ORACLE 11G from scratch-20141208, 11g-20141208
Section 1.3.6
It is used to store all the data of an object with an independent storage structure defined in a tablespace. It consists of one or more zones.
1. Data Segment
Used to store all data in a table.
2. Index segment
Used to store all the data of an index.
3. Temporary Section
Used to store temporary data generated by sorting operations.
4. rollback segments
It is used to store the values before the user data is modified, so that the user can roll back the data modification under specific conditions.
1.3.7. Zone
A block that is physically stored continuously. It is the smallest unit of storage allocation. It consists of one or more blocks, and one or more zones form segments.
1.3.8. Data blocks
The smallest Data Management Unit is also the smallest unit for performing input and output operations. The minimum unit for the operating system to perform input/output operations is the operating system block.
Components:
1. Block header: attribute information, such as the block's physical address and the block type.
2. Table Directory: if the data stored in the block is table data, the table directory stores information about the table.
3. Row directory
4. Free Space:
5. Row Space: the storage space used in the block. Table or index data is stored in the row space.
1.4 New Features of oracle 11g
1.4.1 Database Management
1. Plan Management
Allows you to fix the query plan of a specific statement. No statistical data or database version changes will change your query plan.
2. Resource Manager
Manage CPU and I/O. Set the priority of a specific file, file type, and ASM Disk
3. Access the recommender
4. Repeat the database
Capture the load of the entire database and pass it to a test database created from the backup or standby database. Then, you can repeat the test results after the system optimization.
5. Event packaging service
6. Automatic SQL Optimization
7. database backup and recovery
8. Automatic Diagnosis Knowledge Base
9. Automatic Memory Optimization
PGA, SGA