1 – RUJ file writes field
This field gives the number of write-I/Os (queued I/O requests) issued to the database recovery-unit journal (.ruj) files. This operation writes before-image records to the .ruj file in case a verb or transaction must be rolled back. Before-images must be written to the RUJ file before the corresponding database page can be written back to the database.
2 – ____data_field_
This field displays the total number of synchronous write I/O operations containing modified database data.
3 – ____control_field_
This field displays the total number of synchronous write I/O operations containing control (header) information.
4 – ____file_extend_field_
This field displays the total number of times the recovery-unit journal files have been extended.
5 – records_written_field
This field displays the number of journal records written to the recovery-unit journal (.ruj) file.
6 – RUJ file reads field
This field gives the number of read-I/Os (queued I/O requests) issued to the database recovery-unit journal (.ruj) files. This operation reads before-image records from the .ruj file to roll back a verb or a transaction.
7 – blocks_written_field
This field gives the number of disk blocks written to the recovery-unit journal file. Because many disk blocks may be written with a single write-I/O, this number may be larger than the number of .ruj file writes. In addition, the same disk block can be written more than once, because it might not have been completely full the first time it was written.
8 – _______read_field_
This field displays the total number of 512-byte blocks that have been read from the .ruj files on this node.
9 – cache_overflows_field
This field displays the number of times the recovery-unit data cache has overflowed, causing a premature synchronous write I/O operation. Overflowing the data cache indicates update-intensive transactions.
10 – DBKEY cache hits field
This field gives the number of times the same DBKEY (row) was modified within the same transaction and found in the DBKEY cache.
11 – ______overflows_field_
This field gives the number of times the DBKEY cache ran out of space and new space had to be allocated.