Tag:Row level

  • 🍖 Transaction isolation mechanism

    Time:2021-10-21

    1、 Introduction to transaction isolation mechanism Transaction hasAtomicity, consistency, isolation, persistenceFour characteristics andIsolationAs the name suggests, transactions are isolated from each other. When multiple transactions process a data at the same time, they do not affect each other. If the isolation is not good enough, there may be problemsDirty reading, unrepeatable reading, phantom reading, etcphenomenon […]

  • MySQL — transaction

    Time:2021-10-16

    affair 1. Business understanding 1.1 concept of transaction Transaction processing can ensure that data oriented resources will not be updated forever unless all operations in the transactional unit are completed successfully. To become a transaction, a logical common unit must meet the so-called acid attribute, that is:1. Atomicity (a) For the modified data, either execute […]

  • Please check the classification of common storage engines and locks

    Time:2021-9-11

    In the last article, we mentioned record lock (row lock), gap lock and temporary key lock. A small partner in the background urged me to update other locks. Procrastination is happening again. Let’s summarize it today while we’re at the weekendMyISAMandInnoDBTypes and application methods of engine lower lock. Four common storage engines of MySQL talk […]

  • MySQL lock mechanism

    Time:2020-11-15

    Interior lock MySQL performs internal locking within its own server to manage contention for table content by multiple sessions. Internal lock can be divided into row lock and table lock. External lock MySQL provides options for client sessions to explicitly acquire table locks to prevent other sessions from accessing tables. You can use the lock […]

  • Understanding the row level lock of MySQL

    Time:2020-8-1

    1、 Definition One row of data is locked each time, and the locking mechanism is row level locking. Row level locking is not implemented by MySQL itself, but by other storage engines 2、 Advantages and disadvantages advantage Because of small lock granularity, low contention rate and high concurrency. shortcoming The implementation is complex and expensive. […]

  • Using database trigger to realize data synchronization

    Time:2020-7-9

    1、 What is a trigger A database trigger is a stored PL / SQL statement associated with a table. Whenever a specific data operation statement (insert update delete) is issued on the specified table, Oracle automatically executes the statement sequence defined in the trigger. The application scenarios of triggers are as follows: Complex security checks […]

  • [Mr. Zhao Qiang] using database trigger to realize data synchronization

    Time:2020-5-5

    1、 What is trigger Database trigger is a stored PL / SQL statement associated with a table. Whenever a specific data operation statement (insert update delete) is issued on the specified table, Oracle automatically executes the statement sequence defined in the trigger. The application scenario of the trigger is as follows: Complex security checks Confirmation […]

  • Almost kneeling in the face of database deadlock

    Time:2020-4-9

    Read the original: almost kneel in the face of database deadlock I don’t know if you have ever encountered the problem of database deadlock? Once encountered how to troubleshoot the problem? Environment: MySQL 5.7.25 engine InnoDB If your system log suddenly reports this kind of error, will you panic? Thought: MD, met before, but do […]

  • Database Storage Engine

    Time:2019-9-7

    Catalog Database Storage Engine What is a storage engine? What storage engines does MySQL support? Characteristics of various storage engines Common Storage Engines and Applicable Scenarios Interview questions Database Storage Engine What is a storage engine? Data in MySQL is stored in files (or memory) using various technologies. Each of these technologies uses different storage […]