The Lifecycle, Architecture, and Legacy of Oracle Database 11g Release 2 for Microsoft Windows (32-Bit) Oracle Database 11g Release 2 (11.2.0.1 - 11.2.0.4) for Microsoft Windows (32-bit) stands as one of the most historically significant releases in the evolution of enterprise relational database management systems (RDBMS). Launched during an era when IT infrastructures were rapidly transitioning from 32-bit to 64-bit architectures, this specific package bridged the gap for thousands of organizations globally. It brought enterprise-grade data warehousing, clustering, and automation down to the standard x86 Windows platform. While technology has shifted dramatically toward 64-bit systems and cloud-native environments, understanding Oracle 11g R2 32-bit remains critical for database administrators (DBAs) managing legacy systems, executing migration projects, or maintaining industrial application stacks. Architectural Profile and Technical Specifications Oracle Database 11g Release 2 for 32-bit Windows was engineered specifically for the Intel x86 (IA-32) architecture. Operating within a 32-bit paradigm imposes strict physical limitations and unique memory management challenges that separate it from its 64-bit counterpart. The 4 GB Memory Barrier The defining characteristic of any 32-bit operating system is its maximum addressable memory space of 4 Gigabytes ( 2322 to the 32nd power Virtual Address Space (VAS): By default, Microsoft Windows splits this 4 GB space down the middle: 2 GB is reserved for the operating system kernel, and 2 GB is allocated to user-mode processes. The Oracle Process Model: On Windows, Oracle Database operates as a single monolithic process ( oracle.exe ). All database threads—including background processes like PMON, SMON, DBWn, LGWR, and every single user session—must fit inside this single user-mode Virtual Address Space. Overcoming Memory Constraints: /3GB and AWE To make Oracle 11g R2 viable for production workloads on 32-bit Windows, DBAs had to employ specific OS-level and database-level workarounds to prevent ORA-04030 (out of process memory) errors. The /3GB Switch (BCDEdit): By modifying the Windows boot configuration using the /3GB switch (or increaseuserva in newer Windows bootloaders), the OS kernel allocation was shrunk to 1 GB, expanding the oracle.exe user-mode process space to 3 GB. Address Windowing Extensions (AWE): To utilize physical RAM beyond 4 GB, Oracle 11g R2 utilized Windows AWE. By enabling USE_INDIRECT_DATA_BUFFERS = TRUE in the initialization parameter file ( init.ora ), Oracle could map the Database Buffer Cache into extended physical memory. However, critical memory pools like the Shared Pool and Large Pool still had to reside entirely within the primary 3 GB virtual address space. Key Features and Innovations in Release 2 Despite the hardware constraints of the 32-bit platform, Oracle packed Release 2 with revolutionary database features designed to lower total cost of ownership (TCO) and maximize performance. Automatic Storage Management (ASM) Cluster File System (ACFS): Release 2 introduced Grid Infrastructure, combining ASM and Oracle Clusterware. ACFS provided a multi-platform scalable file system to manage application files, removing the need for third-party cluster file systems on Windows. Edition-Based Redefinition (EBR): EBR allowed organizations to upgrade application database objects (like PL/SQL packages, views, and triggers) while the application was actively in use, achieving true 24/7 availability. Oracle Real Application Clusters (RAC): 11g R2 simplified Windows clustering. It introduced Single Client Access Name (SCAN), providing a single domain name for clients to connect to any node in the cluster, completely decoupling client configurations from cluster node changes. Hybrid Columnar Compression (HCC): While primarily optimized for Oracle Exadata storage, 11g R2 laid the groundwork for advanced compression capabilities, allowing historic enterprise data to be compressed up to 10x or more. Advanced Data Guard: It allowed physical standby databases to be opened read-only for reporting and backup offloading while simultaneously applying redo data from the primary database (Active Data