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

• events_statements_summary_by_digest hasSCHEMA_NAME andDIGEST columns. Each row summarizes events per schema and digest value. (TheDIGEST_TEXT column contains the corresponding normalized statement digest text, but is neither a grouping nor a summary column. TheQUERY_SAMPLE_TEXT,QUERY_SAMPLE_SEEN, andQUERY_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 theperformance_schema_digests_size system variable at server startup.

• events_statements_summary_by_host_by_event_name hasEVENT_NAME andHOST columns. Each row summarizes events for a given host and event name.

• events_statements_summary_by_program hasOBJECT_TYPE,OBJECT_SCHEMA, andOBJECT_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 hasTHREAD_ID andEVENT_NAME columns. Each row summarizes events for a given thread and event name.

• events_statements_summary_by_user_by_event_name hasEVENT_NAME andUSER columns. Each row summarizes events for a given user and event name.

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

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

• 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 (seeSection 29.12.20.1, “Wait Event Summary Tables”), except that the statement summary tables aggregate events fromevents_statements_current rather thanevents_waits_current.

  Theprepared_statements_instances table does not have these columns.

• SUM_xxx

  The aggregate of the correspondingxxx column in theevents_statements_current table. For example, theSUM_LOCK_TIME andSUM_ERRORS columns in statement summary tables are the aggregates of theLOCK_TIME andERRORS columns inevents_statements_current table.

• MAX_CONTROLLED_MEMORY

  Reports the maximum amount of controlled memory used by a statement during execution.

• MAX_TOTAL_MEMORY

  Reports the maximum amount of memory used by a statement during execution.

• COUNT_SECONDARY

  The number of times a query was processed on theSECONDARY engine. For use with MySQL HeatWave Service and MySQL HeatWave, where thePRIMARY engine isInnoDB and theSECONDARY engine is MySQL HeatWave (RAPID). For MySQL Community Edition Server, MySQL Enterprise Edition Server (on-premise), and MySQL HeatWave Service without MySQL HeatWave, queries are always processed on thePRIMARY engine, which means the value is always 0 on these MySQL Servers.

• FIRST_SEEN,LAST_SEEN

  Timestamps indicating when statements with the given digest value were first seen and most recently seen.

• QUANTILE_95: The 95th percentile of the statement latency, in picoseconds. This percentile is a high estimate, computed from the histogram data collected. In other words, for a given digest, 95% of the statements measured have a latency lower thanQUANTILE_95.

  For access to the histogram data, use the tables described inSection 29.12.20.4, “Statement Histogram Summary Tables”.

• QUANTILE_99: Similar toQUANTILE_95, but for the 99th percentile.

• QUANTILE_999: Similar toQUANTILE_95, but for the 99.9th percentile.

• QUERY_SAMPLE_TEXT

  A sample SQL statement that produces the digest value in the row. This column enables applications to access, for a given digest value, a statement actually seen by the server that produces that digest. One use for this might be to runEXPLAIN on the statement to examine the execution plan for a representative statement associated with a frequently occurring digest.

  When theQUERY_SAMPLE_TEXT column is assigned a value, theQUERY_SAMPLE_SEEN andQUERY_SAMPLE_TIMER_WAIT columns are assigned values as well.

  The maximum space available for statement display is 1024 bytes by default. To change this value, set theperformance_schema_max_sql_text_length system variable at server startup. (Changing this value affects columns in other Performance Schema tables as well. SeeSection 29.10, “Performance Schema Statement Digests and Sampling”.)

  For information about statement sampling, seeSection 29.10, “Performance Schema Statement Digests and Sampling”.

• QUERY_SAMPLE_SEEN

  A timestamp indicating when the statement in theQUERY_SAMPLE_TEXT column was seen.

• QUERY_SAMPLE_TIMER_WAIT

  The wait time for the sample statement in theQUERY_SAMPLE_TEXT column.

• COUNT_STATEMENTS,SUM_STATEMENTS_WAIT,MIN_STATEMENTS_WAIT,AVG_STATEMENTS_WAIT,MAX_STATEMENTS_WAIT

  Statistics about nested statements invoked during stored program execution.

• COUNT_EXECUTE,SUM_TIMER_EXECUTE,MIN_TIMER_EXECUTE,AVG_TIMER_EXECUTE,MAX_TIMER_EXECUTE

  Aggregated statistics for executions of the prepared statement.

• events_transactions_summary_by_account_by_event_name:

  • Primary key on (USER,HOST,EVENT_NAME)

• events_statements_summary_by_digest:

  • Primary key on (SCHEMA_NAME,DIGEST)

• events_transactions_summary_by_host_by_event_name:

  • Primary key on (HOST,EVENT_NAME)

• events_statements_summary_by_program:

  • Primary key on (OBJECT_TYPE,OBJECT_SCHEMA,OBJECT_NAME)

• events_statements_summary_by_thread_by_event_name:

  • Primary key on (THREAD_ID,EVENT_NAME)

• events_transactions_summary_by_user_by_event_name:

  • Primary key on (USER,EVENT_NAME)

• events_statements_summary_global_by_event_name:

  • Primary key on (EVENT_NAME)

• Forevents_statements_summary_by_digest, it removes the rows.

• For other summary tables not aggregated by account, host, or user, truncation resets the summary columns to zero rather than removing rows.

• For other summary tables aggregated by account, host, or user, truncation removes rows for accounts, hosts, or users with no connections, and resets the summary columns to zero for the remaining rows.

If thestatements_digest consumer is enabled, aggregation intoevents_statements_summary_by_digest occurs as follows when a statement completes. Aggregation is based on theDIGEST value computed for the statement.

The row withDIGEST =NULL is maintained because Performance Schema tables have a maximum size due to memory constraints. TheDIGEST =NULL row permits digests that do not match other rows to be counted even if the summary table is full, using a common“other” bucket. This row helps you estimate whether the digest summary is representative:

For stored program types for which instrumentation is enabled in thesetup_objects table,events_statements_summary_by_program maintains statistics for stored programs as follows:

See alsoSection 29.4.3, “Event Pre-Filtering”.