U disk is one of the commonly used storage devices in our daily work and life, but sometimes we encounter situations where the U disk is write-protected and cannot write data. This article will introduce several simple and effective methods to help you quickly remove the write protection of the USB flash drive and restore the normal use of the USB flash drive. Tool materials: System version: Windows1020H2, macOS BigSur11.2.3 Brand model: SanDisk UltraFlair USB3.0 flash drive, Kingston DataTraveler100G3USB3.0 flash drive Software version: DiskGenius5.4.2.1239, ChipGenius4.19.1225 1. Check the physical write protection switch of the USB flash drive on some USB flash drives Designed with

PHP functions can realize the separation of business logic and data access. By encapsulating data access code in functions, the reusability, maintainability, testability and code separation of the code can be improved.

MySQL and MariaDB can coexist, but need to be configured with caution. The key is to allocate different port numbers and data directories to each database, and adjust parameters such as memory allocation and cache size. Connection pooling, application configuration, and version differences also need to be considered and need to be carefully tested and planned to avoid pitfalls. Running two databases simultaneously can cause performance problems in situations where resources are limited.

Schema in MySQL is a logical structure used to organize and manage database objects (such as tables, views) to ensure data consistency, data access control and simplify database design. The functions of Schema include: 1. Data organization; 2. Data consistency; 3. Data access control; 4. Database design.

The Service layer in Java is responsible for business logic and business rules for executing applications, including processing business rules, data encapsulation, centralizing business logic and improving testability. In Java, the Service layer is usually designed as an independent module, interacts with the Controller and Repository layers, and is implemented through dependency injection, following steps such as creating an interface, injecting dependencies, and calling Service methods. Best practices include keeping it simple, using interfaces, avoiding direct manipulation of data, handling exceptions, and using dependency injection.

Program performance optimization methods include: Algorithm optimization: Choose an algorithm with lower time complexity and reduce loops and conditional statements. Data structure selection: Select appropriate data structures based on data access patterns, such as lookup trees and hash tables. Memory optimization: avoid creating unnecessary objects, release memory that is no longer used, and use memory pool technology. Thread optimization: identify tasks that can be parallelized and optimize the thread synchronization mechanism. Database optimization: Create indexes to speed up data retrieval, optimize query statements, and use cache or NoSQL databases to improve performance.

Schema in MySQL is the logical structure of the database, which groups tables, views, stored procedures, and functions together. Schema is used to organize data, define data types and constraints, and control data access. To create a Schema, use CREATE SCHEMA <schema_name>, to use a Schema, use USE <schema_name>, and to delete a Schema, use DROP SCHEMA <schema_name>.

Steps to upload running data to Keep: 1. Connect the device and authorize data access; 2. Turn on automatic synchronization; 3. Manually upload data (if the device does not support automatic synchronization).