Transaction Log File Transaction Log File, with the extension ldf, is a very important but often overlooked part of the database structure. It is a file used to record database updates. It can record any operation on the database and save the recorded results to a separate file. For each database update process, the transaction log file has a very comprehensive record. Based on these records, the state before the database update can be restored.
For performance reasons, SQL Server stores user changes in the cache. These changes will be written to the transaction log immediately, but not to the data file immediately. The transaction log uses a mark point to determine whether a transaction has written data from the cache to the data file. When SQL Server restarts, it will check the latest mark point in the log and erase the transaction records after this mark point, because these transaction records do not actually write the data in the cache to the data file. This prevents those interrupted transactions from modifying the data files.
All resources on this site are contributed by netizens or reprinted by major download sites. Please check the integrity of the software yourself! All resources on this site are for learning reference only. Please do not use them for commercial purposes. Otherwise, you will be responsible for all consequences! If there is any infringement, please contact us to delete it. Contact information: admin@php.cn
Related Article
Efficient approach to PHP error logging?09May2024
Effective PHP error logging method: use error_log(): log error messages to the system log. Use PSR-3Logger: Use a standardized logger interface to log different levels of log messages. Using Monolog: Take advantage of feature-rich libraries for log formatting, filtering, and output. Use Sentry: Automatically capture and report PHP errors, and provide event monitoring services.
05Jul2017
PHP encryption extension libraries include Mcrypt and Mhash. Among them, the Mcrypt extension library can implement encryption and decryption functions. Today we are talking about the functions and examples of Mcrypt.
PHP extension library comparison and performance test analysis of MQTT protocol08Jul2023
PHP extension library comparison and performance test analysis of MQTT protocol Abstract: With the rapid development of the Internet of Things, the MQTT protocol, as a lightweight message transmission protocol, is widely used in communication between Internet of Things devices. In the PHP field, in order to facilitate PHP developers to use the MQTT protocol, multiple MQTT PHP extension libraries have also emerged. This article will compare and perform performance test analysis of the current mainstream PHP extension libraries of the MQTT protocol, so as to choose the PHP extension library of the MQTT protocol that is suitable for your own project. Key words:
08Aug2016
:This article mainly introduces the PHP extension library. Students who are interested in PHP tutorials can refer to it.
PHP encryption extension library—Mcrypt extension library example usage25May2017
Before starting the main text of this article, let's first understand what the PHP encryption extension library is: There are not only several encryption functions (md5, crypt, sha1) in PHP, but also some encryption extensions with more comprehensive functions in PHP. Library! Just like PHP does not originally support operating a certain function, but if you want to support it in the new version, you can provide it in an extended way. In this way, when we configure PHP, if we do not use this function, we can prevent PHP from loading. It thus saves server resources and improves its performance.
Hot Tools
PHP library for dependency injection containers
PHP library for dependency injection containers
A collection of 50 excellent classic PHP algorithms
Classic PHP algorithm, learn excellent ideas and expand your thinking
Small PHP library for optimizing images
Small PHP library for optimizing images