利用 Oracle Database 12c 实现万无一失的安全性共45页文档

Oracle数据库应用系统的安全性摘要：从开发应用程序的角度出发，深入理解oracle数据库的安全策略。

结合当前的数据加密技术，提出由应用程序开发人员和数据库管理人员共同提高应用系统安全性的新观念，并以提高Oracle数据库应用系统安全性为例加以实现。

关键词：Oracle数据库应用程序安全在一些较大规模的客户/服务器系统中，许多数据库管理员都会遇到由于应用程序的安全漏洞，导致数据库中数据丢失的问题，这时，数据库管理员除了从备份中恢复数据外别无它法。

但是，只要在开发程序时，事先考虑系统的安全问题，便可以提高应用系统的安全性。

以往在开发数据库应用程序时，软件的登录界面大多是直接使用数据用户进入程序的，知道数据拥有用户口令的人就越多，这样他们除了通过应用程序连接数据库外，还可以用许多其它的工具连接数据库，近而可以对该用户所拥有的数据做任意的修改、删除等操作，使其中的数据再无安全可言，而系统却认为其是合法的，因为他是以合法身份进入数据库的。

尽管经常改变数据库的用户密码是为保障数据库系统安全而经常采用的一个基本办法，可对于那些已经将认证用户和密码写在程序中的应用系统，数据库管理员又不能随意地改动该用户的口令，因为一旦口令发生变化，应用程序的开发人员就要重新改写程序中的相关部分，重新进行编译后再下发给各个推广单位，所有这些工作对于客户端多而分散的应用系统而言，工作量大，实际运作极不方便。

针对这一问题，我们提出在开发数据库应用系统时，应结合基础数据库的安全策略，由应用程序开发人员和数据库管理人员来共同提高数据库应用系统的安全性，近而提高数据库的安全性。

