一些大表的插入更新刪除等操作，會佔用大量的活動日誌，如果用戶不希望對這些
操作不做日誌記錄可以使用activate not logged initially，
對於不記錄事務日誌的問題是：
1.db2的rollback和rollforward都依賴日誌，如果沒有記錄日誌，該事務如果rollback了(鎖超時，
內存不足等)，那麼會導致該表不可以訪問；
2.歸檔日誌模式下的數據庫的restore+rollforward，如果rollforward到不記錄日誌操作的
時間點後，也會導致該表不可訪問，只能drop了重建,所以應當在這些不記日誌操作之後
立刻對數據庫或表空間做一個備份。
DB2 load導入數據的操作也是不會通過事務日誌來記錄變化，所以load操作提供copy yes
和copy no的參數，no是load結束後要手動備份，yes是load的過程同時對數據做了一個備份。
db2 "load from tb1.del of del insert into tb2 copy yes to /db2cfg"
db2 load query table tb2
1.事務中開啓不記錄日誌,事務rollback後，表不可訪問:
[test@demo db2cfg]$ db2 +c "alter table tb1 activate not logged initially" ---->只在該事務中tb1不記錄日誌
DB20000I The SQL command completed successfully.
[test@demo db2cfg]$ db2 +c "insert into tb1 values(666,'yo666') "
DB20000I The SQL command completed successfully.
[test@demo db2cfg]$ db2 rollback
DB20000I The SQL command completed successfully.
[test@demo db2cfg]$ db2 "select * from tb1"
ID NAME
----------- ----------
SQL1477N For table "TEST.TB1" an object "4" in table space "4" cannot be
accessed. SQLSTATE=55019
2.前滾到不記錄時間之後，表不可訪問，若在不記錄日誌操作後立即備份，便可解決問題
1>首先做一次全備
[test@demo db2cfg]$ db2 backup db testdb online
Backup successful. The timestamp for this backup image is : 20190108183351
2>執行一個事務不記錄日誌，後立刻對該表空間做了備份
[test@demo db2cfg]$ db2 +c "alter table tb1 activate not logged initially"
DB20000I The SQL command completed successfully.
[test@demo db2cfg]$ db2 +c "insert into tb1 values(666,'yo666') "
DB20000I The SQL command completed successfully.
[test@demo db2cfg]$ db2 commit
DB20000I The SQL command completed successfully.
[test@demo db2cfg]$ db2 "backup db testdb tablespace(ts2) online"
Backup successful. The timestamp for this backup image is : 20190108183712
3>往ts2表空間的tb1表和tb2表都再插入一些數據
[test@demo db2cfg]$ db2 "select * from tb1"
ID NAME
----------- ----------
1 yo1
2 yo2
3 yo3
666 yo666
4 record(s) selected.
[test@demo db2cfg]$ db2 "select * from tb2"
ID NAME
----------- ----------
1 yo1
2 yo2
3 yo3
3 record(s) selected.
db2 "insert into tb1 values(6,'yo6'),(66,'yo66')"
db2 "insert into tb2values(6,'yo6'),(66,'yo66')"
4>恢復數據庫並前滾至最新日誌狀態
db2 restore db testdb taken at 20190108183351
db2 rollforward db testdb to end of logs and complete
[test@demo db2cfg]$ db2 "select * from tb2" --->tb2表顯示是最新狀態
ID NAME
----------- ----------
1 yo1
2 yo2
3 yo3
6 yo6
66 yo66
5 record(s) selected.
[test@demo db2cfg]$ db2 "select * from tb1" --->tb1表則不可用
ID NAME
----------- ----------
SQL1477N For table "TEST.TB1" an object "4" in table space "4" cannot be
accessed. SQLSTATE=55019
5>使用不記錄日誌後的表空間備份再一次恢復
[test@demo db2cfg]$ db2 "restore db testdb tablespace(ts2) taken at 20190108183712"
DB20000I The RESTORE DATABASE command completed successfully.
[test@demo db2cfg]$ db2 "rollforward db testdb to end of logs and complete tablespace(ts2)"
Rollforward Status
Input database alias = testdb
Number of nodes have returned status = 1
Node number = 0
Rollforward status = not pending
Next log file to be read =
Log files processed = -
Last committed transaction = 2019-01-08-10.45.13.000000 UTC
DB20000I The ROLLFORWARD command completed successfully.
[test@demo db2cfg]$ db2 "select * from tb1" ---->tb1和tb2都正常並前滾到最新狀態
ID NAME
----------- ----------
1 yo1
2 yo2
3 yo3
666 yo666
6 yo6
66 yo66
6 record(s) selected.