MyISAM is transactionless and heap-organized. The records are identified by the row offset in the table and the indexes store this offset as a row pointer. InnoDB supports transactions and is index-organized. The records are identified by the value of the PRIMARY KEY (or a hidden internal column is there is no PRIMARY KEY defined) … Read more
Replace TYPE=MyISAM with ENGINE=MyISAM The problem was “TYPE=MyISAM” which should be “ENGINE=MyISAM” as per MySQL version updates – a simple search / replace has fix it.
Kindly tell me, In this situation what engine I have to use for improve performance? The performance of each storage engine will depend on the queries you perform. However, be aware that different tables within the same database can use different storage engines. Why MyISAM engine does not support foreign key relationship and InnoDB does? … Read more
SHOW TABLE STATUS WHERE Name=”xxx” This will give you (among other things) an Engine column, which is what you want.
MySQL uses only table-level locking from MyISAM tables. If you can, switch to InnoDB for row-level locking. Here’s a link to the MySQL site describing Locks set by SQL Statements for InnoDB tables. http://dev.mysql.com/doc/refman/5.0/en/innodb-locks-set.html
MyISAM effectively works in auto-commit mode (as it’s not a transactional engine), and it just ignores the commit/rollback. Actually storage engine is a different layer in the MySQL architecture, separated from the SQL parser, the SQL layer communicates to the storage engine with lower-level API, and that’s the reason there is a common SQL and … Read more
The main difference is that InnoDB supports transactions while MyISAM does not. There are numerous other differences, however the common one’s i am aware of are: MyISAM has typically been considered faster at searching, but recent InnoDB improvements are removing this difference and improving high concurrency workload performance InnoDB support transactions whilst MyISAM does not … Read more
The main differences between InnoDB and MyISAM (“with respect to designing a table or database” you asked about) are support for “referential integrity” and “transactions”. We choose InnoDB if we need the database to enforce foreign key constraints or support transactions (i.e. changes made by two or more DML operations handled as single unit of … Read more
You make a good point that you can avoid some number of joined queries by using what’s called a natural key instead of a surrogate key. Only you can assess if the benefit of this is significant in your application. That is, you can measure the queries in your application that are the most important … Read more
I would use a composite (multi-column) key. CREATE TABLE INFO ( t1ID INT, t2ID INT, PRIMARY KEY (t1ID, t2ID) ) This way you can have t1ID and t2ID as foreign keys pointing to their respective tables as well.