Guard). Compatibility, Lifespan, and Support Status Oracle Database 11g Release 2 (32-bit) was officially supported on specific iterations of Windows built for x86 architectures. Supported Operating Systems Microsoft Windows XP Professional Microsoft Windows Server 2003 and 2003 R2 Microsoft Windows Server 2008 Microsoft Windows 7 (Professional, Enterprise, and Ultimate) Microsoft Windows 8 and Windows Server 2012 (introduced later in terminal patchsets like 11.2.0.4) Support Timeline Lifecycle Oracle 11g R2 followed Oracle’s traditional Lifetime Support Policy: Premier Support: Ended in January 2015. Extended Support: Ended in December 2020. Sustaining Support: Indefinite. Currently, Oracle 11g R2 is in Sustaining Support . This means that while existing users can still download existing patches, documentation, and open service requests, Oracle no longer provides new bug fixes, security alerts, or Critical Patch Updates (CPUs) for this version. Step-by-Step Installation Pre-requisites Deploying Oracle 11g R2 on a legacy 32-bit Windows system requires careful environmental preparation to avoid configuration failures during the Oracle Universal Installer (OUI) phase. 1. Hardware Requirements Physical Memory (RAM): Minimum 1 GB (2 GB or more highly recommended). Virtual Memory (Swap Space): Double the amount of physical RAM. Disk Space: At least 4.5 GB for the database software installation and an additional 2 GB for a seed database. 2. Windows Environment Configurations Administrative Privileges: The user account executing the installation must belong to the local Administrators group. Static IP / Loopback Adapter: If installing on a machine using DHCP (like a local development laptop), a Microsoft Loopback Adapter must be installed and configured with a static IP address to ensure stable Oracle Net listener binding. Windows Architecture Validation: Verify the operating system is strictly 32-bit by opening the command prompt and running systeminfo . The "System Type" must display X86-based PC . The Modern Context: Risks and Migration Strategies Running a production enterprise database on Oracle 11g R2 32-bit Windows carries significant operational liabilities. Modern organizations actively target these environments for immediate decommissioning or modernization. Primary Operational Risks Security Vulnerabilities: Lacking modern Critical Patch Updates (CPUs), these databases are highly vulnerable to unpatched security exploits, risking data breaches and compliance violations (e.g., PCI-DSS, HIPAA). Hardware Atrophy: Finding modern enterprise server hardware capable of natively running legacy 32-bit Windows operating systems is exceptionally difficult. Severe Performance Bottlenecks: The 4 GB addressable memory boundary completely cripples performance under modern, data-heavy multi-user workloads. Migration Paths to Modern Oracle Architecture To modernize, DBAs typically execute a phased upgrade path moving away from 32-bit architectures toward 64-bit cloud or on-premise environments (such as Oracle 19c or 23c). [Legacy State] [Intermediate Staging] [Target State] Oracle 11g R2 (32-bit Windows) --> Oracle 11g R2 (64-bit Linux/Win) --> Oracle 19c/23c (64-bit Cloud/On-Prem) Cross-Platform Migration via Data Pump: Because changing from a 32-bit platform to a 64-bit platform changes the binary format (endianness/word size), a direct in-place upgrade is impossible. DBAs use expdp (Data Pump Export) on the 32-bit system and impdp (Data Pump Import) on a newly provisioned 64-bit host. Transportable Tablespaces (TTS): For massive databases, TTS allows the moving of datafiles directly between 32-bit and 64-bit Windows environments, minimizing downtime by only exporting/importing metadata. Oracle GoldenGate : For zero-downtime migrations, GoldenGate captures real-time data changes from the transaction logs of the 32-bit 11g database and replicates them to a modern 64-bit Oracle destination database until the final cutover. If you are currently evaluating an Oracle 11g R2 32-bit Windows system, let me know: Is this system for a local development environment or a production legacy application ? I can provide tailored technical guidance or scripts based on your specific operational goals.
