Oracle apps dba training dba technologies
- 1. WELCOME TO DBA TECHNOLOGIES ORACLE DATABASE ARCHITECTURE – 1 By Mr. PRASAD MYNUMPATI 18 Years Real Time in INDIA-USA http://www.dbatechnologies.net/ www.dbatechnologies.net Building Career With Passion
- 2. Architecture Main components of Architecture 1. ORACLE INSTANCE SGA (Memory) & Background Process 2. ORACLE DATABASE Storage Level
- 3. ORACLE Instance Architecture – SGA What is ORACLE INSTANCE? Physical Memory (SGA) & Processes SGA should be able to open in physical memory What is SWAP? Swap also a type of file system on HDD, it is used by OS when Real memory usage is at high Swap must be available before installing Oracle Software
- 4. Oracle Instance Architecture – PROCESSES Each connection to UNIX operating system is process While starting up instance – SGA (Memory Structures) – Background Process ($ps) Background process are required to manage memory structures and database files. Some of the important background process are: DBWn, LGWR, SMON, PMON, ARCH,RECO
- 5. Instance Architecture SGA - Mandate and Optional memory structures and background processes Streams Pool Large DBWn LGWR SMON PMON CKPT RECO
- 6. What is ORACLE DATABASE? ORACLE DATABASE is a combination of 3 different types of files Different types of files (C,R,D) -Control Files -Redo log files -Data files
- 7. DB Architecture - Control Files Control Files – Holds data about database structure (physical database structural information) Importance of control file – Database can not be started with out control file – Multiplexing to support from failures – Supports up to 8 file copies
- 8. DB Architecture – Control Files Contents of Control file • Database Name and database id • Database creation date and time • All database file names (data files) • Location of each data file • Age of each file (Checkpoint Information) • Current online log sequence number • Checkpoint number • Backup information
- 9. DB Architecture - Data File Data Files Stores actual data permanently in ORACLE proprietary files called data files. Data files are going to be on file system like -UNIX -EXT2 -EXT3 -NTFS (in case of windows) Minimum 3 data base files are required from 10g -System -Undo -Sysaux
- 10. DB Architecture - Redo log files Stores all changes in the form of change vectors for recovery Changes are saved to Data Files and Redo Log Files – what is the difference? Changes to REDO LOG FILES are in the form of change vectors – Block id – File id – Change details Changes to Data files are in the form of rows and blocks
- 11. DB Architecture Control files : minimum 1. Stores Database structural information. Recommended 3 files. Disk1 Control Disk2 Control Disk3 Control Data files : Minimum 3 from 10g. Stores data permanently for retrieval purpose. System Undo Sysaux Redo log files: Minimum -2 holds all changes in the form of changes vectors for recovery Rego1a .log Redo2a .log
- 12. Oracle Server Oracle Server is the combination of Oracle Instance & Oracle database. Database access is only via Instance SGA Database > Select From Emp; User Process DBBC SP LC DDC REDO LOG BUFFERS Back ground Processes Control Redo Data Files
- 13. Logical and Physical aspect of Oracle database DATABASE PHYSICAL LOGICAL Control Files Data Files Redo Log Files Tables Views Procedures Triggers
- 14. IS INSTANCE PHYSICAL OR LOGICAL ? LOGICAL INSTANCE PHYSICAL ? NEITHER IT IS VOLATILE
- 15. ORACLE Database TS Architecture SYSTEM TABLE SPACE SYSAUX TABLESPACE UNDO TABLESPACE TEMPORARY TABLESAPCE DATA TABLESPACE INDEX TABLESPACE
- 16. Database Architecture – SYSTEM TS Users should not keep application data on SYSTEM tablespace.It is only to support base tables like. TAB$ COL$ IND$ Base Tables are created during the creation of data base to support metadata.
- 17. Database Architecture – SYSAUX TS SYSAUX tablespace introduced in version 10g Supports work load repository Reports such as AWR and ADDM willmake use of SYSAUX to generate reports Helps in understanding the performance at SERVER level
- 18. Database Architecture – UNDO TS UNDO tablespace is to support image during DML operations Supports Read consistency Flashback operations Rollback transactions Contents of UNDO TS type is UNDO it is not permanent
- 19. Building career with passion QUESTION AND ANSWER SESSION DSNR:944 11 72 718/040-65555689 www.dbatechnologies.net