ORACLE 8 OBJECT ORIENTED TECHNOLOGY ORACLE SOFTWARE STRUCTURES SERVER SIDE BACKGROUND PROCESSES DATABASE SERVER AND DATABASE INSTANCE

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1 ORACLE 8 IS ORDBMS HANDLES VLDB - GIGABYTES/TERABYTES 10,000 CONCURRENT USERS PARTITIONED TABLES AND INDEXES SINGLE DATA BLOCK IS INACCESSSIBLE CAN ACCESS MULTIPLE PARTITION IN PARALLEL FOR CONCURRENT USERS MANAGEMENT NET 8 (SQL * NET ) ENHANCES OPEN NETWORK CONNECTION TO SERVER TO AVOID O.S. RESTRICTIONS FOR NO. OF SESSIONS THROUGH MULTIPLEXING, CONNECTION POOLING AND CONCENTRATION OF APPLICATION REQUESTS AUTOMATED PROTECTED PARALLEL PROCESSING ENHANCEMENTS PARALLEL QUERY ENHANCEMENTS INTRA-PARTITION PARALLELISM INTER-PARTITION PARTION-AWARE PARALLEL SERVER ENHANCEMENTS NCA ARCHITECTURE MULTI THREADED ARCHITECTURE CLIENT SERVER ARCHITECTURE DATA BASE MANAGEMENT & SECURITY SERVER-MANAGED BACKUP & RECOVERY INCREMENTAL BACKUPS POINT IN TIME RECOVERY OF INDIVIDUAL TABLESPACES PASSWORD MANAGEMENT DISTRIBUTED DATABASES REPLICATION ENHANCEMENTS DISTRIBUTED SECURITY DOMAINS HETEROGENOUS DATA ACCESS OBJECT ORIENTED TECHNOLOGY OBJECT ORIENTED DATABASES CREATE OR REPLACE TYPE SALES.PART_TYPE AS OBJECT ( ID INTEGER DESCRIPTION VARCHAR(50) ON_HAND INTEGER RECORD POINT INTEGER MEMBER FUNCTION PART_ID ( DESCR IN VARCHAR ) RETURN INTEGER ) ; OBJECT TYPES, CLASSES AND OBJECTS ATTRIBUTES AND METHODS ORDER_PART PART_TYPE Attributes PARTS ID _ON_ DESCRIPTION HAND ON_HAND REORDER_POINT Methods ORACLE SOFTWARE STRUCTURES DATABASE SERVER AND DATABASE INSTANCE COMMONLY REFERRED AS DATA BASE INSTANCE IS COLLECTION OF SERVER SIDE PROCESS AND MEMORY AREAS THAT ORACLE USES Oracle database instance Background server processes Memory areas Shared global area buffer cache Shared pool OBJECT VIEWS An object type (a class) has attributes to describe the corresponding object, as well as methods that allow applications to work with objects of the class. SERVER STARTUP AND SHUT DOWN 1) START AN INSTANCE 2) MOUNTING 3) OPEN THE DATABASE AFTER SERVER START UP NOW THE DATABASE IS AVAILABLE FOR USERS SHUTDOWN DISMOUNT SHUT DOWN THE INSTANCE SERVER CRASHES ABNORMAL SERVER SHUT DOWN KILLING OF ONE OR MORE BACKGROUND PROCESS BY O.S. OPERATION ORACLE 8 HAS AUTOMATIC RECOVERY FEATURES SERVER SIDE BACKGROUND PROCESSES Data files Transaction log DBWR PARALLEL SERVER OPTION AND HIGH AVAILABILITY MULTIPLE DATABASE INSTANCES RUNNING ON DIFFERENT NODES, MOUNT AND OPEN THE SAME ORACLE DATABASE IN PARALLEL CKPT PMON LGWR SERVER CONNECTION USERS CAN WORK WITH THE DATABASE THROUGH ANY INSTANCE THAT IS MOUNTED TO THE DATABASE AFTER AN ORACLE INSTANCE IS UP AND RUNNING YOU CAN ESTABLISH A CONNECTION WITH THE SERVER TO PERFORM DATABASE WORK SMON Other server processes ARCH Archeived transaction log DISTINCT VERSUS MULTITHREADED BACKGROUND PROCESSES