Comprehensive Guide to Oracle Database 11g Release 2 for Microsoft Windows (32-Bit) Oracle Database 11g Release 2 (11.2) represents a significant milestone in enterprise data management. While newer 64-bit architectures dominate modern deployments, the 32-bit version for Microsoft Windows remains a critical legacy platform for specific application stacks, testing environments, and specialized hardware configurations. This technical guide covers the architecture, installation prerequisites, memory constraints, and management strategies for running Oracle 11g R2 on a 32-bit Windows operating system. 1. Architectural Overview and Memory Constraints The defining characteristic of any 32-bit software environment is its strict memory limitation. Understanding how Oracle Database 11g R2 handles these constraints on Windows is essential for stable operations. The 4GB RAM Barrier A 32-bit architecture can inherently address a maximum of 4 Gigabytes (GB) of virtual memory address space. On Microsoft Windows, this space is divided by default: User Mode Space: 2 GB allocated for applications and processes (including the Oracle database instance). Kernel Mode Space: 2 GB reserved for the operating system operating requirements. Because Oracle Database on Windows runs as a single monolithic process ( oracle.exe ) utilizing multiple threads, the entire System Global Area (SGA), Program Global Area (PGA), and thread overhead must fit within this 2 GB user-mode memory limitation. Bypassing Limitations: /3GB and VLM To maximize database performance on 32-bit Windows, administrators often implement workarounds to reallocate memory: The /3GB Switch: By modifying the Windows boot configuration (via BCDEdit on modern legacy Windows versions), you can shift the boundary to allow 3 GB for user-mode applications and 1 GB for the kernel. This grants oracle.exe up to 3 GB of addressable space. Very Large Memory (VLM) / AWE: Intel’s Address Windowing Extensions (AWE) allow 32-bit systems to access physical memory beyond 4 GB. By enabling the USE_INDIRECT_DATA_BUFFERS initialization parameter in Oracle, the database can use extended memory for the database buffer cache, pushing the system past standard limits. 2. Key Features of Oracle 11g Release 2 Despite structural memory limitations on 32-bit systems, Oracle 11g R2 delivers robust enterprise capabilities: Automatic Storage Management (ASM): Simplifies database storage management by consolidating tools into a single interface, offering automated file striping and mirroring. Real Application Clusters (RAC): Provides high availability and scalability by allowing multiple instances to access a single database across a Windows Server cluster. Oracle Data Guard: Offers comprehensive disaster recovery and data protection strategies through physical and logical standby databases. Advanced Compression: Reduces storage footprints by compressing transactional data, historical records, and backups while improving query performance through reduced I/O. Total Recall (Flashback Data Archive): Allows administrators to query historical data as it existed at any point in time, fulfilling regulatory and compliance auditing needs seamlessly. 3. System Requirements and Prerequisites Before deploying Oracle 11g R2 (32-bit) on a Windows environment, ensure the host system fulfills the minimum hardware and software standards. Hardware Minimums Processor: Intel Pentium 4, Xeon, or AMD Athlon/Opteron (32-bit or 64-bit processors capable of running 32-bit OS). RAM: Minimum 1 GB (2 GB or more highly recommended). Virtual Memory (Swap Space): Double the amount of physical RAM. Disk Space: Minimum 4.5 GB for the database software installation and an additional 2 GB for seed database creation. Supported Windows Operating Systems (32-Bit) Windows 7 (Professional, Enterprise, and Ultimate editions) Windows Server 2008 (Standard, Enterprise, and Datacenter editions) Windows Server 2008 R2 (Note: Server 2008 R2 is natively 64-bit, but can run 32-bit Oracle client software; the 32-bit database server runs on standard 2008 32-bit editions). 4. Step-by-Step Installation Guide Follow these steps to complete a standard installation using the Oracle Universal Installer (OUI). Step 1: Download and Extract Download the Oracle Database 11g Release 2 software media for Windows (32-bit). The installation files are typically split into two ZIP archives. Extract both archives into the exact same parent directory to ensure the installer can locate all necessary components automatically. Step 2: Launch the Installer Navigate to the extracted directory, right-click on setup.exe , and select Run as Administrator . This bypasses Windows User Account Control (UAC) restrictions during configuration. Step 3: Configure Security Updates Provide your My Oracle Support credentials to receive proactive security alerts, or uncheck the box to bypass this step for isolated lab environments. Step 4: System Selection Select Create and Configure a Database to install the database software and build a seed database instance simultaneously. If you only require the engine binaries, choose Install Database Software Only . Step 5: System Class Choose Desktop Class if installing on a workstation for development or testing. Choose Server Class if deploying on a dedicated Windows Server to unlock advanced deployment configurations like RAC or ASM. Step 6: Typical Installation Configuration Define the following baseline paths and settings: Oracle Base: The root directory for all Oracle software products (e.g., C:\app\Administrator ). Software Location (Oracle Home): The specific directory for the 11g R2 binaries. Database File Location: Storage path for datafiles, control files, and redo logs. Global Database Name: The unique identifier for your database instance (e.g., orcl.localdomain ). Administrative Password: Define a secure password that will apply uniformly to the system accounts ( SYS , SYSTEM , SYSMAN , DBSNMP ). Step 7: Prerequisites Check and Execution The OUI will run an automated script checking for architecture compatibility, physical memory minimums, and network settings. Once passed, review the summary page and click Install . The Database Configuration Assistant (DBCA) will launch automatically at the end of the process to build the physical database structures. 