27.12.20.8.1 The table_io_waits_summary_by_table Table

The table_io_waits_summary_by_table table aggregates all table I/O wait events, as generated by the wait/io/table/sql/handler instrument. The grouping is by table.

The table_io_waits_summary_by_table table has these grouping columns to indicate how the table aggregates events: OBJECT_TYPE, OBJECT_SCHEMA, and OBJECT_NAME. These columns have the same meaning as in the events_waits_current table. They identify the table to which the row applies.

table_io_waits_summary_by_table has the following summary columns containing aggregated values. As indicated in the column descriptions, some columns are more general and have values that are the same as the sum of the values of more fine-grained columns. For example, columns that aggregate all writes hold the sum of the corresponding columns that aggregate inserts, updates, and deletes. In this way, aggregations at higher levels are available directly without the need for user-defined views that sum lower-level columns.

The table_io_waits_summary_by_table table has these indexes:

TRUNCATE TABLE is permitted for table I/O summary tables. It resets the summary columns to zero rather than removing rows. Truncating this table also truncates the table_io_waits_summary_by_index_usage table.