2 CLIENT SERVER PROCESS ARCHITECTURE DEDICATED SERVER ARCHITECTURE Dedicated s Instance NETWORK MULTITHREADED SERVER Instance SINGLE-TASK SERVER PROCESS ARCHITECTURE DUMB TERMINAL Single Task Instance Dispatcher Shared Access Code Client Code Request and response queues A host-based system uses a single-task server process architecture MEMORY AREAS AND DATA CACHING CACHE HITS ( GETS ) CACHE MISS CACHE RELOAD ( DATA AGED ) CACHING ALGORITHMS - MOST RECENTLY USED MRU/LRU BUFFER CACHE Instance Foreground Memory Cache Cache miss or reload causes disk access Buffer Cache Cache hit does not create disk access File on disk DBWR Blocks age from cache back to disk To cache data intelligently, an application uses a caching algorithm that maximizes cache hits and minimizes cache mises and cache reloads. Foreground server processes read data into an Oracle instance s buffer cache to perform database work. Eventually, the DBWR background process writes dirty data blocks form the buffer cache back to the database s data files. YOU CAN INCREASE THE BUFFER CACHE SIZE THE SHARED POOL

3 THE SHARED POOL ORACLE NET8 AS SQL*NET LIBRARY CACHE AND SHARED SQL THE DICTIONARY CACHE SHARED POOL SIZE SGA PGA SORT AREAS TEMPORARY WORK SPACE Instance Shared Pool Foreground CONNECTION POOLING MULTIPLEXING TNS LISTENER WEB LISTENER Client Net 8 on the Client Protocol Adapter Network Net 8 on the Library Cache UPDATE... Dictionary Cache UPDATE... TNS Layer UPDATE... NET Layer An instance s shared pool contains two memory areas: the library cache and the dictionary cache. Net 8 makes the network between the clients and servers of an application transparent CONNECTION POOLING MULTIPLEXING TNS Connection TNS Connection Idle Host OS Idle Network Transport Idle Connection pooling allows database sessions to use a set number of physical TNS connections and reduce network overhead. Multiplexing many network connections into a single physical network transport to reduce the operating system overhead. TNS LISTENER WEB LISTENER TNS ADDRESSING TNS NAMES.ORA - THE TNS NAMES.ORA CONFIGURATION FILE RESIDES ON BOTH CLIENTS AND SERVERS IN AN ORACLE NETWORK. SQLINET.ORA - THE SQLNET.ORA CONFIGURATION FILE RESIDES ON BOTH CLIENTS AND SERVERS IN AN ORACLE NETWORK. SQLNET.OPRA CONTAINS SPECIAL CONFIGURATION PARAMETERS THAT CONFIGURE A SQL *NET CONNECTION FROM A CLIENT OR SERVER TO ANOTHER ORACLE SERVICE IN A NETWORK. MULTIPLE NETWORK AND MULTIPLE PROTOCOL INTERCHANGES Client UPDATE... TCP/IP network Hop Interchange IPX/SPX network LISTENER.ORA - THE LISTENER.ORA CONFIGURATION FILE RESIDES ONLY ON SERVERS THAT RUN A TNS LISTENER PROCESS. LISTENER.ORA CONFIGURES ONE OR MORE TNS LISTENER PROCESSES. THE FILE DESCRIBES THE NAMES, ADDRESSES, AND DATABASES THAT CORRESPOND TO ONE OR MORE LISTENER PROCESSES. MultiProtocol Interchanges can join different network communities to create one large TNS network that supports client/server applications.

4 UNIQUE DATA STORAGE FOR MULTIMEDIA DATA DATA PARTITIONING Row Row Row BFILE data managed by the server s file system Non-partitioned CUSTOMERS table Partitioned CUSTOMERS table AL,AK,AZ,AR,CA,CO,CT,DC,DE,FL,GA Non-LOB data stored together in a tablespace LOB data stored separately from other row data, but inside database Customers for all states HI,IA,ID,IL,IN,KS,KY,LA,MA,MD,ME MI,MN,MS,MO,MT,NC,ND,NE,NH,NJ NM,NV,NY,OH,OK,OR,PA,PR,RI Locators point to LOB and BFILE data locations s file system SC,SD,TN,TX,UT,VA,VT,WA,WI,WV,WY space space Distributing the storage of primary table data and related multimedia data to different physical locations to reduce disk contention. Oracle8 supports the partitioning of table rows by range. BLOCK THRESHOLDS PCTFREE = 10 PCTUSED = 40 PCTFREE = 10 PCTUSED reached, block put back on free list PCTFREE = 10 PCTUSED = 40 PCTFREE = 10 Space reserved for row updates PCTFREE reached, block taken off free list TABLE SPACES TABLESPACE IS A LOGICAL ORGANISATION OF DATA WITHIN AN ORACLE DATA BASE THAT CORRESPOND TO ONE OR MORE PHYSICAL DATA FILES Data Files PCTUSED = 40 PCTUSED = 40 Oracle removes a data block from a free list when it becomes PCTFREE full. ORACLE returns the block to a free list when it becomes PCTUSED full. CREATE TABLE SALES.ORDERS (.COLUMN SPECIFICATIONS ) PCTFREE 20 PCTUSED 60 ; TRANSACTION ENTRIES spaces INTRANS MAXTRANS SETTINGS DEFAULTS FOR OBJECT STORAGE Each tablespace in an Oracle database physically stores its data in one or more associated data files. WHEN YOU CREATE A NEW DATABASE OBJECT SUCH AS TABLE OR AN INDEX, ORACLE STORES THE DATABASE OBJECT WITHIN THE TABLESPACE OF YOUR CHOICE IF NO INDICATION OF TABLESPACE CHOICE, IT STORES THE OBJECT IN YOUR ACCOUNT DEFAULT TABLESPACE spaces Datafiles SYSTEM TABLE SPACE EVERY ORACLE DATABASE HAS ATLEAST ONE TABLESPACE WHEN YOU CREATE A NEW ORACLE DATABASE, YOU MUST INDICATE THE NAMES THE SIZES OTHER CHARACTERISTICS OF DATA FILES THAT MAKE UP THE PHYSICAL STORAGE FOR THE SYSTEM TABLESPACE ORACLE USES THE SYSTEM TABLESPACE FOR : DATA DICTIONARY SOURCE & COMPILED CODE OF PL/SQL VIEWS, OBJECT TYPE SPECIFICATIONS OTHER TABLESPACES SYSTEM space TEMP space ROLLBACK space ACCOUNTING space ACCOUNTING_INDEX space MANUFACTURING space MANUFACTURING_INDEX space

5 DATA FILES A TABLESPACE S NUMBER OF DATA FILES USE OF DATA FILE SPACE COALESCING FREE SPACE IN A TABLESPACES DATA FILES space space Coalesce space YOU CAN ADD ONE OR MORE NEW DATA FILE REMAINS CONSTANT YOU CAN MANUALLY RESIZE ONE OR MORE OF THE EXISTING DATA FILES IN THE TABLESPACE YOU CAN CONFIGURE ONE OR MORE OF THE DATA FILES IN THE TABLE SPACE TO AUTOMATICALLY EXTEND WHEN THE TABLESPACE BECOMES FULL AND REQUIRES MORE SPACE ON LINE & OFF LINE DATA FILES CONTROL FILES Free space Used space DATA FILE SIZE IN GENERAL THE SIZE OF DATA FILE REMAINS CONSTANT CONTROL FILES INCLUDE THE NAME OF DATABASE AS WELL AS THE NAMES AND LOCATION OF ALL FILES ASSOCIATED WITH THE DATABASE CONTROL FILES ALSO KEEPS TRACK OF INTERNAL SYSTEM INFORMATION TO LOG THE CURRENT PHYSICAL STATE OF THE SYSTEM, INCLUDING INFORMATION ABOUT TABLESPACES, DATA FILES AND SYSTEM BACKUPS SEGMENTS, EXTENTS & DATA BLOCKS ROLL BACK SEGMENTS DATA & INDEX SEGMENTS Data Block TEMPORARY SEGMENTS TEMPORARY TABLESPACES Data Segment Extents Transaction UPDATE sales.customers SET zipcode = WHERE id = 1; Rollback Segment Log old zipcode in rollback segment Transaction UPDATE sales.customers SET zipcode = WHERE id = 1; ROLLBACK; Rollback Segment THE SYSTEM ROLL BACK SEGMENT MULTIPLE ROLLBACK SEGMENT ON LINE & OFF LINE ROLLBACK SEGMENTS PUBLIC & PRIVATE ROLLBACK SEGMENT Restore old zipcode from rollback segment OBJECT STORAGE SETTINGS TABLESPACE PLACEMENT CREATE TABLE ROLLBACK SEGMENT rbseg_10 TABLE SPACE rbseg IF YOU DO NOT MENTION TABLESPACE SPECIFICATION, ORACLE CREATES THE SEGMENT IN THE SYSTEM TABLESPACE EXTENT SETTINGS CREATE TABLE SALES.CUSTOMERS (.COLUMN SPECIFICATIONS.) STORAGE ( INITIAL 500K NEXT 500K MINEXTENTS 1 MAXEXTENTS 10 PCTINCREASE 50 ); DATA BLOCK SETTINGS FREE LIST SETTINGS CREATE TABLE SALES.CUSTOMER_NAME ON SALES.CUSTOMER ( LASTNAME, FIRSTNAME ) STORAGE (..OTHER STORAGE OPTIONS.. ) FREELIST GROUP2 FREELIST 2 ); DATA BLOCKS DATA BLOCK ALLOCATION DATA BLOCK AVAILBILITY & FREE LIST Free List Free List Free List Data Block Data Block Data Block INSERTs... DELETEs... A data block going on an off and object s free list, depending on how full it is

6 ROW CHAINING & DATA BLOCK SIZE Parallel Processing Data Blocks Chained row Rows fit in a single block Storing pieces of a row in a chain that spans multiple data blocks Parallel Processors - The database query is divided into logical components that can be run on MP. Oracle Parallel query option uses this. In Recent years, MP - Multi Processors SMP - Symmetrical Multi Processors MPP - Massively Parallel Processors Parallel Processing Parallel Option - Even a full table scan can be distributed among separate s Parallel Option - Creates a real time copy of the oracle instance and database on one or more file servers, or nodes of a network. Hot Stand-by real time copy Distributed Option - Joining two or more remote DBs Data Replication Option 64-bit option INTRODUCTION TO PARALLEL PROCESSING UNIPROCESSOR VERSUS MULTIPROCESSOR COMPUTERS COMPUTER SPLITS ONE JOB INTO SUBTASKS AND THEN PROCESS THEM IN PARALLEL USING MULTIPROCESSORS TO REDUCE COMPLETION TIME SHARED MEMORY SYSTEMS Shared Memory Shared Disks A Shared Memory System Tightly coupled processors SHARED DISK SYSTEMS SHARED NOTHING SYSTEMS Private Memory Distributed lock manager Private Memory Private Memory Private Memory Private Memory Private Memory Shared Disks A Shared Disk System Private Disks A Shared Nothing System

