extremeDB列数据库常见问题（1）
1. 金融版中除了自带的数学函数，是否支持自定义函数？ 支持自定义函数。此外 索引， Error handle 等也支持自定义函数。 2. 金融版中锁的机制是怎么样的？ 根据事务模式的不一样，锁的颗粒度不一样。如 MVCC 在数据和索引上都有锁。 3. 金融版的列式数据是
1.金融版中除了自带的数学函数，是否支持自定义函数？
支持自定义函数。此外索引，Error handle等也支持自定义函数。
2.金融版中锁的机制是怎么样的？
根据事务模式的不一样，锁的颗粒度不一样。如MVCC在数据和索引上都有锁。
3.金融版的列式数据是以什么类型存储到磁盘的？是否可以单独的1列或者2列的数据存储，而不是所有数据存储到一起？
列数据需要以页的形式存储的；With a columnar layout, a database page (the unit of storage indatabase systems) only contains values for that one column and no othercolumns.
4.在金融版中，一级二级缓存的大小的分配是自动分配还是用户自己做？
The block (tile) size is implemented withineXtremeDB so that the elements in a single block will fit into the CPU cache.
5. Kdb中，可以将一列数据存在一个文件中，你们数据库是如何存储？
以页为单位存储。不能指定存储文件，但可以分担io性能，使用多文件.
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
iOS 18 adds a new 'Recovered' album function to retrieve lost or damaged photos
Jul 18, 2024 am 05:48 AM
Apple's latest releases of iOS18, iPadOS18 and macOS Sequoia systems have added an important feature to the Photos application, designed to help users easily recover photos and videos lost or damaged due to various reasons. The new feature introduces an album called "Recovered" in the Tools section of the Photos app that will automatically appear when a user has pictures or videos on their device that are not part of their photo library. The emergence of the "Recovered" album provides a solution for photos and videos lost due to database corruption, the camera application not saving to the photo library correctly, or a third-party application managing the photo library. Users only need a few simple steps
Detailed tutorial on establishing a database connection using MySQLi in PHP
Jun 04, 2024 pm 01:42 PM
How to use MySQLi to establish a database connection in PHP: Include MySQLi extension (require_once) Create connection function (functionconnect_to_db) Call connection function ($conn=connect_to_db()) Execute query ($result=$conn->query()) Close connection ( $conn->close())
Summary of FAQs for DeepSeek usage
Feb 19, 2025 pm 03:45 PM
DeepSeekAI Tool User Guide and FAQ DeepSeek is a powerful AI intelligent tool. This article will answer some common usage questions to help you get started quickly. FAQ: The difference between different access methods: There is no difference in function between web version, App version and API calls, and App is just a wrapper for web version. The local deployment uses a distillation model, which is slightly inferior to the full version of DeepSeek-R1, but the 32-bit model theoretically has 90% full version capability. What is a tavern? SillyTavern is a front-end interface that requires calling the AI model through API or Ollama. What is breaking limit
How to handle database connection errors in PHP
Jun 05, 2024 pm 02:16 PM
To handle database connection errors in PHP, you can use the following steps: Use mysqli_connect_errno() to obtain the error code. Use mysqli_connect_error() to get the error message. By capturing and logging these error messages, database connection issues can be easily identified and resolved, ensuring the smooth running of your application.
Top 10 Global Digital Virtual Currency Trading Platform Ranking (2025 Authoritative Ranking)
Mar 06, 2025 pm 04:36 PM
In 2025, global digital virtual currency trading platforms are fiercely competitive. This article authoritatively releases the top ten digital virtual currency trading platforms in the world in 2025 based on indicators such as transaction volume, security, and user experience. OKX ranks first with its strong technical strength and global operation strategy, and Binance follows closely with high liquidity and low fees. Platforms such as Gate.io, Coinbase, and Kraken are at the forefront with their respective advantages. The list covers trading platforms such as Huobi, KuCoin, Bitfinex, Crypto.com and Gemini, each with its own characteristics, but investment should be cautious. To choose a platform, you need to consider factors such as security, liquidity, fees, user experience, currency selection and regulatory compliance, and invest rationally
How does Go WebSocket integrate with databases?
Jun 05, 2024 pm 03:18 PM
How to integrate GoWebSocket with a database: Set up a database connection: Use the database/sql package to connect to the database. Store WebSocket messages to the database: Use the INSERT statement to insert the message into the database. Retrieve WebSocket messages from the database: Use the SELECT statement to retrieve messages from the database.
How to use database callback functions in Golang?
Jun 03, 2024 pm 02:20 PM
Using the database callback function in Golang can achieve: executing custom code after the specified database operation is completed. Add custom behavior through separate functions without writing additional code. Callback functions are available for insert, update, delete, and query operations. You must use the sql.Exec, sql.QueryRow, or sql.Query function to use the callback function.
How to handle database connections and operations using C++?
Jun 01, 2024 pm 07:24 PM
Use the DataAccessObjects (DAO) library in C++ to connect and operate the database, including establishing database connections, executing SQL queries, inserting new records and updating existing records. The specific steps are: 1. Include necessary library statements; 2. Open the database file; 3. Create a Recordset object to execute SQL queries or manipulate data; 4. Traverse the results or update records according to specific needs.
