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Dr. Ouyang, CS 643, Spring 2001. Reasons for Replication. Availability
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1. Dr. Ouyang, CS 643, Spring 2001 http://technet.oracle.com/doc/oracle8i_816/server.816/a76959/toc.htmhttp://technet.oracle.com/doc/oracle8i_816/server.816/a76959/toc.htm
2. Dr. Ouyang, CS 643, Spring 2001
3. Dr. Ouyang, CS 643, Spring 2001 Allows multiple sites, acting as equal peers, to manage groups of replicated database objects. Applications can update any replicated table at any site. Using asynchronous replication means that conflicts are possible because the same row value might be updated at two different master sites at nearly the same time. Allows multiple sites, acting as equal peers, to manage groups of replicated database objects. Applications can update any replicated table at any site. Using asynchronous replication means that conflicts are possible because the same row value might be updated at two different master sites at nearly the same time.
4. Dr. Ouyang, CS 643, Spring 2001 Applications can query data from read-only snapshots to avoid network access regardless of network availability. However, applications throughout the system must access data at the master site to perform an update. Applications can query data from read-only snapshots to avoid network access regardless of network availability. However, applications throughout the system must access data at the master site to perform an update.
5. Dr. Ouyang, CS 643, Spring 2001 Allows users to insert, update, and delete rows of the target master table by performing these operations on the snapshot.Allows users to insert, update, and delete rows of the target master table by performing these operations on the snapshot.
6. Dr. Ouyang, CS 643, Spring 2001
7. Dr. Ouyang, CS 643, Spring 2001
8. Dr. Ouyang, CS 643, Spring 2001
9. Dr. Ouyang, CS 643, Spring 2001
10. Dr. Ouyang, CS 643, Spring 2001 http://technet.oracle.com/doc/oracle8i_816/server.816/a76958/creater3.htm#11709http://technet.oracle.com/doc/oracle8i_816/server.816/a76958/creater3.htm#11709
11. Dr. Ouyang, CS 643, Spring 2001 http://technet.oracle.com/doc/oracle8i_816/server.816/a76958/creater4.htm#18519http://technet.oracle.com/doc/oracle8i_816/server.816/a76958/creater4.htm#18519
12. Dr. Ouyang, CS 643, Spring 2001 For more information about PL/SQL, see
http://technet.oracle.com/doc/oracle8i_816/appdev.816/a77069/toc.htmFor more information about PL/SQL, see
http://technet.oracle.com/doc/oracle8i_816/appdev.816/a77069/toc.htm
13. Dr. Ouyang, CS 643, Spring 2001
14. Dr. Ouyang, CS 643, Spring 2001
15. Dr. Ouyang, CS 643, Spring 2001
16. Dr. Ouyang, CS 643, Spring 2001
17. Dr. Ouyang, CS 643, Spring 2001
18. Dr. Ouyang, CS 643, Spring 2001
19. Dr. Ouyang, CS 643, Spring 2001 This figure shows a database application with some SQL statements that implicitly fire several triggers stored in the database. Notice that the database stores triggers separately from their associated tables. This figure shows a database application with some SQL statements that implicitly fire several triggers stored in the database. Notice that the database stores triggers separately from their associated tables.
20. Dr. Ouyang, CS 643, Spring 2001 When a trigger fires, a SQL statement within its trigger action potentially can fire other triggers, resulting in cascading triggers.
When a trigger fires, a SQL statement within its trigger action potentially can fire other triggers, resulting in cascading triggers.
21. Dr. Ouyang, CS 643, Spring 2001
22. Dr. Ouyang, CS 643, Spring 2001
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26. Dr. Ouyang, CS 643, Spring 2001