5. Post-Installation Best Practices To guarantee the stability and security of your newly deployed 32-bit database instance, implement these post-installation actions immediately: Manage Windows Services Oracle runs as background services on Windows. Ensure that the core services are configured correctly via the Windows Services panel ( services.msc ): OracleServiceSID (where SID is your database name) must be set to Automatic . OracleOraDb11g_home1TNSListener must be set to Automatic to manage inbound application connection requests. Optimize Memory Parameters Because of the 32-bit constraints, keep your MEMORY_TARGET or SGA_TARGET initialized parameters conservative. For a standard 2 GB user-mode limit, keep your total instance target below 1.2 GB to prevent the oracle.exe process from crashing due to unexpected thread-allocation memory exhaustion. Apply Critical Patch Updates (CPUs) Ensure you apply the final available updates and security patches released for the 11g R2 lifecycle. Secure the system by locking default accounts that are not actively in use and changing temporary administrative passwords. 6. Lifecycle and Migration Pathways Oracle Database 11g Release 2 has long passed its final dates for Premier and Extended Support windows. Running production workloads on a 32-bit version of this platform introduces operational risks, including lack of security updates and modern OS incompatibility. Organizations still utilizing this specific software configuration should consider the following migration pathways: Cross-Platform Migration: Migrate the database from 32-bit Windows to 64-bit Windows or 64-bit Oracle Linux using Oracle Data Pump ( expdp / impdp ) or Transportable Tablespaces. Database Upgrade: Upgrade the legacy database to actively supported long-term support releases like Oracle 19c or Oracle 23ai to guarantee security patch compliance and exploit modern cloud automation capabilities. To help narrow down your migration options, could you tell me what type of applications rely on this database and whether you plan to keep the environment on-premise or move it to the cloud ? Share public link This public link is valid for 7 days and shares a thread, including any personal information you added. This link or copies made by others cannot be deleted. If you share with third parties, their policies apply. Can’t copy the link right now. Try again later.
Comprehensive Guide to Oracle Database 11g Release 2 for Microsoft Windows (32-Bit) Oracle Database 11g Release 2 (11.2) represents a major milestone in database technology, offering robust data management, automation, and performance optimizations. While modern enterprise environments have largely transitioned to 64-bit architectures, the 32-bit version for Microsoft Windows remains a critical component for legacy application support, specialized development environments, and specific testing scenarios. This article explores the core features, architectural constraints, installation prerequisites, and deployment strategies for Oracle Database 11g Release 2 on Windows 32-bit platforms. Architectural Considerations and Limitations Deploying a relational database management system (RDBMS) on a 32-bit architecture introduces strict physical limitations. Understanding these constraints is vital for maintaining system stability and performance. Memory Restrictions: The most critical limitation of a 32-bit Windows environment is the 4 GB virtual address space. By default, the Windows kernel reserves 2 GB for system processes, leaving only 2 GB for user-mode processes, including the Oracle database instance. The 3GB Switch (/3GB): System administrators can alter the boot configuration using the /3GB switch in older Windows Server versions or the increaseuserva command in newer deployments. This reallocates the boundary to give 3 GB of address space to user applications and 1 GB to the kernel. SGA and PGA Tuning: Because the Entire Oracle instance—including the System Global Area (SGA) and Program Global Area (PGA)—must fit within this user-mode memory space, database administrators (DBAs) must carefully size memory pools. An oversized SGA will prevent the Oracle executable ( oracle.exe ) from starting due to insufficient contiguous memory. VLM (Very Large Memory): Oracle provides Address Windowing Extensions (AWE) to utilize physical memory beyond 4 GB. However, this adds architectural complexity and can introduce performance overhead. Key Features of Oracle 11g Release 2 Despite the underlying 32-bit constraints, Release 2 brings a powerful suite of features designed to maximize efficiency, availability, and ease of management. 1. Automatic Storage Management (ASM) and Grid Infrastructure Oracle 11gR2 integrated ASM with Oracle Clusterware into a single unified platform known as Grid Infrastructure. ASM simplifies disk management by consolidating physical disks into logical disk groups, automatically balancing data loads across available storage to eliminate hot spots. 2. Real Application Clusters (RAC) Oracle RAC allows multiple instances on different servers to access the same physical database simultaneously. On Windows 32-bit, RAC can be used to achieve high availability and fault tolerance, ensuring that the failure of a single node does not result in database downtime. 3. Oracle Recovery Manager (RMAN) Enhancements RMAN in 11gR2 includes advanced compression techniques, duplicate database optimizations, and the ability to perform cross-platform backups. These features reduce the storage footprint of backups and streamline disaster recovery workflows. 