If MySQL reports an error number 1005 from a CREATE TABLE statement, and the error message refers to error 150, table creation failed because a foreign key constraint was not correctly formed. Similarly, if an ALTER TABLE fails and it refers to error 150, that means a foreign key definition would be . Error: 1005 … Read more
Error: 1064 SQLSTATE: 42000 (ER_PARSE_ERROR) Message: %s near ‘%s’ at line %d Error #1064 means that MySQL can’t understand your command. To fix it: Read the error message. It tells you exactly where in your command MySQL got confused. Check the manual. By comparing against what MySQL expected at that point, the problem is often … Read more
Error: 1008 SQLSTATE: HY000 (ER_DB_DROP_EXISTS) Message: Can’t dropp database ‘%s’; database doesn’t exist
MySQL Error: 1040 SQLSTATE: 08004 (ER_CON_COUNT_ERROR) If you get a too many connections error,Error: 1040 SQLSTATE: 08004 (ER_CON_COUNT_ERROR), when you try to connect to the mysqld server, this means that all available connections are in use by other clients. To increase the concurrent connections what are allowed to connect to the server, change the max_connections … Read more
What is database? Database is an organized collection of information about an entity having controlled redundancy and serves multiple applications. DBMS (database management system) is an application software that is developed to create and manipulate the data in database. A query language can easily access a data in a database. SQL (Structured Query Language) is … Read more
The idea behind partitioning isn’t to use multiple servers but to use multiple tables instead of one table. You can divide a table into many tables so that you can have old data in one sub table and new data in another table. Then the database can optimize queries where you ask for new data … Read more
The busiest file in the InnoDB infrastructure is /var/lib/mysql/ibdata1 This file normally houses many classes of information (when innodb_file_per_table is 0) Table Data Table Indexes MVCC (Multiversioning Concurrency Control) Data Rollbacks Segments Undo Tablespace Table Metadata Many people create multiple ibdata files hoping for better diskspace management and performance. It does not help. Unfortunately, OPTIMIZE TABLE against … Read more