GemStone/S is a high-performance Object database management system (OODBMS), which is used to support large-scale, highly concurrent Transaction processing processing and application development. It provides a complete object-oriented development environment, including object-oriented database, application development tools and distributed Transaction processing mechanism. The founding of GemStone/S can be traced back to the 1970s, initially developed by Doug Engelbart et al. of Xerox PARC (Parker Research Center), and later further promoted and developed by GemStone Systems. Currently, GemStone/S is held by VMware. GemStone/S is applicable to Transaction processing systems that require high performance and concurrency, especially in scenarios where a large number of concurrent transactions need to be processed or rapid response time is required. It is suitable for various industries, such as finance, telecommunications, e-commerce, and supply chain management. The advantages of GemStone/S include: 1. High performance: GemStone/S uses the In-memory database and object-oriented data storage model to store and process data in memory, so as to quickly respond to transaction requests. 2. High concurrency: GemStone/S supports multi-user concurrent access and Transaction processing, and can handle a large number of concurrent requests. 3. High scalability: GemStone/S can be extended through a distributed architecture, supporting horizontal and vertical scaling to meet the needs of different scales and loads. 4. Transaction consistency: GemStone/S uses MVCC (Multiversion concurrency control) to achieve transaction consistency and ensure transaction isolation and Concurrency control. 5. Hot backup and recovery: GemStone/S supports hot backup and recovery functions to ensure data persistence and reliability. The drawbacks of GemStone/S include: 1. Learning curve: GemStone/S uses object-oriented data model and programming language, which may require some time and knowledge to learn and adapt. 2. High cost: GemStone/S is a commercial product that may require some investment to use and purchase. The technical principle of GemStone/S is based on the object-oriented data model and persistent In-memory database. It uses an object-oriented programming language similar to Smalltalk, organizes data into objects, and uses concepts such as inheritance, encapsulation, and polymorphism between objects to provide data abstraction and encapsulation. The performance analysis of GemStone/S shows that it has high throughput and low latency, can support millions of concurrent transactions, and achieve data distribution and load balancing among multiple nodes. The official website of GemStone/S is https://www.gemtalksystems.com/gsdb.html Users can obtain more detailed information, documentation, and support about GemStone/S on the official website. To sum up, GemStone/S is an object-oriented high-performance Database management system, which is suitable for large-scale, highly concurrent Transaction processing processing and application development. It has the advantages of high performance, high concurrency, high scalability and transaction consistency, but requires investment in learning and purchase costs. Its technical principle is based on the object-oriented data model and persistent In-memory database, and can be horizontally and vertically extended through the distributed architecture.

ObjectDB is an object centered Database management system (ODBMS), which provides a way to store objects persistently. Objects can be directly stored in the database without transforming them into a Relational model. The following is a detailed introduction to Object DB: Database Introduction: ObjectDB is a high-performance Java Object database, which can store and retrieve objects in Java applications. It supports JPA (Java Persistence API) and JDO (Java Data Object) standards and can seamlessly integrate with existing Java applications. ObjectDB is written in pure Java and is an embedded database that can run directly on the Java virtual machine (JVM). Date of establishment, founder or company: Object DB was founded by Object DB Software Co., Ltd. in 2006. It is an Israeli software company founded by Ireneusz L. Klepaczewski. Applicable scenario: Object DB is suitable for Java applications that require high-performance and real-time data access. It can be used for web applications, distributed systems, financial applications, scientific applications, database driven enterprise applications, and more. Advantages: 1. High performance: Object DB uses memory management and high-speed I/O technology to provide fast data access and processing. It supports indexing and query optimization, providing excellent performance in large amounts of data. 2. Object oriented: The ObjectDB database stores Java objects directly, without the need to convert them to a Relational model. This allows developers to process data more naturally and make it easier to associate objects. 3. Transaction Support: Object DB provides ACID (Atomicity, Consistency, Isolation, and Persistence) transaction support to ensure data consistency and reliability. 