1应用技术1.1数据加密技术数据加密技术，是为提高信息系统及数据的安全性、保密性和防止秘密数据被破解所采用的主要技术手段之一。

随着信息技术的发展，网络安全与信息保密日益引起人们的关注。

目前各国除了从法律上、管理上加强数据的安全保护外，还分别在软件和硬件两方面采取措施，促使数据加密技术和物理防范技术不断发展。

Top Oracle Database 12cHigh Availability Innovations A Technical DrilldownWei Hu, Vice President of Development, High Availability Technologies, OracleBest Innovations Make Things Easy▪Any sufficiently advanced technology is indistinguishable from magic - Arthur C. Clarke▪Any technology that is distinguishable from magic is not sufficiently advanced - Gregory Benford▪This talk will give an overview of the new high availability features introduced in Oracle Database 12c▪Then describes some of the internal innovations that make these features powerful and easy to useOracle Database 12c▪Oracle Database 12c introduces significant new HA capabilities that–Drastically cut down planned and unplanned downtime –Eliminate compromises between HA and Performance –Tremendously boost operational productivity▪These take Availability to unprecedented new levels–Next-generation Maximum Availability Architecture (MAA) –Optimized for OracleExtreme AvailabilityOracle Maximum Availability ArchitectureActive Data Guard–Data Protection, DR–Query OffloadGoldenGate–Active-active –HeterogeneousRMAN, Oracle Secure Backup–Backup to tape / cloudActive ReplicaEdition-based Redefinition,Online Redefinition, Data Guard, GoldenGate– Minimal downtime maintenance, upgrades, migrationsRAC–Scalability –Server HAFlashback–Human error correctionProduction SiteApplication Continuity–Application HAGlobal Data Services–Service Failover / Load BalancingOracle Database 12cHigh Availability Key* New Features ▪Application Continuity▪Global Data Services▪Data Guard Enhancements▪RMAN Enhancements▪Flex ASM▪Other HA Enhancements▪GoldenGate Update▪MAA at PayPal▪ *Nearly a hundred new HA features in 12cDatabase outages can cause in-flightwork to be lost, leaving users and applications in-doubt -–User frustration –Cancelled work –Duplicate submissions –Rebooting mid-tiers –Developer painsPre-12c SituationIn-Flight Work: Dealing with OutagesApplication ServersDatabase ServersEnd User▪Replays in-flight work on recoverable errors▪Masks many hardware, software, network, storage errors and outages ▪Supports JDBC-Thin, Universal Connection Pool (UCP), WebLogic Server, 3rd Party Java apps/mid-tiers ▪RAC, RAC One, & Active Data Guard ▪Better end user experienceApplication ContinuityMasks unplanned/planned outages when successfulApplication ServersDatabase ServersEnd UserDatabase RequestReplayedApplication Continuity SubtletiesThe hardest part of replay is deciding when NOT to replay▪Application Continuity minimizes divergence by re-executing SQL at original SCN (when possible) and rebuilding original environment–Stops replay (and returns error) if replayed request returns different result than original (e.g., two users concurrently updating same row)▪Application Continuity does not attempt replay (and returns error) if –Error is not recoverable – e.g., constraint violation–DDLs such as SHUTDOWN ABORT, DROP TABLESPACE are executed–Request has been explicitly disabled for replay – e.g., disbursing money–Failure occurred too long ago – don’t automatically replay a request from yesterday ▪Application Continuity is safe; only replays incomplete requests – Will not pay for the same item twiceafter outagesTransaction GuardPreserve & Retrieve COMMIT Outcome▪Tracks outcome of the last transaction ▪Without Transaction Guard, retry can cause logical corruption▪Transaction Guard allows applications to deal correctly with failures▪Application Continuity uses Transaction Guard▪Transaction Guard also available for applications that do not use Application ContinuityApplication Continuity I nternalsOracle Database 12cHigh Availability Key New Features▪Application Continuity▪Global Data Services▪Data Guard Enhancements▪RMAN Enhancements▪Flex ASM▪Other HA Enhancements▪GoldenGate UpdateDatabases in Replicated EnvironmentsChallenges▪Maximum Availability ArchitectureActive Data Guard and GoldenGate with RAC▪Want to optimize utilization ofActive Data Guard and GoldenGate databases–Efficiently use all availabledatabases–Automated load balancing and faulttolerancePrimary Active Standby Active StandbyGlobal Data Services•Extends RAC-style service failover, loadbalancing (within and across datacenters), and management capabilities to a set of replicated