Oracle getting started Tutorial: Solve the sequence disconnection problem in the ADF

When the Sequence is defined, if the cache is used, a Sequence jump occurs when the database is closed or down.

To solve the sequence disconnection number in the ADF program, make sure that the Oracle database does not generate a disconnection number.

1. For infrequently used Sequence, you can add NOCACHE in the definition, that is, no cache. In this way, the database will not be disconnected.

2. For frequently-used Sequence, CACHE is used for definition. You can use DBMS_SHARED_POOL to cache keep sequence.

The command is as follows:

1. ExecDbms_shared_pool.keep (Name=>'Myseq', Flag =>'Q')

Test:

1) DBMS_SHARED_POOL is not set

1. SQL>Create SequenceMyseq cache 100;
3. The sequence has been created.
5. SQL>SelectMyseq. nextvalFromDual;
7. NEXTVAL
8. ----------
9. 1
11. SQL> conn/AsSysdba
12. Connected.
14. SQL>AlterSystem flush shared_pool;
16. The system has been changed.
18. SQL> conn hr/hr
19. Connected.
21. SQL>SelectMyseq. nextvalFromDual;
23. NEXTVAL
24. ----------
25. 101

2) Set DBMS_SHARED_POOL

1. SQL> conn/AsSysdba
2. Connected.
4. SQL>ExecDbms_shared_pool.keep (Name=>'Hr. myseq', Flag =>'Q');
6. The PL/SQL process is successfully completed.
8. SQL>AlterSystem flush shared_pool;
10. The system has been changed.
12. SQL> conn hr/hr
13. Connected.
14. SQL>SelectMyseq. nextvalFromDual;
16. NEXTVAL
17. ----------
18. 102

3. To avoid the Sequence break generated by clicking the new button in the ADF application, you can use the technique of defining the field type as DBSequence and combining Trigger.

For the method of using DBSequence In the ADF, refer to my other article: summary of the method of using Sequence in the ADF.