4. JPA and JDO standard support: ObjectDB fully supports JPA and JDO standards and can be seamlessly integrated with other ORM (Object–relational mapping) frameworks. 5. Embedded database: Object DB is an embedded database that can be directly used in Java applications without the need for additional installation and configuration. Disadvantages: 1. Single language support: Object DB mainly supports the Java language, with relatively limited support for other programming languages. 2. Community support: Compared to some mainstream relational databases, the user community of Object DB is relatively small, so there are relatively few solutions and support that may be found when encountering problems. Technical principles: The technical principles of Object DB mainly include object model, persistence, query optimization, and indexing. It uses an object model to directly store and manage Java objects, and converts them into persistent states through persistence technology to ensure data persistence. Object DB also implements query parsing and optimization to improve query performance, and provides various indexing mechanisms such as B-Tree index and hash index. Performance analysis: Object DB is designed as a high-performance database system with the following performance characteristics: 1. Fast read and write: Object DB uses high-speed I/O technology and memory management to achieve fast data read and write operations. 2. Efficient indexing: Object DB supports multiple indexing mechanisms, such as B-Tree indexing, hash indexing, etc., which can provide fast index access in large amounts of data. 3. Query optimization: Object DB implements query parsing and optimization techniques, which can optimize query execution plans and improve query performance. Official website: The official website of Object DB is https://www.objectdb.com/ You can obtain more information, documentation, demonstrations, and downloads about Object DB on this website. Summary: ObjectDB is a high-performance Java Object database, which is object centric and provides the ability to directly persist and retrieve Java objects. Object DB supports JPA and JDO standards and can seamlessly integrate with existing Java applications. It has the advantages of high performance, object oriented, and transaction support, making it suitable for Java applications that require high-performance and real-time data access. However, Object DB mainly supports the Java language and has a relatively small user community. In general, ObjectDB is a powerful Object database solution that can provide efficient and convenient data persistence and access.

Versant Object Database is an object-oriented Database management system (DBMS), which takes objects as the basic unit of data storage and access. Here is a detailed introduction to the Versant Object Database: Database Introduction: Versant Object Database is a high-performance and highly scalable Object database. It is object centric, allowing developers to directly store complex data structures and relationships between objects in a database without the need for transformation or mapping. Versant Object Database helps developers accelerate application development speed and performance by providing efficient data persistence and query capabilities. Founding time and founder or company: Versant Object Database was created by Versant Corporation in 1988. Versant Corporation is a software company headquartered in Illinois, USA, specializing in object-oriented database and data management solutions. Applicable scenario: Versant Object Database is suitable for scenarios where complex objects and their relationships need to be stored and managed. It is particularly suitable for applications requiring high performance, high concurrency and scalability, such as real-time analysis, Big data processing, financial transactions, online games and other fields. In addition, Versant Object Database can be integrated with relational databases to meet the needs of enterprise level applications. Advantages: 1. Object oriented: Versant Object Database stores data as objects, which can be directly mapped to the object model of the application, simplifying the development process. 2. High performance: Versant Object Database has excellent read and write performance and can meet high concurrency access requirements through horizontal and vertical scaling. 3. High scalability: Versant Object Database can seamlessly scale to multiple nodes to support massive data storage and processing. 4. Data consistency: Versant Object Database ensures data consistency and integrity by supporting transaction and lock mechanisms. 5. Support for complex queries: Versant Object Database provides flexible and efficient query functions, supporting complex relationships and object navigation. Disadvantages: 1. The Learning curve is steep: Since Versant Object Database is an object-oriented database, it may take more time and resources to learn and master its usage compared with traditional relational databases. 