databases•Takes into account network latency,replication lag, and service placement policies•Achieve higher availability, improvedmanageability and maximize performanceLoad Balancing and Service Failover for Replicated Databases▪Reporting client routed to ‘best’ database–Based on location, response time, data, acceptabledata lag–Reports will automatically run on least loaded server▪Reporting client failover–If preferred database not available, will route toanother database in same region or a remote database▪Global service migration–Automatically migrates services based onfailover/switchover - if primary database is down, start Call Center service on the new primaryActive Data Guard ExampleActive Data GuardReporting ServiceCall Center Service▪Call Center Client connections andrequests transparently routed to the closest / best database–Runtime load balancing metrics give client real-timeinformation on which database to issue next request▪If a database fails, its global services arerestarted on another replicaGoldenGate ExampleGoldenGateCall Center ServiceLoad Balancing is Very ComplicatedGlobal Data Service (GDS) Load Balancing▪Supports connect-time and run-time (per-request) load balancing▪Load balancing is easy if all your machines and workload are uniform–GDS supports heterogeneous environment – RAC + non-RAC, powerful and less powerful machines (important since some customers have less powerful machines for DR)▪Load balancing is NOT equal load on all machines–Instead, GDS minimizes average response time across all requests–If database 1 much faster than database 2, then 100% of requests might go to machine database 1–Sometimes, request to lightly-loaded database in remote region might complete faster than request to heavily loaded database in local region–Equalization of average response time done for all clients in each region (remote requests expected to be longer) ▪Load balancing must balance responding rapidly to changing workloads and avoiding oscillations▪Uses internal database metrics, does not blindly rely on external metrics–More accurate (factors out network variability), handles workload generated external to global services, & handles planned shutdown caseGlobal Data Services: SummaryGlobally Replicated, High Availability Architecture••• GSM - Global Service ManagerLocal StandbyLocal StandbyData Center #2 EMEAAPACGuardData GuardPrimaryLocal StandbyActiveData GuardGDSCTLGDS Catalog PrimaryGDS Catalog StandbyMasterOracleGoldenGate Active GuardSALES POOL (sales_reporting_srvc, sales_entry_srvc)HR POOL(hr_apac_srvc, hr_emea_srvc)All GDS client databases connected to all GSMsMasterRemote StandbyReader FarmActive Data GuardGlobal Service ManagersGlobal Service ManagersOracle Database 12cHigh Availability Key New Features▪Application Continuity▪Global Data Services▪Data Guard Enhancements▪RMAN Enhancements▪Flex ASM▪Other HA Enhancements▪GoldenGate UpdateZero Data Loss ChallengeThe longer the distance, the larger the performance impactSynchronous Communication Leads To Performance Trade-OffsPrimaryStandbyCommitCommit AckNetwork SendNetwork AckStandbyData Guard Async – TodaySome Data Loss Exposure Upon DisasterZero Data Loss For Async Deployments▪Far Sync: light-weight Oracle instance: standby control file, standby redo logs, archived redo logs, no data files▪Receives redo synchronously from primary, forwards redo asynchronously in real-time to standby▪Upon Failover: Async standby transparently obtains last committed redo from Far Sync and applies: zero data loss failover▪Second Far Sync Instance can be pre-configured to transmit in reverse direction after failover/switchover▪Terminal standbys required to be Active Data Guard StandbysPrimaryStandbyFar SyncInstanceStandbyFar SyncInstanceActive Data Guard Far SyncMuch work done to make things work ‘like magic’▪Looks just like SYNC. So Fast Start Failover (FSFO) works – automatic, zero data loss failover to far destination▪If Far Sync instance fails, can failover to another Far Sync (recommended), or go into async mode directly to standby (using remote alternate log_archive_dest_x)▪Sophisticated logic to make failovers seamless–When primary dies, Far Sync keeps track of state of async connections to terminal standby to ship the exact redo needed for zero data loss–Works with RAC (multiple threads of redo)▪Smart gap resolution – if the primary is missing redo, it can fetch