4. Data Guard and Active Data Guard Data Guard ensures high availability by maintaining one or more standby databases as exact copies of the production database. Active Data Guard allows read-only access to a physical standby database, enabling reporting tools and backup processes to be offloaded from the primary system. 5. Compression and Performance Tuning Advanced Compression features allow organizations to compress data across all types of workloads—including OLTP, data warehousing, and unstructured data (LOBs)—reducing storage costs and improving I/O performance by keeping more data blocks in the buffer cache. System Requirements and Prerequisites Before initiating the installation process, ensure your environment meets the minimum hardware and software requirements. Hardware Requirements Processor: Intel Pentium 4, Intel Xeon, AMD Opteron, or Athlon (32-bit architecture). RAM: Minimum 1 GB (2 GB or more strongly recommended). Virtual Memory (Swap Space): Double the amount of physical RAM. Disk Space: Approximately 4.5 GB to 5.5 GB for the software installation, plus additional space for database files. Supported Windows Operating Systems (32-Bit) Windows 7 (Professional, Enterprise, Ultimate) Windows Server 2008 (Standard, Enterprise, Datacenter) Windows Server 2008 R2 (Note: Server 2008 R2 is natively 64-bit; check compatibility matrices for specific 32-bit client/software configurations) Windows XP Professional (Supported on earlier patch sets of 11gR2; consult Oracle Support Certification Matrix for exact versions) Step-by-Step Installation Workflow Oracle Database 11g Release 2 utilizes the Oracle Universal Installer (OUI), a graphical tool that guides you through the configuration process. Step 1: Download and Extract Software Download the installation zip files (typically split into File 1 and File 2) from the official Oracle distribution portal. Extract both zip archives into the same destination directory to ensure the installer can locate all necessary components. Step 2: Run the Installer Navigate to the extracted directory, right-click on setup.exe , and select Run as Administrator . This grants the installer the administrative privileges required to modify the Windows Registry and create system services. Step 3: Configure Security Updates The initial screen prompts you for an email address to receive security updates via My Oracle Support. You can opt out of this by unchecking the box if the system resides in an isolated environment. Step 4: Select Installation Options Installation Option: Choose "Create and configure a database" to install the database software and build a functional seed database simultaneously. System Class: Select "Desktop Class" if installing on a laptop or workstation for development, or "Server Class" if deploying on a dedicated server infrastructure. Step 5: Specify Typical Configuration Settings Define the primary installation paths: Oracle Base: The top-level directory for Oracle software and configuration files (e.g., C:\app\Oracle ). Software Location (Oracle Home): The specific directory where the RDBMS binaries reside. Database File Location: Storage path for datafiles, control files, and redo logs. Global Database Name & SID: Define the unique identifier for your database instance (e.g., orcl ). Administrative Passwords: Set a secure, uniform password for the system administrative accounts ( SYS , SYSTEM , SYSMAN , DBSNMP ). Step 6: Prerequisite Checks and Summary The installer executes a series of background verification checks to confirm sufficient memory, architecture compliance, and disk space. Address any warnings, review the configuration summary screen, and click Install . Step 7: Database Configuration Assistant (DBCA) Once the software installation reaches 100%, the OUI automatically launches the DBCA to create the physical database structures. Upon completion, a confirmation dialog displays critical connection URLs, including the Oracle Enterprise Manager (EM) Database Control link. Post-Installation Best Practices To guarantee operational efficiency and data security, complete the following post-installation procedures: Configure Windows Services: Ensure the critical Windows services—specifically OracleServiceSID and OracleOraDb11g_home1TNSListener —are set to start automatically upon system boot. Apply Latest Patch Sets: 32-bit environments face unique stability challenges. Regularly apply the latest Program Updates, Critical Patch Updates (CPUs), and Patch Set Updates (PSUs) via My Oracle Support to guard against known security vulnerabilities and memory leaks. Optimize Network Connections: Configure the listener.ora and tnsnames.ora configuration files located in the %ORACLE_HOME%\network\admin directory to govern client-server network communications. Implement an RMAN Backup Strategy: Establish automated, routine automated backup schedules using RMAN to protect against hardware failure, file corruption, or user error. Conclusion Oracle Database 11g Release 2 for Microsoft Windows (32-bit) remains a dependable, robust engine for handling business-critical operations within its architectural limits. By carefully managing memory allocations, maintaining strict adherence to OS prerequisites, and executing systematic maintenance routines, database administrators can maximize the performance, lifecycle, and reliability of their legacy enterprise data infrastructure. If you are planning a deployment, let me know how you intend to use this system: Are you setting up a fresh installation or doing a migration ? Which specific Windows OS version are you targeting? What is the primary workload type (e.g., OLTP, Data Warehousing, or Local Development)? I can provide specialized advice on memory parameters or specific configuration steps tailored to your environment. Share public link This public link is valid for 7 days and shares a thread, including any personal information you added. This link or copies made by others cannot be deleted. If you share with third parties, their policies apply. Can’t copy the link right now. Try again later.
