value with 3.)

Besides, each comparison operator has a corresponding function in the pg_proc system catalog. If the value of proleakproof attribute of the corresponding function is f, the function is not used to prevent data leakage. If a user only has the permission for a system view, but does not have the permission for the corresponding table, the query plan may not be optimal when the user searches the system view.

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