What is the difference between mysql and oracle

The differences between mysql and oracle are: mysql is an open source project and does not charge a fee, while oracle requires a fee. Mysql defaults to automatic submission but oracle does not. Mysql's syntax is more flexible while oracle's syntax is strict, etc.

For For many small projects, MySQL database can basically meet the needs of various functions. However, as the amount of data increases, MySQL gradually becomes overwhelmed. At this time, Oracle database is needed. Next, This article will give you a detailed introduction to the differences between the two, which will serve as a reference and I hope it will be helpful to you.

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The difference between mysql and oracle

(1) Project nature

MySQL is an open source project and does not charge any fees, while Oracle is an This mature database product is closed source and also charges a fee

(2) Submission of transactions

MySQL defaults to automatic submission, while Oracle defaults to It is not submitted automatically. Users need to submit manually. They need to write the commit command or click the commit button

(3) SQL syntax is different

MySQL’s SQL syntax is more flexible, while Oracle's syntax is relatively strict

(4) Paging query

MySQL directly writes "select... from ...where...limit" in the SQL statement x, y", paging can be achieved with limit; while Oracle needs to use pseudo column ROWNUM and nested query

(5) Support for transactions

MySQL can only support transactions with the row-level lock of the innodb storage engine, while Oracle fully supports transactions

(6) Durability of saved data

MySQL will lose data after the database is updated or restarted, and Oracle writes the submitted sql operation line into the online online log file and keeps it on the disk, which can be restored at any time

(7) Thread The difference

MySQL is a single process and multi-threaded, while Oracle is a multi-process (also a single process under Windows). Similar to the difference between Windows operating system and Linux operating system, under Windows only one user can be used, or you can switch between different users, while under Linux, multiple users or the same user can connect to the operating system at the same time.

(8) Permissions and security

MySQL users are related to the host, and it is easy to be counterfeited. The host and IP can be exploited; while Oracle’s permissions and security The concept is relatively traditional and quite satisfactory.

(9) Partitioned table and partitioned index

MySQL’s partitioned table is not yet mature and stable, while Oracle’s partitioned table and partitioned index functions are very mature and can be improved User experience of accessing db

(10) Concurrency

MySQL mainly uses table-level locks, and the granularity of resource locking is very large. If a session locks a table If the locking time is too long, other sessions will be unable to update the data in this table.

Oracle uses row-level locks, and the granularity of resource locking is much smaller. It only locks the resources required by SQL, and the locking is on the data rows in the database and does not rely on indexes. So Oracle's support for concurrency is much better.

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