Performance Schema Summary Tables 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: 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. Each statement summary table has these summary columns containing aggregated values (with exceptions as noted): 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. 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. • COUNT_STAR ,  SUM_TIMER_WAIT ,  MIN_TIMER_WAIT ,  AVG_TIMER_WAIT ,  MAX_TIMER_WAIT • SUM_ xxx • 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.) • 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. 5055 SUM_SORT_RANGE: 0 SUM_SORT_ROWS: 0 SUM_SORT_SCAN: 0 SUM_NO_INDEX_USED: 6 SUM_NO_GOOD_INDEX_USED: 0 ...