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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/