from Far Sync instance. Far Sync instance will transparently fetch from primary & forward to standbyActive Data Guard Far SyncSummary of Benefits▪Best data protection, least performance impact▪Low cost and complexity▪Best way to implement a near DR + Far DR model▪Relevant to existing Data Guard ASYNC configurations▪Data Guard Failover? No Problem! Just do it – No Data Loss!Active Data Guard Real-Time CascadingEliminates Propagation DelayPrimary▪In 12.1, Standby 1 forwards redo to Standby 2 in real-time, as it isreceived: no propagation delay for a log switch▪Standby 2 (Active Data Guard Standby) is up-to-date for offloadingread-only queries and reports▪In 11.2, Standby 1 waits till log switch before forwarding redo fromarchived logs to Standby 2Data Guard Fast SyncReduced Primary Database Impact for Maximum AvailabilityLogsStandbyRedoLogsCommitCommitAcknowledge▪For SYNC transport: remote siteacknowledges received redo beforewriting it to standby redo logs▪Reduces latency of commit on primary▪Better DR – increased SYNC distance▪If network round-trip latency less thantime for local online redo log write,synchronous transport will not impactprimary database performance▪Can use Fast Sync from Primary to FarSync , and Fast Sync works with FSFO CommitCommitAcknowledgeAcknowledgereturned on receiptLogsStandbyRedoLogsData GuardOther New Features in Oracle Database 12cOracle Database 12cHigh Availability Key New Features▪Application Continuity▪Global Data Services▪Data Guard Enhancements▪RMAN Enhancements▪Flex ASM▪Other HA Enhancements▪GoldenGate UpdateFine-grained Table Recovery From Backup▪Simple RECOVER TABLE command torecover one or more tables (mostrecent or older version) from an RMANbackup▪Eliminates time and complexityassociated with manual restore, recover& export–Enables fine-grained point-in-timerecovery of individual tables instead ofthe contents of the entire tablespaceRMANBackupsCross-Platform Backup & Restore▪Simplifies procedure for platform migration▪Minimize read-only impact with multiple incremental backupsSimplified Platform MigrationSource Database (AIX)Backup to Disk/Tape (data files, optional endian conversion,metadata export)Restore Backup (optional endian conversion, metadata import)Destination Database (Solaris)▪Backup and recover specific pluggable databases with new PLUGGABLE DATABASE keywords:RMAN> BACKUP PLUGGABLE DATABASE <PDB1>, <PDB2>;▪Familiar BACKUP DATABASE command backs up CDB, including all PDBs ▪PDB Complete Recovery–RESTORE PLUGGABLE DATABASE <PDB>; –RECOVER PLUGGABLE DATABASE <PDB>;▪PDB Point-in-Time Recovery–RMAN> RUN {–SET UNTIL TIME 'SYSDATE-3'; –RESTORE PLUGGABLE DATABASE <PDB>; –RECOVER PLUGGABLE DATABASE <PDB>;–ALTER PLUGGABLE DATABASE <PDB> OPEN RESETLOGS; }▪Familiar RECOVER DATABASE command recovers CDB, including all PDBsPluggable Database Backup & RestoreFine-Grained Backup & Recovery to Support ConsolidationOracle Database 12cHigh Availability Key New Features▪Application Continuity▪Global Data Services▪Data Guard Enhancements▪RMAN Enhancements▪Flex ASM▪Other HA Enhancements▪GoldenGate UpdateAutomatic Storage Management (ASM) OverviewASM Cluster Pool of StorageDisk Group BDisk Group A Shared Disk GroupsWide File StripingOne to OneMapping of ASM Instances to ServersASM InstanceASM DiskRAC ClusterNode4Node3Node2Node1Node5ASMASM ASM ASMASMASM InstanceDatabase InstanceDB ADB A DB BDB BDB CDB BCurrent StateFlex ASM: Eliminate 1:1 Server MappingNew: ASM Storage Consolidation in Oracle Database 12cASM Cluster Pool of StorageDisk Group BDisk Group A Shared Disk GroupsWide File StripingDatabases share ASM instancesASM InstanceDatabase InstanceASM DiskRAC ClusterNode5Node4Node3Node2Node1Node5 runs as ASM Client to Node4Node1Node2 Node4Node2 runs as ASM Client to Node3 ASM ASM ASMASM InstanceDB ADB A DB BDB BDB CDB BFlex ASM: Supporting Oracle Database 11gPrevious Database Versions Will Host Local ASM InstanceASM Cluster Pool of StorageDisk Group BDisk Group A Shared Disk GroupsWide File StripingDatabases share ASM instancesASM InstanceDatabase InstanceASM DiskRAC ClusterNode5Node4Node3Node2Node1ASM ASM ASMDB ADB A DB BDB BDB C DB BASMASM11.2DB11.2DBOracle Database 12cHigh Availability Key New Features▪Application Continuity▪Global Data Services▪Data Guard Enhancements▪RMAN Enhancements▪Flex ASM▪Other HA Enhancements▪GoldenGate UpdateOther HA EnhancementsOracle Database 12cHigh Availability Key