Database
Mysql Tutorial
Is Keyset Pagination a Better Alternative to SQL Server's OFFSET for Efficient Data Pagination?
Is Keyset Pagination a Better Alternative to SQL Server's OFFSET for Efficient Data Pagination?
Jan 16, 2025 am 10:57 AM
Beyond SQL Server OFFSET paging: the efficiency advantage of Keyset paging
Paging technology is crucial when dealing with large data sets, as it allows us to obtain specific parts of the data efficiently. Although SQL Server provides the OFFSET clause for paging, it has a performance bottleneck. This article will explore an alternative that performs better than OFFSET: Keyset paging.
Keyset paging: a better paging mechanism
Keyset paging adopts a more efficient mechanism than the row number-based Rowset paging used by OFFSET. Instead of reading all previous rows, it allows the server to directly access the correct location in the index, minimizing redundant reads.
To successfully implement Keyset paging, a unique index needs to be established on the primary key (and any other relevant columns). This enables the paging mechanism to navigate data based on primary keys rather than row numbers.
Advantages of Keyset paging
In addition to significant performance improvements, Keyset paging has other advantages:
- Avoid losing rows: Unlike OFFSET, it eliminates the risk of losing rows due to deletion as the primary key remains unchanged.
- Direct primary key access: It allows direct access to a specific primary key without the need for page estimation.
Keyset paging example
Suppose there is a table called 'TableName' with an index on the 'Id' column. The starting query for paging is as follows:
SELECT TOP (@numRows) * FROM TableName ORDER BY Id DESC;
Subsequent requests can retrieve the next page:
SELECT TOP (@numRows) * FROM TableName WHERE Id < (SELECT MAX(Id) FROM (SELECT TOP (@numRows) Id FROM TableName ORDER BY Id DESC) AS LastPage) ORDER BY Id DESC;
Notes on Keyset paging
- The selected primary key must be unique, or combined with other columns to ensure uniqueness.
- If the pagination primary key is not unique, additional columns should be included in the index and considered in the query.
- SQL Server does not support tuple comparators and requires specific comparisons when using non-unique primary keys.
Conclusion
For paging of large data sets, Keyset paging proves to be a superior alternative to SQL Server OFFSET. Its efficiency, direct primary key access, and ability to avoid missing rows make it ideal as the best data retrieval option in paging scenarios.
The above is the detailed content of Is Keyset Pagination a Better Alternative to SQL Server's OFFSET for Efficient Data Pagination?. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
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
1794
16
1739
56
1590
29
1467
72
267
587
Establishing secure remote connections to a MySQL server
Jul 04, 2025 am 01:44 AM
TosecurelyconnecttoaremoteMySQLserver,useSSHtunneling,configureMySQLforremoteaccess,setfirewallrules,andconsiderSSLencryption.First,establishanSSHtunnelwithssh-L3307:localhost:3306user@remote-server-Nandconnectviamysql-h127.0.0.1-P3307.Second,editMyS
Where does mysql workbench save connection information
Jun 26, 2025 am 05:23 AM
MySQLWorkbench stores connection information in the system configuration file. The specific path varies according to the operating system: 1. It is located in %APPDATA%\MySQL\Workbench\connections.xml in Windows system; 2. It is located in ~/Library/ApplicationSupport/MySQL/Workbench/connections.xml in macOS system; 3. It is usually located in ~/.mysql/workbench/connections.xml in Linux system or ~/.local/share/data/MySQL/Wor
How to add the MySQL bin directory to the system PATH
Jul 01, 2025 am 01:39 AM
To add MySQL's bin directory to the system PATH, it needs to be configured according to the different operating systems. 1. Windows system: Find the bin folder in the MySQL installation directory (the default path is usually C:\ProgramFiles\MySQL\MySQLServerX.X\bin), right-click "This Computer" → "Properties" → "Advanced System Settings" → "Environment Variables", select Path in "System Variables" and edit it, add the MySQLbin path, save it and restart the command prompt and enter mysql--version verification; 2.macOS and Linux systems: Bash users edit ~/.bashrc or ~/.bash_
Analyzing the MySQL Slow Query Log to Find Performance Bottlenecks
Jul 04, 2025 am 02:46 AM
Turn on MySQL slow query logs and analyze locationable performance issues. 1. Edit the configuration file or dynamically set slow_query_log and long_query_time; 2. The log contains key fields such as Query_time, Lock_time, Rows_examined to assist in judging efficiency bottlenecks; 3. Use mysqldumpslow or pt-query-digest tools to efficiently analyze logs; 4. Optimization suggestions include adding indexes, avoiding SELECT*, splitting complex queries, etc. For example, adding an index to user_id can significantly reduce the number of scanned rows and improve query efficiency.
Performing logical backups using mysqldump in MySQL
Jul 06, 2025 am 02:55 AM
mysqldump is a common tool for performing logical backups of MySQL databases. It generates SQL files containing CREATE and INSERT statements to rebuild the database. 1. It does not back up the original file, but converts the database structure and content into portable SQL commands; 2. It is suitable for small databases or selective recovery, and is not suitable for fast recovery of TB-level data; 3. Common options include --single-transaction, --databases, --all-databases, --routines, etc.; 4. Use mysql command to import during recovery, and can turn off foreign key checks to improve speed; 5. It is recommended to test backup regularly, use compression, and automatic adjustment.
Handling NULL Values in MySQL Columns and Queries
Jul 05, 2025 am 02:46 AM
When handling NULL values ??in MySQL, please note: 1. When designing the table, the key fields are set to NOTNULL, and optional fields are allowed NULL; 2. ISNULL or ISNOTNULL must be used with = or !=; 3. IFNULL or COALESCE functions can be used to replace the display default values; 4. Be cautious when using NULL values ??directly when inserting or updating, and pay attention to the data source and ORM framework processing methods. NULL represents an unknown value and does not equal any value, including itself. Therefore, be careful when querying, counting, and connecting tables to avoid missing data or logical errors. Rational use of functions and constraints can effectively reduce interference caused by NULL.
Resetting the root password for MySQL server
Jul 03, 2025 am 02:32 AM
To reset the root password of MySQL, please follow the following steps: 1. Stop the MySQL server, use sudosystemctlstopmysql or sudosystemctlstopmysqld; 2. Start MySQL in --skip-grant-tables mode, execute sudomysqld-skip-grant-tables&; 3. Log in to MySQL and execute the corresponding SQL command to modify the password according to the version, such as FLUSHPRIVILEGES;ALTERUSER'root'@'localhost'IDENTIFIEDBY'your_new
how to check mysql version on windows command prompt
Jul 01, 2025 am 01:41 AM
To check the MySQL version, you can use the following methods in the Windows command prompt: 1. Use the command line to view directly, enter mysql--version or mysql-V; 2. After logging in to the MySQL client, execute SELECTVERSION();; 3. Manually search through the installation path, switch to the MySQL bin directory and run mysql.exe--version. These methods are suitable for different scenarios, the first two are most commonly used, and the third one is suitable for situations where environment variables are not configured.
