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MySQL 9.2 Reference Manual  / ...  / MySQL Performance Schema  / Performance Schema Table Descriptions  /  Performance Schema User-Defined Variable Tables

29.12.10 Performance Schema User-Defined Variable Tables

The Performance Schema provides auser_variables_by_thread table that exposes user-defined variables. These are variables defined within a specific session and include a@ character preceding the name; seeSection 11.4, “User-Defined Variables”.

Theuser_variables_by_thread table has these columns:

  • THREAD_ID

    The thread identifier of the session in which the variable is defined.

  • VARIABLE_NAME

    The variable name, without the leading@ character.

  • VARIABLE_VALUE

    The variable value.

Theuser_variables_by_thread table has these indexes:

  • Primary key on (THREAD_ID,VARIABLE_NAME)

TRUNCATE TABLE is not permitted for theuser_variables_by_thread table.