MySQL Study notes Day Fourth

MySQL Engine:
Archive (archives) [data insertion cannot be modified after, read-only]
blackhole[This write operation is to delete the data, the read operation is to return a blank record]
Csv[a comma as a delimiter between data items when storing data]
example[example (stub) storage engine]
falcon[the type of storage used to process transactions]
Federated[the storage engine used to access remote data tables]
innodb[transaction engine with foreign key support]
memory[in-memory data sheet]
Merge[A collection of data tables that are used to manage multiple MyISAM data tables (MERG-MYISAM)]
MyISAM Default Storage type
Ndb[mysql Clustor Special Engine]

Part II:
No_engine_substitution settings do not use the default engine (not successful when creating a data table type)
Use Default-storage-engine to start the server with a default storage engine
Show CREATE TABLE Table_name=select condition from information_schema.tables[view default engine]
Using the min-rows=n to optimize the memory engine
eg
CREATE TABLE table_name{...} Engine=memory min-rows=100;
Control the size of the MyISAM using Max-rows and Avg-row-length
Changing the data table engine: ALTER TABLE table_name TYPE[ENGINE]=TYPE_NAME
Use if not exist to create a table to check for the same table, but at a certain risk, use the drop table if exist to execute the CREATE table

Temp table:
Creating a temporary table: Create temporary table table_name (also supports a variety of engines), the life cycle of a temporary table is typically the server stops staging table type
You can have the same name as a permanent table, but a permanent table is temporarily invalidated until the temporary table loses its effect.

use like and select to create new data tables from other data tables
CREATE TABLE table_name as _table_name so that new data tables are created with the same type, index, order ,
INSERT INTO table_name SELECT ... [Insert table data or other data after select], you can use this method to create a
temporary copy: Temporary
inserts additional table data into the copy eg:insert into new_table_name select * from Ta Ble_name[where ...]; The
uses the CREATE TABLE table_name Select to one step the above two types, but the data in this case may be indexed or may lose data properties

provides a clear definition in the CREATE TABLE section, and then the Select section uses those definitions to retrieve:

select I as I,cast (Curtime () as time) as T,-----------------(this passage does not read the meaning = =.) )
ps:select Sentence Select fill in data requirements.

Merge data sheet:
The merge handles MyISAM as a connection unit, and each member of a merge data table has the same order, data type, index, etc.
eg
CREATE TABLE Log_ccyy
(dt datetime NOT NULL,
Info varchar (+) NOT NULL,
Index (DT)
);
Ccyy is the meaning of the year, assuming the creation of the log_2010,log_2011, after creating a merge type:
CREATE TABLE Log_merge
(DT datetime Notnull,
Info varchar (+) NOT NULL
Index (DT)

) Engine=merge union= (log_2010,log_2011)
　　　　[Insert_method=[no\first\last]];
When creating a new merge unit (MyISAM table type), the inserted position first or last or no does not allow inserting a new data table
Log_merge Add data Table log_2012:
ALTER TABLE log_merge= (LOG_2010,LOG_2011,LOG_2012)