New Features▪Application Continuity▪Global Data Services▪Data Guard Enhancements▪RMAN Enhancements▪Flex ASM▪Other HA Enhancements▪GoldenGate UpdateNote: A single DR copy may be multi-purposed for any combination of the use cases describedData Guard Redo TransportSYNC or ASYNCOracle DatabaseOracle Active Data GuardReal-Time Data Protection and AvailabilityStandby First Patching, Exact copy of primary Query & Report OffloadOpen Read-Only Snapshot StandbyConvert to Test Database(open read-write)Single Command Refresh of primary Offload RMAN Backups of primary Far Sync, Database Backup Appliance, GoldenGateExact copy of primarySource for thin snaps/clones Exact copy of primary Extract offload, source for GoldenGate ALO modeOracle & Non-OracleMessage BusOracle Database12c *Oracle GoldenGate 12c*Low-Impact, Real-Time Data Integration & Transactional ReplicationData IntegratorNew DB/ HW/OS/APP Fully Active Distributed DBReporting Database DataWarehouse ODSZero Downtime Upgrade& Migration Query & Report Offloading Data Synchronization within theEnterprise Real-time BI, OperationalReporting, MDMEvent Driven Architecture, SOAActive-Active High AvailabilityMessage BusGlobal Data Centers Logical Copy of Primary Disaster Recovery for Non-Oracle Databases *: GoldenGate 12c for Oracle Database 12c will be available in CY2013GoldenGate Zero Downtime Migration/Upgrade Seamless Migration and Upgrades to Oracle Database 12c* •Consolidate/migrate/maintain systems withoutdowntime•Minimize risk withfailback option•Validate data beforeswitchover•Use Active-Active replication for phased user migrationERP Oracle ERP*: GoldenGate 12c for Oracle Database 12c will be available in CY2013 Oracle10.2CRM11.2DWOracle GoldenGate for Active-Active DatabasesIncrease ROI on Existing Servers & Synchronize Data•Utilize secondarysystems for transactions •Enable continuousavailability during unplanned & planned outages•Synchronize data acrossglobal data centers •Use intelligent conflictdetection & resolution*: GoldenGate 12c for Oracle Database 12c will be available in CY2013Oracle 10.2 App2Oracle 11.2 App3Non-Oracle AppHeterogeneous Bi-DirectionalOracle Database 12c▪Oracle Database 12c offers a tremendously sophisticatedset of high availability (HA) capabilities▪These capabilities–Further reduce downtime–Significantly improve productivity–Eliminate traditional compromisesExtreme Availability: SummaryResources▪OTN HA Portal:/goto/availability▪Maximum Availability Architecture (MAA):/goto/maa▪MAA Blogs:/maa▪Exadata on OTN:/technetwork/database/exadata/index.html▪Oracle HA Customer Success Stories on OTN:/technetwork/database/features/ha-casestudies-098033.htmlKey HA Sessions and Demos by Oracle DevelopmentMonday, 23 September Moscone South10:45a Oracle DB 12c—Eng’d for Clouds and Big Data, North D1:45p Oracle Exadata—What’s New and What’s Coming, 1033:15p Top Oracle DB 12c HA Innovations - A Technical Drill-down, 103 4:45p RMAN in Oracle DB 12c: New Features and Best Practices, 102 4:45p Compression and Performance in Oracle Database 12c, 104Tuesday, 24 September Moscone South10:30a Always Available: Oracle Exadata and Oracle MAA, 10210:30a Oracle RAC 12c Best Practices, 10412:00p A Revolutionary New Way to Do DB Backup and Recovery, 102 12:00p Oracle Flex Cluster: Optimized Resource Mgmt. for Cloud, 104 12:00p Storage Optimization with Oracle Database 12c, 3013:45p Oracle DB 12c Best Practices for Data Availability andDisaster Protection, 1025:15p Optimize Oracle Active Data Guard and Oracle GoldenGate:Wednesday, 25 September Moscone South10:15a Best Practices for Integrating GoldenGate w/ Act. Data Guard, 104 11:45a The Next Big Thing!, 10311:45a Best Practices for Oracle Exadata Backup and Recovery, 20011:45a Cloning and Snapshots with Oracle Database 12c, 1021:15p Redefining Backup and Recovery with Oracle Eng’d Systems, 200 3:30p Oracle Active Data Guard: Next-Generation Data Protection, 103 5:00p Oracle Exadata Storage Availability Best Practices, 2005:00p Integrated Apply: Scalable Replication with GoldenGate, North 131 5:00p Exadata Planned Maintenance for Zero Downtime, Westin Metro. IThursday, 26 September Moscone South11:00a Oracle Database-Aware Flash: Maximizing Performance andAvailability for Your Database, 2362:00p Oracle MAA Best Practices for the Oracle Multitenant Option, 102 2:00p Maximize Availability by Using DB Services with Oracle RAC, 103。

