The main difference between MySQL and Oracle is licenses, features, and advantages. 1. License: MySQL provides a GPL license for free use, and Oracle adopts a proprietary license, which is expensive. 2. Function: MySQL has simple functions and is suitable for web applications and small and medium-sized enterprises. Oracle has powerful functions and is suitable for large-scale data and complex businesses. 3. Advantages: MySQL is open source free, suitable for startups, and Oracle is reliable in performance, suitable for large enterprises.

The key to learning Java without taking detours is: 1. Understand core concepts and grammar; 2. Practice more; 3. Understand memory management and garbage collection; 4. Join online communities; 5. Read other people’s code; 6. Understand common libraries and frameworks; 7. Learn to deal with common mistakes; 8. Make a learning plan and proceed step by step. These methods can help you master Java programming efficiently.

Learning SQL requires mastering basic knowledge, core queries, complex JOIN operations and performance optimization. 1. Understand basic concepts such as tables, rows, and columns and different SQL dialects. 2. Proficient in using SELECT statements for querying. 3. Master the JOIN operation to obtain data from multiple tables. 4. Optimize query performance, avoid common errors, and use index and EXPLAIN commands.

Learning Java requires learning basic syntax, object-oriented programming, collection frameworks, exception handling, multithreading, I/O streaming, JDBC, network programming, and advanced features such as reflection and annotation. 1. The basic syntax includes variables, data types, operators and control flow statements. 2. Object-oriented programming covers classes, objects, inheritance, polymorphism, encapsulation and abstraction. 3. The collection framework involves ArrayList, LinkedList, HashSet, and HashMap. 4. Exception handling ensures program robustness through try-catch block. 5. Multithreaded programming requires understanding of thread life cycle and synchronization. 6. I/O streams are used for data reading, writing and file operations. 7. JDBC is used to interact with databases. 8. Network programming passes S

To connect Oracle database to Tableau for data visualization, you need to follow the following steps: 1. Configure Oracle database connection in Tableau, use ODBC or JDBC drivers; 2. Explore data and create visualizations, such as bar charts, etc.; 3. Optimize SQL queries and indexes to improve performance; 4. Use Oracle's complex data types and functions to implement through custom SQL queries; 5. Create materialized views to improve query speed; 6. Use Tableau's interactive functions such as dashboard for in-depth analysis.

Common SQL statements include: 1. CREATETABLE creates tables, such as CREATETABLEemployees(idINTPRIMARYKEY, nameVARCHAR(100), salaryDECIMAL(10,2)); 2. CREATEINDEX creates indexes, such as CREATEINDEXidx_nameONemployees(name); 3. INSERTINTO inserts data, such as INSERTINTO employeees(id, name, salary)VALUES(1,'JohnDoe',75000.00); 4. SELECT check

UseRedisinsteadofatraditionaldatabasewhenyourapplicationrequiresspeedandreal-timedataprocessing,suchasforcaching,sessionmanagement,orreal-timeanalytics.Redisexcelsin:1)Caching,reducingloadonprimarydatabases;2)Sessionmanagement,simplifyingdatahandling

In Oracle database, the steps to configure parallel query to improve performance include: 1. Set at the database level, and implement it by modifying initialization parameters such as PARALLEL_DEGREE_POLICY and PARALLEL_MAX_SERVERS; 2. Set at the session level, adjust the parallelism of the current session through the ALTERSESSION command; 3. Consider key points such as parallelism, resource management and data distribution; 4. Improve performance by optimizing query planning, adjusting parallelism and monitoring and tuning. These steps help to take full advantage of parallel queries and significantly improve the query performance of the database.