2. Relatively small user group: Compared to mainstream relational databases, Versant Object Database has a smaller user group, resulting in relatively fewer related resources and communities. Technical principles: Versant Object Database uses a storage method similar to the distributed Hash table based on Object Management Technology (OMT). It supports object-oriented Data modeling and access, and provides high-performance query and transaction management mechanism. Performance analysis: Versant Object Database has significant performance advantages in object-oriented data storage and access. It supports large-scale concurrent access and has low read and write latency. In addition, the scalability of Versant Object Database enables it to handle large-scale datasets. Official website: Official website: https://www.actian.com/datacore/object-database-vodbc/?_gl=1 *1bdea8e*_ Gcl_ Aw * R0NMLjE2Mjc3Mzc1ODguQ2owS0NRanc0WUFBd0VLd01Sa2JMdDNORmc0Q2RaUzBhLWRUSjVubEtINU1Zc1VEZzN4Yi1uZU16UlpxR1czQmdWbkNRUFMd193Y0I2RUFBWWhPazhVN192cEVmd0FZnZCVWx1N2lNeUxRS1FnNuhSdllfbTllREJsVDlfbG1iN182ZnRRWk V5Y2JTMWxLdkEyN3pVcFBENGpEcldidDBRSWQ3aEJ5US0tRktNU05 TRENpTmIweHdIUDJSTDEzdz09-80290966d0ba4c7cf0610a3b2fa29c711ddc9a*_ Gcl_ DC * R0NMLjE2Mjc3Mzc1ODguQ2owS0NRanc0WUFBd0VLd01Sa2JMdDNORmc0Q2RaUzBhLWRUSjVubEtINU1Zc1VEZzN4Yi1uZU16UlpxR1czQmdWbkNRUFMd193Y0I2RUFBWWhPazhVN192cEVmd0FZnZCVWx1N2lNeUxRS1FnNuhSdllfbTllREJsVDlfbG1iN182ZnRRWk V5Y2JTMWxLdkEyN3pVcFBENGpEcldidDBRSWQ3aEJ5US0tRktNU05 TRENpTmIweHdIUDJSTDEzdz09--80290966d0ba4c7cf0610a3b2fa29c711ddc9a # VRTUe4KodebYnB8dvf22dFvRsmo4APFkkcKEO1EYvVo Summary: Versant Object Database is a high-performance and highly scalable Object database, which is suitable for scenarios where complex objects and their relationships need to be stored and processed. It has an object-oriented data model that provides high-performance query and transaction management mechanisms. However, compared with traditional relational databases, Versant Object Database has a steep Learning curve and a relatively small user group. Nevertheless, it is still an effective choice for developing high-performance, high concurrency, and scalable applications.

Db4o is a simple and easy to use object-oriented Database management system (ODBMS) for storing and querying objects. Its full name is "database for objects" (Object database), which can directly save object-oriented data to the database without mapping Relational model. Founded in 2000, it was co founded by Gunter Ramin and Christof Wittig. Db4o was originally developed by a German company called Speedo Software and was acquired by a company called Versant Corporation in 2007. Db4o is suitable for application scenarios that require simplicity, lightweight, and high performance, such as embedded devices, desktop applications, and mobile applications. It provides a convenient way to achieve transparent persistence of objects, while also possessing high performance and low memory usage. Compared to traditional relational databases, it provides faster access speed and better availability. The advantages of db4o include: 1. Lightweight: As an embedded database, db4o does not require complex installation and configuration processes and can be easily integrated into applications. 2. Fast: db4o adopts in memory indexing and caching technology to provide fast read and query performance. 3. Transparent persistence: db4o can directly store and retrieve objects without the need for data mapping and transformation. 4. Easy to use: db4o provides a simple API and Query language, enabling developers to easily operate the database. However, db4o also has some drawbacks: 1. Lack of maturity: Compared to traditional relational databases, the popularity of db4o in the market is relatively low, and the community support and tool ecosystem are relatively weak. 2. Does not support complex queries: The query function of db4o is relatively simple and does not support some complex relational database query operations. 3. Limited scalability: db4o may have performance problems when dealing with Big data volume and high concurrent access, which is not suitable for some application scenarios requiring high scalability. Technically, db4o is based on the principle of Object database. It uses B+tree indexing and caching technology to accelerate data reading and querying. It also supports functions such as Transaction processing processing and data replication to improve the reliability and availability of the database. Regarding performance analysis, db4o performs well in most read and write operations. It accelerates read operations by using memory indexing and caching, and for small-scale data volumes, read and write operations are very fast. However, when the amount of data increases, the performance of db4o will be affected to some extent, as it is not suitable for large-scale data processing and high concurrency access. Official website: http://www.db4o.com/ In summary, db4o is a simple, easy-to-use, high-performance Object database, suitable for embedded devices, desktop applications, mobile applications and other scenarios. It provides the advantages of transparent persistence, fast access speed, and low memory usage, but there are some limitations in terms of market maturity, complex queries, and scalability.