ORACLE数据库安全解决方案
《ORACLE数据库安全解决方案》
ORACLE数据库安全一直是企业数据管理的重要环节，因为
它存储了公司的核心信息，包括客户资料、员工信息和财务数据等。

为了保护这些关键数据，企业需要采取一系列严密的安全措施，以防止未经授权的访问和数据泄露。

在ORACLE数据库安全的解决方案中，加密技术被广泛应用，它通过将敏感数据转化为密文，以保护数据的机密性和完整性。

此外，数据库审计和监控也是关键的安全措施，它可以追踪数据库的所有活动，并通过实时警报和日志记录来识别潜在的安全威胁。

另外，访问控制也是ORACLE数据库安全解决方案中的核心
组成部分，它可以通过角色和权限管理来限制用户对数据库的访问权限，从而降低内部和外部威胁的风险。

此外，强化密码策略和多因素身份认证也是保护数据库安全的有效方法，它可以防止未经授权的用户登录数据库，并提高登录安全性。

除了上述措施之外，数据库备份和恢复也是保护ORACLE数
据库安全的关键手段，它可以迅速恢复数据以应对病毒攻击、硬件故障和自然灾害等安全事件。

另外，定期的安全漏洞扫描和补丁更新也是保护ORACLE数据库安全的有效方法，以及
员工的安全培训和意识提升也是至关重要的。

综上所述，《ORACLE数据库安全解决方案》需要综合利用
加密技术、数据库审计和监控、访问控制、密码策略、多因素身份认证、备份和恢复、安全漏洞扫描等多种手段来保护企业的核心数据安全。

只有综合运用这些安全措施，才能确保ORACLE数据库的稳定和安全性，从而保护企业的核心资产和声誉。

谈关于Oracle数据库安全性管理摘要：数据库的安全问题直接关系到的信息数据高效，准确，完整传输的基础前提，Oracle数据库以其稳定性，优异的性能和高效率等特点被各大行业广泛使用。

但在实际应用过程中，存在很多安全隐患。

本文根据Oracle数据库的功能和实际使用情况，简要分析数据库安全技术，并提出数据库安全解决方案。

关键词：Oracle数据库；安全性；管理Abstract: Information database security issues directly related to the efficient, accurate, complete the basic premise of transmission, Oracle database with its stability, widely used features excellent performance and high efficiency are the major industry. But in practical application process, there are many security risks. In this paper, according to the Oracle database function and the actual use, the brief analysis of database security technology, and put forward the solution of security database.Key words: Oracle database; security; management数据库安全一直是数据库管理员关注的焦点，数据库的数据丢失和从未经授权被非法用户入侵已使得数据库管理员心力交瘁。

Oracle数据库在正常情况下能够保证数据的安全和系统的稳定，为用户提供正确的数据，但由于计算机系统存在的安全问题，或者由于数据库用户出现对系统的误操作，加之Oracle数据库自身存在的一些漏洞，都会影响到数据库中数据的正确性和安全性，造成数据库的破坏和其中数据的丢失，严重的甚至使整个系统陷入瘫痪状态。

