1.
INTRODUCTION
TO
ORACLE ARCHITECTURE
PRESENTED BY
http://www.orienit.com

2.
Client
Computer
Applic
ation
Server
Oracle
Database
Lan Or
Internet
Lan Or
Internet
Client Server Environment
Application By Java or .Net
Framework www.orienit.com

3.
Oracle Versions
• E.F.T. Codd implement rules for RDBMS.
• Oracle 7 ( Implements 7 Rules)
• Oracle 8 (First stable version of Oracle)
• 9i (integrated with java and supports all
utilities which are used By Java.)
• 10G (Data Grid)
• 11i called Oracle Financials Strong
competitor for SAP and ERP.
• JD Adward, People Soft, SBAAN are new
competitor to SAP and ERP.
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4.
Oracle Platforms
• Solaries is the 1st
oracle platform provided by Sun
Micro system ( Now JAVA is oracle prod).
• Oracle for Linux.
• PWR Builder introduce by oracle used for data ware
housing competitor for ETL sys. By Informetica.
• Cognos powerful tool as Infor. Used for data ware
housing.
• ERWIN strong competitor to Oracle designer.
• IDE as VB & .NET called SQL developer & J Dev.
• Mysql, Teradata, sybase, DB1,DB2, MS. Sql server.
• 3rd
Party tools as TODD by Quest Technology.
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5.
What is Data?
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6.
Data is Defined as
• A value for an attribute of an entity.
• Entity is Real World Thing which exist
and can be described in terms of one or
more attributes.
• Database is Organized value of all
SAME type of entity.
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7.
Memory of ORACLE( Data
Dict.)
 Arrangement of system
table stores data about data
called as METADATA.
 RDBMS discovered for non
procedural access.
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8.
Storage
LOGICAL PHYSICAL
Table
Space
Schema
Parameter File,
Control File,
Redo Log File,
Data File
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9.
Parameter File
 This is the first file oracle read at start of
the database. Parameters are system
variables sets environment of system,
file also called as init.ora.
 From Oracle 9i SPFILE is introduce and
this file is binary formatted and it is the
binary version of init.ora.
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10.
Control File
 Its important file of Oracle Database and
if control file is lost it means no recovery
is possible also it is binary formatted.
 Oracle multiplex the file and stored in 3
files same locations name as
control1.ctl, control2.ctl, control3.ctl.
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11.
3 Important Numbers
• SCN : System Change Number.
It is assigned by oracle to every committed
transaction always increasing..
• LSN: Log Sequence Number.
The sequential number assign to redo log as
they get filled and recycled.
• CPC : Check Point Counter.
Its is also ever increasing number and to
every check point is assigned.
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12.
Logical Database
Structure Oracle uses logical database structure to store data
on physical operating system file.
 DATA BLOCK : Is the foundation of oracle storage. It consist
of number of bytes of disk space in OS.
 EXTENT : An extents is two or more contagious oracle data
blocks and a unit of space allocation.
 SAGMENT : A segment is a set of extents allocated to logical
structure like table or oracle objects.
 TABLESPACE : A table space is a set of one or more
data files consist of related Segments.
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13.
Schema
• Schema is set of objects own by User Account.
• Each schema has user account but each user
don’t need schema.
• A user account is account with database having
privileges to perform predefined activities on
data.
• Schema may not exist with user account but
user account is exist without schema.
• Purpose : Maintenance of object like backup &
recovery, implementation of security and access
level.
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14.
Redo Log File
 Oracle used redo base recovery and allow to
recover only committed transaction till the point of
failure.
 The redo base recovery in oracle is implemented
through the redo log file.
 When system fails then oracle read history from
these redo log file and guaranties the recovery till
the point of failure.
 These files are created at the creation of oracle db.
 The files are reusable and used as round robin
passion.
 Maximum size is 50Mb.
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15.
Redo Log Copies stored to 10 different geographic locations
Redo log
1
Redo log
2
Log Switch
Redo
log 7
Redo
log 6
Redo
log 5
Redo
log 4
Redo
log 3
Redo
log 2
Redo
log 1
Redo
log N..
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16.
System Global Area SGA
S
Shared
SQL
Area
Share
d pool
area /
Data
Diction
.
Redo Log Buffer
Large
Pool
Fixed
TtPool
Data
Buffer
Pool
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17.
3 Types of Buffer
 Free Buffer : A buffer which is ready to take
new data.
 Pinned Buffer : A buffer which have data
under use (not committed or not rollback.)
 Dirty Buffer : A buffer which have data which
is committed called permanent.
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18.
LRU Algorithm
• List Recently Used : This algorithm is used to write data
from data buffer pool (dirty buffers) in to data files.
Data Buffer Pool: Divided into 3 sections.
Keep Buffer Pool : It holds the frequently requested data.
(Based on MRU).
Recycle Buffer Pool : The data which is not requested
immediately after used is loaded in recycle buffer pool
and eliminated after used.
Default Buffer Pool :The data which is not required in
above pools is loaded in this pool.
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19.
Redo Log Buffer
• The redo log buffer is the place where
data or entries are stored before writing
to redo log file.
• All entries are written in serially to redo
log file due to SCN.
• When user commits the data the data
written to redo log file.
• If not commit or rollback then 75% full
written to redo log file.
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20.
Shared Pool Area
• This is the most busy area of SGA.
• 3 stages of SQL.
• Parsing : It resolve the reference made to the
different object in SQL statement resolution of
privileges.
• Planning : After parsing the statement hand
over to Optimizer for drawing execution plan to
performing activities in SQL statement.
Optimizer breaking down the SQL statement
to get result.
• Execution : To get result and display as per
request.
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21.
Parsing Types
 Hard Parse
 Soft Parse
 Important Processes
 Reco
 Lck
 Smon
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22.
Thank you
Presented by OrienIT