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Performance Schema events_statements_history_long Table

MariaDB starting with 10.0

The events_statements_history_long table, along with many other new Performance Schema tables, was added in MariaDB 10.0

The events_statements_history_long table by default contains the ten thousand most recent completed statement events. This number can be adjusted by setting the performance_schema_events_statements_history_long_size system variable when the server starts up.

The table structure is identical to the events_statements_current table structure, and contains the following columns:

Column Description
THREAD_ID Thread associated with the event. Together with EVENT_ID uniquely identifies the row.
EVENT_ID Thread's current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.
END_EVENT_ID NULL when the event starts, set to the thread's current event number at the end of the event.
EVENT_NAME Event instrument name and a NAME from the setup_instruments table
SOURCE Name and line number of the source file containing the instrumented code that produced the event.
TIMER_START Value in picoseconds when the event timing started or NULL if timing is not collected.
TIMER_END Value in picoseconds when the event timing ended, or NULL if timing is not collected.
TIMER_WAIT Value in picoseconds of the event's duration or NULL if timing is not collected.
LOCK_TIME Time in picoseconds spent waiting for locks. The time is calculated in microseconds but stored in picoseconds for compatibility with other timings.
SQL_TEXT The SQL statement, or NULL if the command is not associated with an SQL statement.
DIGEST Statement digest.
DIGEST_TEXT Statement digest text.
CURRENT_SCHEMA Statement's default database for the statement, or NULL if there was none.
OBJECT_SCHEMA Reserved, currently NULL
OBJECT_NAME Reserved, currently NULL
OBJECT_TYPE Reserved, currently NULL
OBJECT_INSTANCE_BEGIN Address in memory of the statement object.
MYSQL_ERRNO Error code. See MariaDB Error Codes for a full list.
RETURNED_SQLSTATE The SQLSTATE value.
MESSAGE_TEXT Statement error message. See MariaDB Error Codes.
ERRORS 0 if SQLSTATE signifies completion (starting with 00) or warning (01), otherwise 1.
WARNINGS Number of warnings from the diagnostics area.
ROWS_AFFECTED Number of rows affected the statement affected.
ROWS_SENT Number of rows returned.
ROWS_EXAMINED Number of rows read during the statement's execution.
CREATED_TMP_DISK_TABLES Number of on-disk temp tables created by the statement.
CREATED_TMP_TABLES Number of temp tables created by the statement.
SELECT_FULL_JOIN Number of joins performed by the statement which did not use an index.
SELECT_FULL_RANGE_JOIN Number of joins performed by the statement which used a range search of the first table.
SELECT_RANGE Number of joins performed by the statement which used a range of the first table.
SELECT_RANGE_CHECK Number of joins without keys performed by the statement that check for key usage after each row.
SELECT_SCAN Number of joins performed by the statement which used a full scan of the first table.
SORT_MERGE_PASSES Number of merge passes by the sort algorithm performed by the statement. If too high, you may need to increase the sort_buffer_size.
SORT_RANGE Number of sorts performed by the statement which used a range.
SORT_ROWS Number of rows sorted by the statement.
SORT_SCAN Number of sorts performed by the statement which used a full table scan.
NO_INDEX_USED 0 if the statement performed a table scan with an index, 1 if without an index.
NO_GOOD_INDEX_USED 0 if a good index was found for the statement, 1 if no good index was found. See the Range checked for each record description in the EXPLAIN article.
NESTING_EVENT_ID Reserved, currently NULL.
NESTING_EVENT_TYPE Reserved, currently NULL.

It is possible to empty this table with a TRUNCATE TABLE statement.

events_statements_current and events_statements_history are related tables.

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https://mariadb.com/kb/en/performance-schema-events_statements_history_long-table/