DAY 06 – TABLESPACE


Ü  STORAGE MANAGEMENT

q  HOW IS THE DATA STORED IN THE DATABASE?

v  LOGICALLY STORE IN THE TABLESPACE AND PHYSICALLY WE HAVE DATA FILES

q  TABLESPACE

v  COLLECTION OF SEGMENTS

q  SEGMENT

v  COLLECTION OF EXTENTS

q  EXTENT

v  COLLECTION OF BLOCKS

q  BLOCK

v  DATA BLOCK IS THE SMALLEST UNIT

q  INITIALLY 8 BLOCKS ARE ALLOCATED BY DEFAULT TOTAL SIZE [8KBx8] 64KB

q  ONE TABLE WILL HAVE A NUMBER OF EXTENTS

q  ONE BLOCK HAS 5 PARTS

q  COMMON AND VARIABLE HEADER

v  BLOCK ADDRESS [EX: DATA OR INDEX]

q  TABLE DIRECTORY

v  IN THIS BLOCK WHICH TABLE DATA STORE

q  ROW DIRECTORY

v  WHICH ROW STORE IN THIS BLOCK

q  FREE SPACE

v  ALLOCATED FOR INSERTION OF NEW ROWS

q  ROW DATA

 

Ü  TABLESPACE

q  SMALL FILE TABLESPACE

v  IN A TABLESPACE 1024 DATA FILES YOU CAN ADD

v  ORACLE RECOMMENDS ONE DATA FILES SIZE MAX 32 GB

q  BIGFILE TABLESPACE

v  LIMIT SIZE 32TB [OS & ORACLE LEVEL]

v  ONLY ADD ONE DATA FILE

v  SHOULD ONLY BE USED WITH ASM OR WITH OTHER LOGICAL VOLUME MANAGERS 

q  SYSTEM TABLESPACE

v  CONTAINS DATA DICTIONARY TABLES [META DATA]

q  SYSAUX TABLESPACE

v  CONTAINS EMBEDDED ENTERPRISE MANAGER[EM] REPOSITORY, LOGMINER, STATSPACK, AWR

q  UNDO TABLESPACE

v  ROLL BACK TRANSACTIONS        

q  USER TABLESPACE

v  ACTUAL USER DATA

q  TEPORARY TABLESPACE

v  FOR SORT OPERATIONS PURPOSES


q  TABLESPACE TWO TYPES

q  LOCALLY MANAGED TABLESPACE

v  USED FOR DML OPERATIONAL [INSERT, UPDATE, DELETE WITH DATA GETTING MODIFIED]

q  DICTIONARY MANAGED TABLESPACE

v  STATIC TABLE [MASTER TABLE]

v  WE DO NOT MODIFY DATA

v  SYSTEM AND SYSAUX ARE IN INCLUDE THIS TABLESPACE

 

q  EXTENT MANAGEMENT HAS TWO TYPES

q  AUTOALLOCATE

v  EXTENT SIZES ARE MANAGED BY ORACLE AUTOMATIC

q  UNIFORM

v  EXTENT ALLOCATION IN THE TABLESPACE IS IN A FIXED UNIFORM SIZE

 

Previous Post Next Post

نموذج الاتصال