The value of the
variable affects the information available from the tables
described here. For details, see the description of that
variable in Section 5.1.7, “Server System Variables”.
Information available from the tables described here is also
available from the Performance Schema. The
INFORMATION_SCHEMA tables are deprecated in
preference to the Performance Schema tables and are removed in
MySQL 8.0. For advice on migrating away from the
INFORMATION_SCHEMA tables to the Performance
Schema tables, see
Section 25.20, “Migrating to Performance Schema System and Status Variable Tables”.
SESSION_VARIABLES tables provide
information about server status variables. Their contents
correspond to the information produced by the
VARIABLES statements (see
Section 22.214.171.124, “SHOW VARIABLES Statement”).
VARIABLE_VALUEcolumn for each of these tables is defined as
VARCHAR(1024). For variables with very long values that are not completely displayed, use
SELECTas a workaround. For example: