Database Outsourcing Experts

Oracle 10g release 1

Administration

SYSAUXThis new tablespace sits alongside the SYSTEM tablespace and serves the purpose of keeping system-related schemas out of the SYSTEJM tablespace. This includes AWR data, Log Miner data, Streams, Oracle Text and Oracle Spatial. You can also put any of your own schemas in there as you see �t.

Automatic Shared Memory Management (ASMM)Oracle have taken the memory management features introduced in Oracle 9i a step further by introducing the SGA_TARGET parameter. This parameter governs the SHARED_POOL_SIZE, DB_CACHE_SIZE & JAVA_POOL_SIZE parameters, with the database automatically resizing them as it sees �t. With the use of an sp�le, SGA_TARGET can be decreased or increased within the limits of SGA_MAX_SIZE without the need for a database restart.

Automatic Workload Repository (AWR)The AWR replaces the Statspack utility, a vital DBA tool from Oracle 8i & 9i. Unlike Statspack, the AWR runs automatically in the background, by default gathering hourly snapshots of system data and keeping 7 days worth on-line. More statistical data is collected than before and easy to read HTML reports can be produced. In addition, you can create performance baselines against which you can compare database activity.

Data DumpAlthough import and export still exist in 10g, Oracle has produced a signi�cantly enhanced version of the tools (impdp & expdp), collectively known as Data Pump. Using similar interfaces to the old export and import you can now load and unload data at dramatically faster speeds. In addition you can detach from a long-running Data Pump job session and re-attach to it from elsewhere and continue to interact with it. Many extra features have also been added, including dynamic transformation of data storage parameters and tablespace locations. Another nice feature is that the contents of single table dump �les exported with expdp can be viewed as external tables using a new external table driver.

DBMS_FILE_TRANSFER PackageThis new package can be used to copy binary �les around, both on the local server and to remote servers. As is usual these days, directory objects within the database facilitate this process.

Direct 8 & 8i Upgrade ProcedureYou can directly upgrade your 8.1.7 or 8.0.6 database to 10g Release 1 using a single script.

Extended Database AuditingWhen database-based auditing is switched on, extra information such as SQL statements can be written to the AUD$ table.

More Archiving DestinationsYou can now have 5-10 archive log destinations speci�ed in the parameter �le.

Multiple Block SizeTablespaces can be created with non-standard block sizes (i.e. block sizes other than that speci�ed by the DB_BLOCK_SIZE initialisation parameter). To use this feature you must specify a sub-cache for that block size by using the appropriate DBA_(n)K_CACHE_SIZE initialisation parameter.

Optimizer Changes & Statistics GatheringAlthough it remains for backwards compatibility, the Rule Based Optimizer has been shelved and is no longer supported. This makes it more important than ever to have current and accurate statistics on all your data and 10g provides an automatic statistics gathering job to gather statistics nightly. Tables now all have monitoring on by default and so only stale or

01 02 03 04 05 06 07

Database Outsourcing Experts

Oracle 10g release 1

Administration

Resumable Space AllocationThis feature was introduced in Oracle 9i and could be set at session level or as part of an import command. 10g introduces the resumable_timeout init.ora parameter meaning the feature is turned on at the database level. It can also be altered via the alter system command.

Security EnhancementsThe new DBMS_CRYPTO package allows data to be encrypted right down at the table data level using most kinds of encryption such as RSA and MD5 and so on. Further improvements to the Fine Grained Auditing feature and Virtual Private Databases (DBMS_RLS) mean data can be monitored and secured at an even more sophisticated level than before.

Shared ServerThis is now even easier to use with dispatchers that start automatically and easily changeable settings via alter system commands.

Temporary Tablespace GroupsAs the name suggest you can now assign any number of temporary tablespaces to a tempo-rary tablespace group and assign the group as a user’s temporary tablespace. This enables better distribution of temporary segment usage and can be of particular bene�t in data warehouses where very large sort or hash joins are written to disk.

Web-based Enterprise Manager and Grid ControlThe old enterprise manager tool has been completely revamped and turned into a web-based management tool. As well as all the usual features you can now access all of the aforementioned workload repository and advisory features through the same interface and completely manage all aspects of database administration. Grid Control lets you manage databases and application services across RAC environments.

Automatic Database Diagnostics Monitor (ADDM) & the Advisor Framework10g provides the DBMS_ADVISOR package to help tune many aspects of database perfor-mance including query tuning, undo tuning, hot segment identi�cation & materialized view tuning. With regards to SQL tuning, the advisor can work out the best optimizer plan and you can save this as a pro�le for the statement so it is always used. DBMS_ADVISOR underpins the ADDM which, like the AWR is constantly running in the background. You can run an ADDM report between two snapshots to see what performance bottlenecks have been identi�ed and any auto-generated advice about how to resolve them.

Automatic Storage Management (ASM)With this new feature, Oracle can now take over the task traditionally performed by volume managers (e.g. Veritas) and manage the �lesystems on your disks directly. A special Oracle instance resides on the server which transparently manages the disks. By presenting a series of raw disks to the Oracle ASM instance, Oracle can manage disk redundancy and data striping across these disks to provide best performance. In addition Oracle can dynamically rebalance disks as you new disks to the server. However, if you prefer to have something like disk RAID pre-con�gured, you can just present the RAID volumes to ASM and it will only manage the �lesystem and the database �les. ASM uses an extension of Oracle Managed Files syntax to locate and name database �les. As well as core database �les, archivelogs and other backup �les can also reside on ASM.

Automatic Undo RetentionThe init.ora parameter undo_retention is now a minimum value rather than an absolute value for undo retention. In 10g, Oracle will take this minimum and tune undo retention up and down above it in an e�ort to ensure that the longest running queries running on the database will not be susceptible to ORA-01555 errors.

01 02 03 04 05 06 07

Database Outsourcing Experts

Oracle 10g release 1

Administration

Big�le TablespacesThis special kind of tablespace has a single data�le that can be anywhere in size up to 128TB (depending on the block size speci�ed for the tablespace). This simpli�es management and you can use alter tablespace commands where you would normally use “alter database data�le” commands to modify the �le, e.g. change its size or set autoextend. This kind of tablespace is most useful in data warehouses as it allows for the creation of very large databases.

Database SchedulerThe new DBMS_SCHEDULER package signi�cantly enhances the functionality of DBMS_JOB. The scheduler can run scripts external to the database and jobs can have dependencies so that they will be run in sequence and the sequence halted if one fails. Job windows can be created so that a job will start when the window opens and will terminate if still running when the window closes – ideal for limiting overnight schedules.

Default User TablespaceOracle 9i introduced the default temporary tablespace and 10g takes this step further by introducing the ability to set a default user tablespace as part of the alter database command.

Drop Database / Rename TablespaceThese two new SQL commands provide handy solutions to old problems. A tablespace can now easily be renamed with a single rename command. An entire database instance and all its �les can be dropped with the drop database command. This is especially useful if you are using Automatic Storage Management as in 10g release 1 you cannot directly interact with ASM �les. Furthermore, from RMAN you can issue the “drop database including backups” command to delete everything related to the database.

EZ Connect FacilityYou can now connect to database without any of the traditional con�guration �les (such as sqlnet.ora and tnsnames.ora) by specifying a JDBC-style connect string that includes server and listener port information.

Multi-tier Materalised ViewsYou can now build updateable materialized views on top of other updateable materialized views. This provides the ability to create complex branched replication environments, e.g. for regional o�ces.

Online Segment ShrinkThe days of having to rebuild an object to reset its high watermark are now over with the online segment shrink feature. ALTER TABLE commands can be run to compact a table and reset its high watermark, thus freeing up any unused space within each segment. This feature does not work with LOBS, XML and other user-de�ned data types.

Recycle BinAs part of enhancements to Oracle’s Flashback features, each tablespace now has a recycle bin and objects are moved there after they are dropped unless you speci�cally use the PURGE keyword as part of the drop statement. If you don’t need it the recycle bin can be turned o� with a hidden parameter.

Resource Manager EnhancementsEnhancements here include a Session Timeout feature and the ability to switch back to your original consumer group after a switch for other reasons. In addition you can con�gure the database to automatically assign a consumer group to a session based on certain characteris-tics.

RMAN - Data�le Format Conversion

01 02 03 04 05 06 07

Database Outsourcing Experts

Oracle 10g release 1

Administration

Server AlertsThe DBMS_SERVER_ALERT package allows you to monitor and automatically generate alerts within the database. Things you can monitor include tablespace usage, open cursors, database wait time and blocked sessions.

Skip Unusable IndexesThe new init.ora parameter skip_unusable_indexes prevents errors being returned when a query is issued against a table that tries to use an unusable index. Instead the index is ignored and the query goes ahead.

UTL_MAIL PackageThis new package allows you to send mails from the database using very simple commands, instead of the many commands that used to be necessary with UTL_SMTP. All you need to do is set the smtp_out_server init.ora parameter to point to your mail host and port number.

Application Programming

Binary Float/Double Data TypesThese new �oating point data types are more e�cient than the number data type and are more widely accepted in the �eld of computing.

DBMS_LOB EnhancementsTwo new procedures LOADBLOBFROMFILE and LOADCLOBFROMFILE allow you to import external �le content directly into LOB �elds.

Oracle Data Provider.net (ODP.net)ODP.net is a new programmatic environment that implements a data provider for Oracle Database. It uses APIs native to Oracle Database to o�er fast and reliable access from any .NET application to database features and data. ODP.NET also uses and inherits classes and interfaces available in the Microsoft .NET Framework Class Library.

Terabyte LOB SupportJDBC, OCI & PL/SQL can now all handle terabyte LOBs.

Case & Accent Insensitive QueriesThe new NLS_SORT parameter can be used in queries to ignore case and accents when sorting.

Expression FilterOracle Expression Filter lets you store conditional expressions in a column that you can use in the WHERE clause of a database query.

Regular ExpressionsThese can now be used in SQL though the new REGEXP_LIKE, REGEXP_INSTR, REGEXP_REPLACE and REGEXP_SUSBTR functions, leveraging this powerful Unix-style

Backup & Recovery

Flash Recovery AreaThis is an area of disk space designed to allow you to keep all your recovery-related database �les in a single location. You set a size for the �ash recovery area although this is a soft limit rather than hard disk limit. Files to go in here are RMAN backup sets and control�le backups; redo log �les; control �les; archivelog �les and �ashback log �les. You can use the RMAN “backup recovery area” command to back up the entire �ash recovery area to tape or another disk.

01 02 03 04 05 06 07

Database Outsourcing Experts

Oracle 10g release 1

Backup & Recovery

Recovery Through ResetlogsThis is now possible using an additional tag in the archive_log_format init.ora parameter. The new %r format command shows which incarnation of the database the log refers to as well as the thread and sequence number.

RMAN - Backup Duration and ThrottlingIt is now possible to con�gure RMAN to terminate a backup after a speci�ed amount of time or to throttle a backup process in order to minimise the load on the server.

RMAN - Channel FailoverIf you are using multiple channels in an RMAN operation, the process can automatically failover between channels if a particular channel encounters an error.

RMAN - Incrementally Updated File Copy BackupsPerhaps one of the best new RMAN enhancements is the ability to just update your backup sets instead of backing up the whole database every night. Provided you have enough disk space to keep your backups online, RMAN can initially create a �le copy backup of the database and then update these copies using available incremental backups every time the “recover copy of database” command is issued.

SYSAUX TablespaceThis new tablespace sits alongside the SYSTEM tablespace and serves the purpose of keeping system-related schemas out of the SYSTEJM tablespace. This includes AWR data, Log Miner data, Streams, Oracle Text and Oracle Spatial. You can also put any of your own schemas in there as you see �t.

Flashback EnhancementsThe �ashback feature introduced in Oracle 9i has been considerably improved in 10g. Having set things up appropriately, �ashback data is written to �ashback logs on the local �lesystem and using these, you can �ashback an entire database to a previous moment in time – much quicker than restoring from a backup and rolling forward with archivelogs. With the aid of the new Recycle Bin feature you can �ashback tables to before they were dropped and even �ashback queries and transactions.

RMAN - Backup Command ChangesThe backup and copy commands have been merged together into just the backup command. To do a �le copy backup you can use the “backup as copy” syntax to over-ride the default creation of backup sets.

RMAN - Binary Compression for Backup SetsRMAN already compresses backups by not backing up unused data blocks but with 10g you can take this even further and apply binary compression to backup sets to further reduce disk usage.

RMAN - Fast Incremental BackupWith the addition of the Block Change Tracking feature, incremental RMAN backups can be done in a fraction of the time of level zero backups. An external �le is con�gured on the server which keeps track of any changed blocks since the last backup, this information is then used to only backup those blocks.

RMAN - Restore FailoverDuring the restore process, RMAN can now automatically failover to a copy of a backup piece if the original is for some reason not available. If no copy can be found then it can fail over to an earlier backup piece and just roll forward with more archivelogs.

RMAN - User-catalogued Backup PiecesOf great relief to many DBAs will be the fact that you can now manually add a backup piece

01 02 03 04 05 06 07

Database Outsourcing Experts

Oracle 10g release 1

Business Intelligence

Asynchronous Change Data CaptureChange Data Capture was introduced in Oracle 9i and is a powerful tool for updating your data warehouse from the source databases. 10g introduces Asynchronous capture, meaning changes captured in the redo logs can be propagated to the warehouse via archive logging, and then applied to the warehouse using Oracle Streams technology.

MERGE Statement ImprovementsIt is no longer necessary to include both the INSERT and UPDATE clauses, only one is needed and Oracle can work out the rest. There is now an optional DELETE clause that can delete rows according to certain criteria. You can now perform conditional inserts using a new WHERE clause.

Partitioning EnhancementsYou can now partition Index Organised Tables (IOTs). Hash partitioned global indexes are also available.

Recovery Through ResetlogsThis is now possible using an additional tag in the archive_log_format init.ora parameter. The new %r format command shows which incarnation of the database the log refers to as well as the thread and sequence number.

Materialized View EnhancementsPartition Change Tracking, introduced in Oracle 9i for range and range-hash partitioned tables, can now be used for all partitioning types. This means that each partition tracks its own changes via materialized view logs and uses the details for a fast refresh. Hierarchical materialized views can now be automatically refreshed in the proper order using DBMS_MVIEW. You can also build materialized views that depend on other views using the “build deferred” clause and let them later be populated via the refresh procedure. As part of the Advisor Framework, the new materialized view advisor (DBMS_ADVISOR.TUNE_MVIEW) has been created to help tune materialized views.

MODEL ClauseThis powerful new clause allows you to perform complex computations and predictions based on current data without the need for excessive joining and UNION clauses. It’s also OLAP compliant and can be used with Oracle OLAP features.

High Availability

Automatic Failover with Data Guard ManagerNot only has the syntax for this tool been greatly simpli�ed, it can now be used to auto-failover a database to the standby. This is done by having a separate server with an Oracle installation on it (and another license fee of course!) which monitors both the live and standby nodes. In the event it loses contact with the live database, the monitor node performs a failover to the standby. When it becomes available again, the old live database is automatically recon�gured to act as a new standby.

Real Application Clusters (RAC)RAC has been radically altered as part of the transition to grid computing. Although the basic concepts remain the same, the components of the clustering software have been brought together and renamed Cluster Ready Services, or CRS. CRS manages cluster database functions including node membership, group services, global resource management, and high availability. As previously mentioned, application services are de�ned within CRS to help enable grid computing. 10g also saw the introduction of Virtual IP Addresses (VIP) to enhance the failover abilities of RAC when nodes go down. Each server has its own VIP address which is registered in DNS. When a node goes down, Oracle can migrate the VIP to another node in the cluster so that connections can still come though. The Database Con�guration Assistant

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01 02 03 04 05 06 07Database Outsourcing Experts

Oracle 10g release 1

High Availability

Support for Recovery Through ResetlogsThe new %r tag in the archive log format means that a standby database can be rolled forward even if a resetlogs has occurred on the primary.

Flashback SupportAs already mentioned you can use the Flashback feature to �ashback a standby database to a point before it was activated and continue to use it as a standby.

log_archive_dest_n new “valid_for” ParameterIn Oracle 9i, con�guring the log_archive_dest_n init.ora parameter to cope with switchovers and switchbacks meant many alert log errors being produced as, for example, the standby destination con�gured on the standby database tried to connect to the live database before the roles were switched over. In Oracle 10g, the new “valid_for” parameter allows you to con�gure an archive destination to only be active when the database is playing a certain role, meaning no more confusing and irrelevant alert log errors.

Real-time Apply EnhancementsIt’s no longer necessary for a log switch to occur to apply data to a standby using the SQL apply method.

The GridThe centrepiece of the publicity surrounding Oracle 10g is the concept of Grid Computing. Real Application Clusters (RAC), the high availability functionality introduced in Oracle 9i, has been completely revamped to provide the backbone for Oracle’s vision of grid computing (inevitably involving trying to make you purchase as many Oracle licenses as possible). By registering database applications as services within the RAC cluster con�guration, you can assign a service to one or more nodes in RAC cluster meaning that behind the scenes Oracle will load balance the application across the nodes, taking advantage of idle CPU on some nodes when others start to become overloaded. The concept extends to the Oracle Applica-tion Server suite of products meaning you can have a complete grid-based and fault tolerant multi-tier application. Central to the management of all this is Grid Control, an enhanced version of the new web-based Oracle Enterprise Manager software that allows you to manage all aspects of your grid.