ORACLE 12C 安全隐患系列（一）又喜又悲的新功能-INHERITPRIVILEGES从三月开始，安华金和安全实验室会陆续推出系列文章，专门以Oracle数据库为研究对象，展开安全隐患的分析研究，为大家带来安全防范建议，帮助大家做好数据库安全防护。

本期推出ORACLE12C 安全隐患系列（一），如果您或您的团队正在使用Oracle12C，或打算使用Oracle12C，请一定按照本文思路对用户的inherit privileges权限进行合理分配，杜绝安全隐患。

一. 摘要在12.1之后的Oracle版本中引入了一个和安全相关的权限—INHERIT PRIVILEGES。

这个权限可以赋予用户或角色。

喜的是，Oracle引入这个权限的目标是解决调用者权限可能造成的安全隐患。

然而悲的是，在12.1的默认配置下，INHERIT PRIVILEGES并不会起到提高安全性的作用。

只有用户重新配置INHERIT PRIVILEGES才能真正达到Oracle设计INHERIT PRIVILEGES提高安全性目的。

要弄清楚如何正确配置INHERIT PRIVILEGES，首先要搞清楚三个问题：1.调用者方式的安全隐患。

2.INHERIT PRIVILEGES是如何工作的？3.INHERIT PRIVILEGES应该如何配置？二. 调用者方式-存在安全隐患Oracle函数、存储过程的创建不同于其他数据库，可以采取两种截然不同的方式建立。

一种是定义者权限（D efiner’s right）,一种是调用者权限（I nvoker’s right）。

调用者权限创建的函数或存储过程，在创建过程中不会判断创建者是否拥有对存储过程或函数中调用的表、视图和对象的执行权限。

简单地说，就是调用者方式允许低权限用户在函数或存储过程中使用超越自身的权限。

允许超越自身权限带来了便利，也同时给数据库带来非法提权、非法操作、非法获取敏感信息等一系列安全隐患。

oracle12c oratop详解Oracle是一个大型的关系型数据库管理系统。

它具有高性能、安全、可靠等特点，并且被广泛应用于企业级应用程序和数据仓库等领域。

Oracle 12c是Oracle公司推出的最新一代数据库管理系统，它引入了许多新的功能和改进，提高了数据库的性能和可用性。

Oratop是一个用于监视和调优Oracle数据库的命令行实用程序。

它提供了许多工具和功能，帮助数据库管理员和开发人员监控和优化数据库的性能。

下面将详细介绍Oracle 12c和Oratop的一些重要功能和用途。

Oracle 12c的特点和改进：1.多租户架构：Oracle 12c引入了多租户架构，可以将一个物理数据库划分为多个逻辑数据库，每个逻辑数据库都可以独立管理和配置。

这种架构可以提高数据库的资源利用率，降低成本。

2.数据库内存虚拟化：Oracle 12c可以将数据库缓存的数据虚拟化到内存中，以加快数据访问的速度。

这种虚拟化技术可以提高数据库的性能，降低I/O开销。

3.多线程查询：Oracle 12c引入了并行查询功能，可以同时执行多个查询操作。

这种功能可以提高数据库的查询性能，加快数据检索的速度。

4.数据压缩：Oracle 12c提供了数据压缩功能，可以将数据库中的数据进行压缩存储，以减少存储空间的占用。

这种功能可以提高数据库的存储效率，降低存储成本。

5.自动化管理：Oracle 12c提供了自动化管理功能，可以自动进行数据库运维和监控。

这种功能可以减少管理员的工作量，提高数据库的可靠性和安全性。

Oratop的功能和用途：1.实时监控：Oratop可以实时监控数据库的各种系统指标，如CPU利用率、内存使用情况、I/O等。

这些指标可以帮助管理员及时发现和解决数据库性能问题。

2.会话跟踪：Oratop可以跟踪和监控数据库的会话，包括当前活动的会话、等待事件和SQL语句等。

这些信息可以帮助管理员分析数据库的性能瓶颈，优化SQL查询。