set autocommit

Write in front: indexes have a critical impact on the speed of queries, and understanding indexes is also a starting point for database Performance tuning. Consider the following scenario, assuming that a table in the database has 10^6 records, the

Source: ReprintMySQL's transactional support is not tied to the MySQL server itself, but is related to the storage engine 1. MyISAM: Transaction not supported, for read-only program lift high performance 2.InnoDB: Acid transaction support, row level

Write in front: indexes have a critical impact on the speed of queries, and understanding indexes is also a starting point for database Performance tuning. Consider the following scenario, assuming that a table in the database has 10^6 records, the

Look at a SQL first, the last SQL output what do you think it is?SET autocommit = 1; Begin;insert into T1 VALUES (1); CREATE TABLE T2 (PK int primary key); INSERT into T2 VALUES (2); ROLLBACK; SHOW TABLES;The answer is: T1, t2 all exist!Mysql> Show

In general, read/write operations in MyISAM are serial, but when querying and inserting the same table, to reduce the frequency of lock competition, according to the settings of concurrent_insert, myISAM can process queries and inserts in

Welcome to the Linux community forum and interact with 2 million technical staff to access the table structure first, engine innodb + ---- + ---------- + ------ + | id | name | seat | + ---- + ---------- + ------ + | 1 | administrator | 98 | 2 |

Insert statement Syntax: insert into table [(column1, column2. ..)] values (value1, value2 ...); Note: An insert statement can insert only one record to a table at a time. When you list the default field names, you should explicitly set new values

Even if the autoReconnecttrue parameter is added to the url when Mysql is created, the connection time exceeds the server wait_timeout time limit, Even if the autoReconnect = true parameter is added to the url when Mysql is created, the connection

Why does the database require ImplictCommit (implicit commit of transactions) First look at an SQL statement. What do you think is the output of the last SQL statement? SET AUTOCOMMIT = 1;BEGIN;INSERT INTO t1 VALUES (1);CREATE TABLE t2 (pk int

Differences between MyISAM and InnoDB $ Content = "MySQL supports several storage engines as processors for different table types. MySQL storage engine includes the engine for processing transaction security tables and the engine for processing

Transaction processing is widely used in various management systems. For example, in the personnel management system, many synchronous database operations require transaction processing. For example, in the personnel management system, if you delete

Insert statement Syntax: insertintotable [(column1, column2. ..)] values (value1, value2...); Description: The insert statement can only insert one record to the table at a time. When the default field name list is used, you should explicitly set a

The following articles mainly introduce the performance tests of MySQL MyISAM engine and InnoDB engine. The MyISAM engine and InnoDB engine are often used in actual operations, the following article describes the performance tests of MySQL MyISAM

Cause: There is an InnoDB Engine table, which is executed in a foreach loop of about 3000 times.Insert into table (Columna, columnb) values (valuea, valueb) The results exceed the 60 s PHP Execution limit (which can be modified in PHP. INI), which

Start transaction,COMMIT, AndROLLBACKSyntax From: http://dev.mysql.com/doc/refman/5.0/en/commit.html Of course, the article noted from MySQL, but MySQL, SQL Server, Oracle start tracmsaction, commit, and rollback syntax are no problem in DML. I hope

Preface: indexes have a crucial impact on the query speed. Understanding indexes is also the starting point for optimizing database performance. Consider the following: Assume that a table in the database has 10 ^ 6 records, the page size of the

MySQL experience 10-1-transaction 1. In the MySQL environment, a transaction is composed of one or more SQL statements as a separate unit. Each SQL statement in this unit is mutually dependent, and the Unit as a whole is inseparable. If a statement

MYSQL's pseudo-row locks have always assumed that the row-level locks supported by mysql's innodb engine are the same as those supported by oracle and postgresql, and are used to lock data rows. But it is actually different. Different understandings

In the InnoDB engine, there are roughly three row-level locks in MySQL: recordlock, Gap, and next-keylocks. Recordlock is used to lock a row of records, while gap locks the records in a range. Next-keylocks is the effect of the first two. The

The previous article talked about the daily maintenance commands of Linux and the daily maintenance commands of oracle. I believe that Oracle databases must be maintained more or less. Should I import and export Oracle databases? (Oh, you said you