SUM_SORT_RANGE: 0 SUM_SORT_ROWS: 0 SUM_SORT_SCAN: 0 SUM_NO_INDEX_USED: 6 SUM_NO_GOOD_INDEX_USED: 0 ... 

Each statement summary table has one or more grouping columns to indicate how the table aggregates events. Event names refer to names of event instruments in the setup_instruments  table: 

• events_statements_summary_by_account_by_event_name  has EVENT_NAME , USER , and HOST columns. Each row summarizes events for a given account (user and host combination) and event name. 

• events_statements_summary_by_digest  has SCHEMA_NAME  and DIGEST  columns. Each row summarizes events per schema and digest value. (The DIGEST_TEXT  column contains the corresponding normalized statement digest text, but is neither a grouping nor a summary column. The QUERY_SAMPLE_TEXT , QUERY_SAMPLE_SEEN , and QUERY_SAMPLE_TIMER_WAIT  columns also are neither grouping nor summary columns; they support statement sampling.) 

The maximum number of rows in the table is autosized at server startup. To set this maximum explicitly, set the performance_schema_digests_size  system variable at server startup. 

• events_statements_summary_by_host_by_event_name  has EVENT_NAME  and HOST  columns. Each row summarizes events for a given host and event name. 

• events_statements_summary_by_program  has OBJECT_TYPE , OBJECT_SCHEMA , and OBJECT_NAME  columns. Each row summarizes events for a given stored program (stored procedure or function, trigger, or event). 

• events_statements_summary_by_thread_by_event_name  has THREAD_ID  and EVENT_NAME columns. Each row summarizes events for a given thread and event name. 

• events_statements_summary_by_user_by_event_name  has EVENT_NAME  and USER  columns. Each row summarizes events for a given user and event name. 

• events_statements_summary_global_by_event_name  has an EVENT_NAME  column. Each row summarizes events for a given event name. 

• prepared_statements_instances  has an OBJECT_INSTANCE_BEGIN  column. Each row summarizes events for a given prepared statement. 

Each statement summary table has these summary columns containing aggregated values (with exceptions as noted): 

## • COUNT_STAR , SUM_TIMER_WAIT , MIN_TIMER_WAIT , AVG_TIMER_WAIT , MAX_TIMER_WAIT 

These columns are analogous to the columns of the same names in the wait event summary tables (see Section 27.12.20.1, “Wait Event Summary Tables” ), except that the statement summary tables aggregate events from events_statements_current  rather than events_waits_current . 

The prepared_statements_instances  table does not have these columns. 

## • SUM_ xxx 

The aggregate of the corresponding xxx  column in the events_statements_current  table. For example, the SUM_LOCK_TIME  and SUM_ERRORS  columns in statement summary tables are the aggregates of the LOCK_TIME  and ERRORS  columns in events_statements_current  table. 

