Oracle Database Design Masters Score 10

If you have this table structure, it will be really difficult to check, but you can complete the operation at the business layer--- you can first query all the personnel who were transferred in a certain shift in May--- and divide them into two checks: 1Query out of the call-up, 2Query the incoming and out,And then you query the person who appears on the flight,You do a loop at the business layer,Match the same ID and delete the object.。。。

This method will be less efficient than if you were to get it directly from the database, but your table structure is really hard to look up, so if you are in a hurry to complete the task, you may want to do it the way I said first.

There is nothing wrong with the design, it is normal, it is nothing more than designing an algorithm, and it does not need to be accumulated, there is no difficulty.

What should be displayed to specifically query the personnel of a class in May this year? Do you only show the number of class members in May or are you in and out?

The design of the 1st floor is to add a history class situation, in fact, the record has been satisfied, nothing more than a forward push, a reverse push.

And the assumption on the 1st floor is that there is an initial table, why do you have to have an initial table? Normally, there should be a current table, right?

It's not a bug, it's actually right to design it that way. When designing the database, try to consider data redundancy. If you want to display different forms of data at the business level, you can do it according to the relationship between these tables. There is no need to create as many tables as the business layer needs.

Choose the appropriate installation version according to the hardware situation of your computer, and the installation method is not special with other software installations, among which you should pay attention to the password of sys.

1) Demand analysis stage: demand collection and analysis, to the data dictionary and data flow diagram.

2) Conceptual structure design stage: synthesize, summarize and abstract user needs, form a conceptual model, and represent it with an e-r diagram. (3) Logical structure design stage:

Transform a conceptual structure into a data model supported by a DBMS. (4) Database physical design stage: select a physical structure that is most suitable for the application environment for the logical data model.

5) Database implementation stage: establish the database, compile and debug the application, organize the data storage, and run the program for trial operation. (6) Database operation and maintenance stage:

Evaluate, adjust and modify the database Lingye Mountain system.

The Oracle database optimization scheme is mainly designed from several different aspects:

One. Optimal flexible architecture (OFA) for database optimization

2. Make full use of the System Global Area (SGA).

3. Optimization strategies in database design.

Data should be organized into two categories: frequently accessed data and frequently modified data. For frequently accessed but infrequently modified data, the internal design should be physically non-normalized.

For data that is frequently modified but not frequently accessed, the internal design should be physically standardized.

Fourth, reasonable design and management of the table.

1. Use table partitioning.

Partitions physically separate data, and data from different partitions can be stored in data files on different disks.

2. Avoid row joining and row migration.

3. Control fragmentation.

4. Use of aliases.

Aliases are the application skills of large databases, that is, the table names and column names are aliased by one letter in the query, and the query speed is twice as fast as that of creating a join table.

5. Alternate use of rollback sections.

5. Optimal design of index.

1. Manage organizational indexes.

Indexes can greatly speed up database queries, and indexes can map logical values in tables to secure rowids, so indexes can quickly locate physical addresses in data sheds.

6. The use of multi-CPU and parallel query PQO (Parallel Query Option).

7. Implement the system resource management and allocation plan.

Oracle provides Database Resource Manager (DRM) to control the allocation of resources for users, which can be used by DBAs to allocate the percentage of system resources for user classes and job classes. In an OLDP system, 75% of the CPU resources can be allocated to online users, and the remaining 25% can be reserved for batch users. In addition, it is possible to allocate CPU at multiple levels.

In addition to CPU resource allocation, DRM can also restrict the ability to perform parallel operations on resource user groups.

8. Use the optimal database connection and SQL optimization scheme.

9. Make full use of the background processing scheme of data to reduce network traffic.

1. Reasonably create a temporary table or view chain.

2. Make full use of database packaging technology.

Use the database description language to write a process or function of the database, and then package the procedure or function into a package and run the package in the background of the database.

3. Data replication, snapshots, views, and the use of remote procedure call technology.