What we should consider in Oracle Database?

Read this Oracle Tutorial Point article to know what is oracle database and what should we consider in oracle database. As per Oracle database management system, database is a collection of data in one or additional files. The database will contain physical and logical structure. The course of developing associate application consists of,
  1. Creating Structures (Table & Indexes).
  2. Creating Synonyms for the Object names.
  3. View objects in different databases.
  4. Restricting access to the objects.
External tables will be accessed for files outside the database, as if the rows within the files were rows within the table. associate Oracle instance includes of
  1. A memory area/space called System Global Area (SGA)
  2. Background process which interacts between the SGA and the database files on disk.
  3. The Oracle Read Application Cluster (RAC) can create more than one instance to use a similar database.
Database as per Oracle:
Within the oracle database, the basic structure may be a table. The various tables supported by oracle database are,
  1. Relational Table's
  2. Object Relational Table's
  3. External Table's
  4. Index Organized Table's
  5. Temporary Table's
  6. Partitioned Table's
  7. Clustered Table's
  8. Dropped Table's
  9. Materialized View's
The access to the data in the tables in tuned by indexes, they are
  1. B+ Tree Indexe's
  2. Bitmap Indexe's
  3. Reverse Key Indexe's
  4. Function Based Indexe's
  5. Text Indexe's
  6. Partitioned Indexe's
Data Storage style in Oracle:
All the logical structures in the database should be stored in the database. Oracle maintains a data dictionary, which records METADATA about objects. The objects which require physical area that are allocated space within a TableSpace.

TableSpaces:
It consists of one or more data files. A data file can be a part of one and only one table space. As per Oracle minimum table space is made are,
  • SYSTEM and SYSAUX : Which are used to support its internal management needs.
In Oracle a big file tablespace can be created, which can grow to the size of Terabytes. The oracle managed files conception is accustomed to simplify the creation and maintenance of data files.

Temporary TableSpaces:
The actual table space is permanent. However the segments saved within the table area are temporary. It is used to support sorting operations. That are index creation and joint processing. Table can be either Dictionary Managed / Logically Managed. Oracle maintenance a picture in every file of the table area to trace space availability.

Automated Storage Management (ASM):
It automates the layout of data files and other operating system level files, used by the database. It is done by distributing the files across all on the market disks. It supports multiplexing features, minimizing the possibility of data loss. As new disks are supplemental, the information files are mechanically decentralized access to all disks in the defined group for optimal performance.

Automatic UNDO Management:
The transactions are supported to dynamically create and manage undo segments. It helps in maintaining prior pictures of the modified blocks and rows. The UNDO segment is managed directly without the intervention of the DBA's. Flashback version queries are often executed to see different versions of a row as it changed during a given time interval.

Dropped Data:
The Recycle Bin concept was introduced in Oracle Database. This recycle bin concept impacts the space requirements for the tablespaces and datafiles. The recycle bin architecture greatly simplifies recoveries of accidentally dropped table's. This idea might significantly increase space used in the database. The PURGE command is used to get rid of previous entries from the recycle bin.

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