The session_account_connect_attrs  table has these indexes: 

•Primary key on ( PROCESSLIST_ID , ATTR_NAME ) 

TRUNCATE TABLE  is not permitted for the session_account_connect_attrs  table. 

## 27.12.9.2 The session_connect_attrs Table 

Application programs can provide key-value connection attributes to be passed to the server at connect time. For descriptions of common attributes, see Section 27.12.9, “Performance Schema Connection Attribute Tables” . 

The session_connect_attrs  table contains connection attributes for all sessions. To see connection attributes only for the current session, and other sessions associated with the session account, use the session_account_connect_attrs  table. 

The session_connect_attrs  table has these columns: 

• PROCESSLIST_ID 

The connection identifier for the session. 

• ATTR_NAME 

The attribute name. 

• ATTR_VALUE 

The attribute value. 

• ORDINAL_POSITION 

The order in which the attribute was added to the set of connection attributes. 

The session_connect_attrs  table has these indexes: 

•Primary key on ( PROCESSLIST_ID , ATTR_NAME ) 

TRUNCATE TABLE  is not permitted for the session_connect_attrs  table. 

## 27.12.10 Performance Schema User-Defined Variable Tables 

The Performance Schema provides a user_variables_by_thread  table that exposes user-defined variables. These are variables defined within a specific session and include a @  character preceding the name; see Section 9.4, “User-Defined Variables” . 

The user_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 

