Oracle Learning Notes (iii)

ORACLE Learning notes

ORACLE Staging tables and versions

storage structure for ORACLE tables:

control the structure of the file:

Data files:

the structure of the BLOCK:

Table Delete Comparison:

The storage structure of the row:

The line is tightly stored in the block, and the wardrobe holds the information for the lock.

Data files:

Compress stored data:

structure of the index ( tree-like structure )

relationship of foreign keys and indexes

Oracle database version vs. built-in Administrator

Orcale Network Structure

Database files

Oracle Database Process

Oracle data File Structure

A segment consists of one or more coiled, a coiled is a number of contiguous allocated blocks.

The block size of the database is fixed when the database is created, and the capacity of each block in the database is the same.

segment (segment): database objects, such as tables, indexes, and so on, each of which creates a segment when it is created.

Disk Area (extent): A contiguous allocation of space in a file. Each segment starts at least one disk area, and two disk intervals are not necessarily adjacent to each other. The capacity range of the panel ranges from one block to 2GB.

block : the block is the smallest unit of space allocation in Oracle . Blocks are places where data rows, index items, and temporary sorting results are stored. The block size is usually 2KB, 4KB, 8KB, 16KB, 32KB.

Structure of The Block

Size : contains information such as the type of block (table block, index block) , and the address of blocks on the disk for active and obsolete transactions on the block

Table directory: Information about the tables in a block that store each row

Row directory: Information about the description line found in the block. This is a pointer array that contains the data portion of the block row.

Table Space: a container for saving segments, each of which belongs to a table space. A table space has more than one segment, and a segment never crosses a table space boundary. The tablespace itself has one or more data files associated with it. The extents of any given segment in the tablespace are fully contained in a single data file. A segment can have extents from different data files.

Temporary files

temporary files are a special type of data file, when memory is insufficient in when a large-scale sort operation is saved in RAM,Oracle uses temporary files to store them.

Oracle Learning Notes (iii)