Environment construction1, to Apache download SOLR, Address: http://mirrors.hust.edu.cn/apache/lucene/solr/2. Unzip to a directory3. CD into D:\Solr\solr-4.10.3\example4. Execute the server by "Java-jar Startup.jar" SOLR will automatically run on
Describes how to use mysql to create an index and its advantages and disadvantages.
Preface
Index is a data structure that helps MySQL efficiently obtain data. It is critical for high performance, but people often forget or misunderstand it. The
Advantages and disadvantages of building indexes:Why do you create an index?This is because creating an index can greatly improve the performance of the system.First, by creating a unique index, you can guarantee the uniqueness of each row of data
Index functionIn addition to the ordered lookups mentioned above, the database uses a variety of fast location techniques to greatly improve the query efficiency. In particular, when the amount of data is very large and the query involves more than
http://blog.csdn.net/superit401/article/details/51291603Advantages and disadvantages of building indexes:Why do you create an index?This is because creating an index can greatly improve the performance of the system.First, by creating a unique index,
Create a unique index using SQL statements in the following format: Create unique index name on table name (column name 1, column Name 2 ...) For example, create a unique index ix_goodsmade_labour on the SID column of table Goodsmade_labour, with
One, MySQL commonly used commands:1. Connect to the database: mysql>mysql-uroot-p Enter, then passwordMysql-h 192.168.0.200-p 3306-u root-p2. mysql>status; View Run Environment information3. Show all databases: show databases;4. Switch the database
Mysql Optimization in CentOS1. debug mysql Command method: mysql> explain select * from t1 \ G or: mysql> desc select * from t1 \ G mainly to view the following attributes:(1) Whether index is used for type(2) key Index name(3) number of rows
Advantages of creating an index in MySQL: 1. greatly accelerating data retrieval; 2. Creating a unique index to ensure the uniqueness of each row of data in the database table; 3. Accelerating the connection between tables
Advantages of creating an
Mysql adds and deletes the field type, mysql Field
Add a MySQL field:
Alter table 'user _ movement_log 'Add column GatewayId int not null default 0 AFTER 'regionid' (AFTER which field is added)
Delete field:
alter table `user_movement_log` drop
Database index: Role of database index
Advantages of index creation:
1. Greatly speed up data retrieval;
2. Create a unique index to ensure the uniqueness of each row of data in the database table;
3. Accelerate the connection between tables;
4.
MySQL adds a field: altertable 'user _ movement_log 'comment 'regionid' (after which field is added) Delete the field: altertable 'user _ movement_log' dropcolumnGatewayid adjust the field order: ALTERTABLE 'user _ movement_lo
MySQL adds a field:
How does MYSQL add an index bitsCN.com?
How to add an index for MYSQL
1. add the primary key (primary key index)
Mysql> alter table 'Table _ name' add primary key ('column ')
2. add UNIQUE (UNIQUE index)
Mysql> alter table 'Table _
One, createCREATE Index to add a normal or unique index to a table.CREATE INDEX index_name ON table_name (column_list)CREATE UNIQUE INDEX index_name ON table_name (column_list)1) Build Multiple indexesCREATE INDEX Table Name _ Field name 1_ field
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.