Perst is a high-performance embedded Object database, which is suitable for storing and managing objects in embedded devices, mobile devices and distributed environments. Perst provides high-speed and flexible data access and persistent storage by directly embedding databases into applications. The Pert database was developed by McObject and first released in 2002. McObject is a software company focused on embedded database technology, headquartered in Washington State, USA. The Pert database is suitable for various scenarios, especially in embedded and mobile devices, which typically have limited resources and processing power. Pert, with its lightweight and high-performance characteristics, can meet the database requirements of these devices. In addition, Perl also supports an object-oriented programming model and provides transaction support, indexing, querying, and processing of complex object relationships. The advantages of Perst include: 1. High performance: Perl adopts a series of optimization strategies to improve performance, including lockless concurrent access, cache management, and delayed writes. 2. Embedded: Perl can be directly embedded into applications without an independent database server, reducing resource consumption and complexity. 3. Flexible data model: Perl supports object-oriented data models, which can easily handle complex object relationships. 4. Cross platform support: Perl can be used on multiple platforms and operating systems, including Windows, Linux, Android, and more. However, Perst also has some drawbacks: 1. Lack of support for SQL: Compared with traditional relational databases, Perl does not support SQL Query language and needs to use object-oriented query interfaces for data query. 2. The Learning curve is steep: because Perst is a new database technology, developers may need some time to become familiar with its features and usage. The technical principle of Perst is based on a hybrid index structure of B-Tree and hash index. It uses cache management to improve access speed, and uses a random I/O access model to reduce File system fragmentation. In terms of performance, Perl has lower memory consumption and high-speed data access capabilities. It supports lockless concurrent access and can achieve high concurrency data operations. In addition, Perl also supports features such as incremental backup and data compression to improve the efficiency of data management. The official website of Perst is: https://www.mcobject.com/perst To sum up, Perst is a high-performance embedded Object database for embedded devices and mobile devices. It provides fast and flexible data access and persistent storage by directly embedding applications. Perst has the advantages of high performance, embedded features, flexible data model and cross platform support, but it lacks SQL support and may have a steep Learning curve. Its technical principles are based on B-Tree and hash indexing, using cache management and random I/O access models to improve performance. The official website of Perst is https://www.mcobject.com/perst .

VelocityDB is a high-performance Object database management system (ODBMS) with strong persistence, flexible data model and extensible architecture. It was developed by VelocityDB, a company headquartered in the United States. VelocityDB was initially released in 2004, when it was created and maintained by Johan Larsson. Since then, VelocityDB has continuously developed and improved, becoming a mature and stable database system. VelocityDB is suitable for many scenarios, especially for applications that require high performance and stability. For example, transaction processing in the financial field, large-scale data analysis in scientific research, and data storage and analysis in the Internet of Things (IoT) field. The advantages of VelocityDB include: 1. High performance: VelocityDB has excellent read and write performance, capable of handling high concurrency access and large-scale datasets. 2. Flexible data model: VelocityDB supports complex object relationships and can easily store and query any object and its associations. 3. Scalable architecture: VelocityDB can run in a distributed environment and improve performance and capacity by adding more nodes. 4. ACID feature: VelocityDB ensures the atomicity, consistency, isolation, and persistence of data. 5. Support for multiple programming languages: VelocityDB provides support for multiple programming languages, including C #, Java, Python, and more. The drawbacks of VelocityDB may include: 1. The Learning curve is steep: because VelocityDB has a complex data model and Query language, it may take some time and effort to learn and use it. 2. Limited vendor support: Compared to some mainstream databases, VelocityDB's vendor support may be limited, and users may need to rely on the community or solve problems themselves. The technical principle of VelocityDB is mainly based on the concept of Object database, which stores data as objects and uses B-tree indexes for efficient data access. VelocityDB also utilizes compression algorithms and caching mechanisms to improve read and write performance. It supports cross node data replication and distributed queries, and has good scalability. Regarding performance analysis, VelocityDB performs well in large-scale datasets and high concurrency access scenarios. It can handle millions or even billions of objects and provide fast read and write speeds. Meanwhile, VelocityDB's storage engine and query optimizer can effectively manage indexes and query plans, providing efficient data access. VelocityDB's official website: https://www.velocitydb.com/ Conclusion: VelocityDB is a high-performance, flexible and scalable Object database management system. It is suitable for applications that need to handle large-scale data and high concurrency access, and has rich functionality and optimized performance. Despite the steep Learning curve and limited vendor support, VelocityDB is still a powerful database system that can meet the needs of many complex applications.

ObjectivityDB is an object-oriented Database management system (DBMS), which provides highly scalable, distributed data storage and processing solutions for applications. ObjectivityDB was founded by Objectivity Inc. in 1988. This US based company mainly focuses on providing high-performance and reliable data management solutions. ObjectivityDB was originally designed for highly distributed and real-time applications, such as network management, intelligence analysis and applications in the Internet of Things. ObjectivityDB is suitable for scenarios that require processing large amounts of dynamic and complex data. It has high scalability and can handle massive amounts of data and high concurrency access. It also supports complex queries and analysis of multilingual and geographically distributed data. The advantages of ObjectivityDB include: 1. Object oriented data model: ObjectivityDB uses an object oriented data model, allowing developers to directly store and process data in an object-oriented manner, which is more in line with real-world models. 2. Highly scalable: The architecture of ObjectivityDB supports horizontal and vertical scaling, making it easy to handle large capacity and high traffic data. 3. Distributed architecture: ObjectivityDB supports the distribution of data between multiple nodes, providing fault tolerance and high availability. 4. High performance: ObjectivityDB adopts various optimization techniques, such as parallel processing and index optimization, to provide fast data access and queries. 5. Multi language support: ObjectivityDB supports multiple programming languages, such as Java, C++, and Python, making it easy for developers to develop in familiar languages. The drawbacks of ObjectivityDB include: 1. The Learning curve is steep: The use of ObjectivityDB needs to master the object-oriented data model and specific Query language. For developers without relevant experience, it is difficult to learn and use. 2. Complex deployment and maintenance: Due to the distributed architecture of ObjectivityDB, deployment and maintenance require a certain level of professional knowledge and experience. 3. High cost: Compared to some open source databases, ObjectivityDB has a higher license fee and may not be suitable for all projects. The technical principles of ObjectivityDB mainly include Object storage, Transaction processing and query optimization. It uses an object-oriented data storage model to achieve direct association and inheritance between objects by directly storing them in a database. In Transaction processing, ObjectivityDB supports ACID (atomicity, consistency, isolation and persistence) transactions to ensure data integrity and consistency. In terms of query optimization, ObjectivityDB uses various indexing techniques and query optimization strategies to improve query performance. In terms of performance analysis, ObjectivityDB has shown good performance in large-scale data storage and high concurrency access. Its architecture supports data sharding and distributed queries, which can be horizontally scaled by adding more computing and storage nodes. In addition, ObjectivityDB provides monitoring and diagnostic tools to help developers analyze and optimize database performance. The official website of ObjectivityDB is https://www.objectivity.com/ You can obtain more detailed information and documentation about ObjectivityDB on this website. To sum up, ObjectivityDB is an object-oriented high-performance and scalable Database management system, which is suitable for processing large-scale and complex data scenarios. Its technical principle and query optimization strategy can provide fast data access and query, but the Learning curve is steep, deployment and maintenance are complex, and there will be some costs.

