Storage engines MySQL has several. You can change the default storage engine in the server configuration. Until MySQL 5.5.4, the default engine was. The main drawbacks of MyISAM are that it doesn’t support transactions or enforce foreign-key constraints.

SUBSTANCE: machine code access limitation method to resources, provided by the. (console, application with a graphical user interface or code library). We'll also describe how to restrict access to a web service using roles (through. Libuv: Written specifically for the Node multiplatform library in C. Libuv is able to.

On the plus side, it was the only engine that supported full-text indexing and searching until MySQL 5.6.4. Since MySQL 5.5.5, the default storage engine is. This engine is fully transactional and supports foreign key references. It’s probably the best choice at this point. However, note that the InnoDB autoincrement counter is lost on a MySQL restart because it does not remember the AUTO_INCREMENT value, instead recreating it as “max(id)+1”. This may result in an inadvertent reuse of values. If you upgrade an existing project to MySQL 5.5.5 and subsequently add some tables, ensure that your tables are using the same storage engine (i.e.

Specifically, if tables that have a ForeignKey between them use different storage engines, you may see an error like the following when running migrate. MySQL DB API Drivers The Python Database API is described in. MySQL has three prominent drivers that implement this API: • is a native driver that has been developed and supported for over a decade by Andy Dustman. • is a fork of MySQLdb which notably supports Python 3 and can be used as a drop-in replacement for MySQLdb. At the time of this writing, this is the recommended choice for using MySQL with Django.

• is a pure Python driver from Oracle that does not require the MySQL client library or any Python modules outside the standard library. All these drivers are thread-safe and provide connection pooling.

MySQLdb is the only one not supporting Python 3 currently. In addition to a DB API driver, Django needs an adapter to access the database drivers from its ORM. Django provides an adapter for MySQLdb/mysqlclient while MySQL Connector/Python includes. Collation settings The collation setting for a column controls the order in which data is sorted as well as what strings compare as equal. G n berman reshebnik los angeles.

It can be set on a database-wide level and also per-table and per-column. This is in the MySQL documentation. In all cases, you set the collation by directly manipulating the database tables; Django doesn’t provide a way to set this on the model definition.

By default, with a UTF-8 database, MySQL will use the utf8_general_ci collation. This results in all string equality comparisons being done in a case-insensitive manner.

That is, 'Fred' and 'freD' are considered equal at the database level. If you have a unique constraint on a field, it would be illegal to try to insert both 'aa' and 'AA' into the same column, since they compare as equal (and, hence, non-unique) with the default collation. In many cases, this default will not be a problem. However, if you really want case-sensitive comparisons on a particular column or table, you would change the column or table to use the utf8_bin collation. The main thing to be aware of in this case is that if you are using MySQLdb 1.2.2, the database backend in Django will then return bytestrings (instead of unicode strings) for any character fields it receive from the database. This is a strong variation from Django’s normal practice of always returning unicode strings. It is up to you, the developer, to handle the fact that you will receive bytestrings if you configure your table(s) to use utf8_bin collation.

Django itself should mostly work smoothly with such columns (except for the contrib.sessions Session and contrib.admin LogEntry tables described below), but your code must be prepared to call django.utils.encoding.smart_text() at times if it really wants to work with consistent data – Django will not do this for you (the database backend layer and the model population layer are separated internally so the database layer doesn’t know it needs to make this conversion in this one particular case). If you’re using MySQLdb 1.2.1p2, Django’s standard class will return unicode strings even with utf8_bin collation. However, fields will be returned as an array.array instance (from Python’s standard array module). There isn’t a lot Django can do about that, since, again, the information needed to make the necessary conversions isn’t available when the data is read in from the database. This problem was, so if you want to use with utf8_bin collation, upgrading to version 1.2.2 and then dealing with the bytestrings (which shouldn’t be too difficult) as described above is the recommended solution. Should you decide to use utf8_bin collation for some of your tables with MySQLdb 1.2.1p2 or 1.2.2, you should still use utf8_general_ci (the default) collation for the django.contrib.sessions.models.Session table (usually called django_session) and the table (usually called django_admin_log).