7 PROCESSING SQL IN PARALLEL PARALLEL SQL PROCESSING SERIAL PROCESSING SELECT column1, column2 FROM table1, table2 WHERE columnx = columny ORDER BY column1 SELECT column1, column2 FROM table1, table2 WHERE columnx = columny ORDER BY column1 1 2 Join Results One processor performs all work A SQL request executed on a multiprocessor computer using serial processing rather than parallel processing Idle s Slow completion time 1 Join Results 2 All processors share the workload Fast completion time A SQL request executed on a multiprocessor computer using parallel processing PARALLEL SQL PROCESSING ARCHITECTURE DATA PARTITIONING AND PARALLEL SQL PROCESSING SELECT... coordinator Other queries SELECT * FROM orders ORDER BY ord_id ORDERS servers 6 Disk I/O bottleneck shows completion time Pool of available query servers Oracle s parallel processing architecture Results Parallel SQL processing without partitioned data create pipelined parallelism. SELECT * FROM orders ORDER BY ord_id Partitioned ORDERS ORACLE S PARALLEL SERVER OPTION - MULTIPLE INSTANCES FOR HIGH AVAILABILITY WHAT IS PARALLEL DATABASE ACCESS? Applications instance instance Applications 12 Results Parallel SQL processing can perform best when you partition large tables and indexes Fast completion time Oracle database A Parallel server allows multiple instances of Oracle to access the same database concurrently.

8 SHARED DATABASE ACCESS MECHANISM ORACLE S CONCURRENCY AND CONSISTENCY MECHANISMS THREE Cs CONTENTION - CONTENTION HAPPENS WHEN TWO USERS TRY TO ACCESS SIMULTANEOUSLY THE SAME RESOURCE SUCH AS A FILE OR A PRINTER CONCURRENCY - CONCURRENCY HAPPENS WHEN MULTIPLE USERS CAN ACCESS THE SAME RESOURCE AS THOUGH EACH USER HAS ACCESS TO THE RESOURCE IN ISOLATION. CONCURRENCY IS HIGH WHEN A USER NOTICES NO APPARENT WAIT TO ACCESS THE SHARED RESOURCE. CONVERSELY, CONCURRENCY IS LOW WHEN A USER MUST WAIT A NOTICEABLE PERIODS OF TIME TO ACCESS THE SHARED RESOURCE. CONSISTENCY - CONSISTENCY HAPPENS WHEN A USER ACCESSES A SHARED RESOURCE AND THE RESOURCE EXHIBITS THE SAME CHARACTERISTICS AMONG OPERATIONS ORACLE S LOCKING MECHANISM AUTOMATIC AND EXPLICIT LOCKING LOCK LEVELS SHARED LOCKS SHARED LOCK ON A DATABASE RESOURCE GIVES A TRANSACTION SHARED ACCESS TO THE RESOURCE SHARED LOCK ALLOW FOR HIGH DEGREES OF TRANSACTION CONCURRECY Transaction 1 Shared lock Exclusive lock Exclusive lock Row # 1 Row # 2 Row # 3 Row # 4 Row # 5 Row # 6 Row # 7. Transaction 2 Shared lock Exclusive lock Exclusive lock Shared and exclusive locks allow for more and less concurrency among database operations. DML LOCKS ROW LOCKS UPDATE SALES.CUSTOMERS SET.. WHERE LAST_NAME = ELISON SELECT * FROM SALES.CUSTOMERS WHERE ZIPCODE = FOR UPDATE NOWAIT; TABLE LOCKS LOCK TABLE CUSTOMERS IN EXCLUSIVE MODE NOWAIT; DEAD LOCKS Transaction 1 Transaction 2 DDL LOCKS DEADLOCK RESOLUTION LOCK ESCALATION QUERIES AND LOCKING EXCLUSIVE DDL LOCKS SHARED DDL LOCKS PARSE LOCKS INTERNAL LATCHES MULTIVERSIONING Has lock Waiting for lock Row # 1 Row # 2. Waiting for lock Has lock SYSTEM CHANGE NUMBER Two transactions in a deadlock CONTROLLING DATABASE ACCESS USERS MANAGEMENT AND AUTHENTICATION USERS AUTHENTICATION PASSWORD AUTHENTICATION OPERATING SYSTEM AUTHENTICATION GLOBAL USERS AUTHENTICATION A USERS S DEFAULT TABLESPACE A USERS S TEMPORARY TABLESPACE LOCKED AND UNLOCKED USER ACCOUNTS PRIVILLEGE MANAGEMENT SYSTEM PRIVILEGES OBJECT PRIVILEGES GRANTING AND REVOKING PRIVILEGES PRIVILEGE MANAGEMENT WITH ROLES PRE-DEFINED DATABASE ROLES ENABLES AND DISABLES ROLES DEFAULT ROLES ROLE AUTHENTICATION RESOURCE LIMITATION TABLESPACE QUOTAS RESOURCE LIMIT PROFILES TIME LOGICAL DISK I/O PER SESSION CONCURRENT DATABASE SESSIONS MAX. CONNECT TIME USERS ACCOUNT MANAGEMENT NO.OF CONSEQUITIVE FAILED CONNECTION ATTEMPTS TO ALLOW BEFORE ORACLE LOCKS THE ACCOUNT THE LIFE TIME OF THE ACCOUNT S PASSWORD NO, OF TIMES PASSWORD MUST BE CHANGED THE DEFAULT PROFILE DATABASE AUDITING SELECTIVE AUDITING AUDIT RECORDS AND THE AUDIT TRAIL

9 CONTROLLING DATABASE ACCESS USERS MANAGEMENT AND AUTHENTICATION USERS AUTHENTICATION PASSWORD AUTHENTICATION OPERATING SYSTEM AUTHENTICATION GLOBAL USERS AUTHENTICATION A USERS S DEFAULT TABLESPACES SYSTEM TABLESPACE A USERS S TEMPORARY TABLESPACES SYSTEM TABLESPACE LOCKED AND UNLOCKED USER ACCOUNTS USER LEAVE ORGANISATION AUTOMATICALLY LOCKED ONCE PASSWORD EXPIRED PRIVILLEGE MANAGEMENT CONNECTION TO AN ORACLE DATABASE CREATE SESSION SYSTEM PRIVILEGE CREATE TABLE DELETE OBJECT SYSTEM PRIVILEGES USER THE ABILITY TO PERFORM SOME TYPE OF SYSTEM - WIDE OPERATION THERE ARE 100 PRIVILEGES OBJECT PRIVILEGES USER THE ABILITY TO PERFORM A SPECIFIC TYPE OF OPERATION ON A SPECIFIC DATABASE OBJECTS SUCH AS TABLE, VIEW OR STORED PROCEDURES ETC. INSERT, EXECUTE, SELECT, UPDATE, DELETE GRANTING AND REVOKING PRIVILEGES PRIVILEGE MANAGEMENT WITH ROLES PRE - DEFINED DATABASE ROLES CONNECT, RESOURCE, DBA, SELECT_CATALOG_ROLE DELETE_CATALOG_ROLE USER DEFINED ROLES SQL STATEMENT ORIENTED RESOURCE LIMITATION TABLESPACE QUOTAS USER CANNOT CREATE OBJECTS IN A TABLESPAEC UNLESS THE USER HAS A QUOTA FOR THE TABLESPACE RESOURCE LIMIT PROFILES TIME LOGICAL DISK I/O PER SESSION CONCURRENT DATABASE SESSIONS MAX. CONNECT TIME USERS ACCOUNT MANAGEMENT DATABASE AUDITING NO. OF CONSEQUITIVE CONNECTION ATTEMPTS TO ALLOW BEFORE ORACLE LOCKS THE ACCOUNT THE LIFE TIME OF THE ACCOUNT S PASSWORD NO. OF TIMES PASSWORD MUST BE CHANGED THE DEFAULT PROFILE SELECTIVE AUDITING AUDIT RECORDS AND THE AUDIT TRAIL