EXtremeDB is a high-performance In-memory database system designed to provide fast and reliable data management solutions for real-time systems. It was developed by American company McObject and released in 2001. EXtremeDB is suitable for various embedded and real-time systems, including financial transactions, telecommunications systems, network devices, industrial control, and the Internet of Things. It can also be used as an independent database server, supporting SQL Query language and standard ODBC/JDBC interface. The main advantages of eXtremeDB include: 1. High performance: eXtremeDB is designed to handle massive real-time data, storing data in memory and achieving very low read and write latency. It also provides optimization techniques such as multithreading and fast indexing to further improve performance. 2. Reliability: eXtremeDB has transaction support and ACID features, ensuring data consistency and reliability. It also provides configurable persistence options to save data on disk. 3. Easy to use: eXtremeDB provides an easy-to-use API and Query language, enabling developers to easily manage and query data. It also supports multiple programming languages and provides rich development tools and documentation. Some drawbacks of eXtremeDB include: 1. Storage capacity limit: Since eXtremeDB is a In-memory database, its storage capacity is limited by the memory size. For large-scale datasets, additional storage devices may be required to support them. 2. Single machine limitation: Although eXtremeDB can be used as an independent database server, its scale is limited. For applications requiring Distributed database, other solutions may be required. The technical principle of eXtremeDB is based on B+tree index and Hash table. It uses memory as the main data storage, can read and write quickly, and provides powerful query and indexing capabilities. In addition, eXtremeDB also supports Multiversion concurrency control (MVCC) and Thread safety. Regarding performance analysis, eXtremeDB provides some performance monitoring and tuning tools, such as real-time monitoring, performance charts, and logging. Through these tools, developers can understand the operational status of the system and conduct performance analysis and optimization. The official website of eXtremeDB is: https://www.mcobject.com/extremedb To sum up, eXtremeDB is a high-performance and reliable In-memory database system, which is suitable for embedded and real-time systems. It has advantages such as fast read and write, ACID characteristics, and ease of use, but its small storage capacity and single machine limitations are some of its drawbacks. Through its technical principles based on B+tree index and Hash table, eXtremeDB provides powerful query and index capabilities.

GemStone/S is a scalable Object database system that supports highly reliable enterprise applications. The following is an introduction to the installation and use of GemStone/S, as well as sample code: 1. Install GemStone/S -Firstly, download the installation program for GemStone/S from the official website of GemTalk Systems and select the appropriate version according to the requirements of the operating system. -Run the installation program and follow the prompts to install. -During the installation process, you need to select the directory where GemStone/S is installed and provide a database name and administrator password. 2. Start GemStone/S -Find the script file to start GemStone/S in the installation directory and select the appropriate script based on the operating system. -Run the startup script and provide an administrator password to start the GemStone/S server. 3. Create a data table -Open the GemStone/S management tool, which can be the Command-line interface of GemStone/S or a graphical interface tool such as the GemStone/S Web browser. -Log in using an administrator account. -Create a data table using GemStone/S's Query language. The following is an example code: ``` class Person { firstName: String; lastName: String; age: Integer; } ``` -Run the above code to create a data table named Person. 4. Data insertion -Insert data using GemStone/S's Query language or programming interface. The following is an example code: ``` var person := Person new. person firstName: 'John'. person lastName: 'Doe'. person age: 30. person commit. ``` -Run the above code to insert a record into the Person data table. 5. Data modification -Use GemStone/S's Query language or programming interface to modify data. The following is an example code: ``` var person := Person fetchById: 1. person age: 31. person commit. ``` -Run the above code to modify the age of the record with ID 1 in the Person data table to 31. 6. Data Query -Use GemStone/S's Query language or programming interface to query data. The following is an example code: ``` var persons := Person allInstances. People do: [: each| each printString display. ]. ``` -Run the above code to query and display all records in the Person data table. 7. Data deletion -Use GemStone/S's Query language or programming interface to delete data. The following is an example code: ``` var person := Person fetchById: 1. person destroy. ``` -Run the above code to delete the record with ID 1 from the Person data table. The above is an introduction to the installation and use of the GemStone/S database, as well as sample code for creating data tables, inserting, modifying, querying, and deleting data. You can further learn and use the database based on actual needs and GemStone/S documentation.

