5.2.3.2. Dynamic System Variables
Many server system variables are dynamic and can be set at
runtime using SET GLOBAL or SET
SESSION. You can also obtain their values using
SELECT. See
Section 5.2.3, “Using System Variables”.
The following table shows the full list of all dynamic
system variables. The last column indicates for each
variable whether GLOBAL or
SESSION (or both) apply. The table also
lists session options that can be set with the
SET statement.
Section 13.5.3, “SET Syntax”, discusses these options.
Variables that have a type of “string” take a
string value. Variables that have a type of
“numeric” take a numeric value. Variables that
have a type of “boolean” can be set to 0, 1,
ON or OFF. (If you set
them on the command line or in an option file, use the
numeric values.) Variables that are marked as
“enumeration” normally should be set to one of
the available values for the variable, but can also be set
to the number that corresponds to the desired enumeration
value. For enumerated system variables, the first
enumeration value corresponds to 0. This differs from
ENUM columns, for which the first
enumeration value corresponds to 1.