user wants a long article about Oracle Database 11g Release 2 for Microsoft Windows (32-bit). This is a legacy product. I need to search for information about system requirements, features, download options, installation, end-of-life status, potential use cases, and any modern equivalents or alternatives. I'll follow the search plan as provided. search results are in. I'll now open the most relevant pages to gather details. have gathered information from various sources. Now I need to write a comprehensive article. The article will cover an introduction, system requirements, installation, features, support lifecycle, use cases, and migration paths. I'll structure it with these sections and cite the relevant sources. Now I'll write the article. Database 11g Release 2 (11.2) for Microsoft Windows (32-bit) is a legacy release that provided enterprise data management capabilities on x86 hardware. While its support lifecycle has ended, it remains historically important. This article provides a comprehensive reference covering system requirements, supported operating systems, installation procedures, key features, end-of-life status, and modern migration paths. oracle database 11g release 2 for microsoft windows -32-bit-
System Requirements and Supported Operating Systems Before installing Oracle Database 11g R2 for 32-bit Windows, checking hardware and software compatibility is necessary for a successful deployment. Hardware Requirements Oracle defines specific hardware requirements that should be met:
System Architecture : Intel (x86), AMD64, or Intel EM64T processor Physical Memory (RAM) : 1 GB minimum; on Windows 7, Windows 8, or Windows 8.1, 2 GB or more is recommended Virtual Memory : When physical memory is between 2 GB and 16 GB, virtual memory should be set to 1× RAM size; if physical memory exceeds 16 GB, set virtual memory to 16 GB Disk Space : A total of approximately 5.35 GB is required (standard installation type) or 4.89 GB (extended installation type) Video Adapter : 256 colors minimum Screen Resolution : 1024 × 768 or higher
For the starter database specifically, an additional 1.55 GB of disk space is needed. Oracle strongly recommends installing the Oracle database home (binaries, trace files, etc.) on NTFS or Oracle ACFS, and placing database files on Oracle ASM or NTFS—using FAT32 is not recommended for security reasons. Supported Microsoft Windows Operating Systems The 32-bit version of Oracle Database 11g Release 2 is supported on the following Microsoft Windows operating systems: The Lifecycle, Architecture, and Legacy of Oracle Database
Windows XP Professional Windows Server 2003 (all editions) Windows Server 2003 R2 (all editions) Windows Vista (Business, Enterprise, and Ultimate editions) Windows Server 2008 (all editions) Windows 7
Support for Windows 8 and Windows 8.1 was added in later patchset updates (11.2.0.4). Note that Oracle RAC is not supported for 32-bit Windows in 11gR2 and later releases.
Installation Guide Downloading the Installation Files To install Oracle Database 11g Release 2 on 32-bit Windows, download the two required ZIP files. For version 11.2.0.1.0, the following links were historically available from Oracle: The 4 GB Memory Barrier The defining characteristic
Disk 1 : win32_11gR2_database_1of2.zip (approximately 1.6 GB) Disk 2 : win32_11gR2_database_2of2.zip (approximately 632 MB)
Both files must be downloaded and extracted into the same directory— stage is created from the second file, and without it the installation may not succeed. Installation Steps