ObjectDB is a Object database management system that supports Java objects as persistent data. The following is a detailed introduction to the installation and usage process of Object DB: 1. Download Object DB: Visit the official website of Object DB（ https://www.objectdb.com/ ）On the download page, select the version of Object DB that is suitable for your operating system. Object DB provides a version that can be integrated with Java EE containers, as well as a standalone version. After selecting the appropriate version, click the download button to download. 2. Install Object DB: After downloading, follow the installation steps to install. Usually, the installation of Object DB only requires extracting the downloaded files. 3. Create a data table: Open the Object DB Explorer in the Object DB suite (which can be found in the installation directory), connect to the database, or create a new database connection. In the console window, right-click on the database connection and select "Create Object DB Database". Then, enter the location and name of the database file, and click the "Save" button to save it. This creates a new Object DB database. 4. Implement data insertion: In the Object DB Explorer, right-click on the database connection and select "Open Object DB Console". In the open console window, enter Java code to implement data insertion. For example: ```java import javax.persistence.*; public class Main { public static void main(String[] args) { //Create Entity Manager Factory EntityManagerFactory emf = Persistence.createEntityManagerFactory("objectdb:your-database.odb"); //Create Entity Manager EntityManager em = emf.createEntityManager(); //Open transaction em.getTransaction().begin(); //Creating Entity Objects Person person = new Person("John Doe", 30); //Persisting Entity Objects to a Database em.persist(person); //Commit transaction em.getTransaction().commit(); //Close Entity Manager and Entity Manager Factory em.close(); emf.close(); } } ``` 5. Implement data modification: Use the entity manager of Object DB to update objects in the database. For example, you can modify the attribute values of a Person object and update them to the database: ```java // ... //Get Person Entity Object Person person = em.find(Person.class, personID); //Modifying Property Values of a Person Object person.setName("Jane Smith"); person.setAge(35); //Commit transaction em.getTransaction().commit(); // ... ``` 6. Realize data query: use ObjectDB's Query language (JPQL) to query objects in the database. For example, you can query the list of all Person objects in the database: ```java // ... //Create Query String queryString = "SELECT p FROM Person p"; Query query = em.createQuery(queryString); //Execute query and obtain results List<Person> persons = query.getResultList(); //Output query results for (Person person : persons) { System.out.println(person); } // ... ``` 7. Implement data deletion: Using the entity manager of Object DB, objects can be deleted from the database. For example, a Person object with a specified ID can be deleted: ```java // ... //Get Person Entity Object Person person = em.find(Person.class, personID); //Delete Person Object em.remove(person); //Commit transaction em.getTransaction().commit(); // ... ``` This is the basic installation and usage process of Object DB. Through the above steps, you can perform operations such as creating data tables, inserting data, modifying data, querying, and deleting data. According to actual needs, you can further understand its more advanced functions and usage methods based on the documentation of Object DB.