how to build relational database in mysql

Tags: type SQL statement Delete Insert Number unique index explain not slow query1, positioning slow query-find out the execution slow SQL.2, suitable table structure, appropriate engine, index, partition table, SQL optimization (single machine Optimization).3, Multi-machine optimization--read/write separation (cluster), distributed.4, the cache scheme.Parsing slow query: Explain + SQL statement "using MySQL client"Indexes are at the expense of insert

Label:MongoDB Grammar MySQL syntax Db.test.find ({' name ': ' Foobar '}) Db.test.find () Db.test.find ({' ID ': ten}). Count () Db.test.find (). Skip () Limit Db.test.find ({' ID ': {$in: [25,35,45]}} Db.test.find (). Sort ({' ID ': -1}) Db.test.distinct (' name ', {' ID ': {$lt:}}) Db.test.group ({key:{' name ': ' true},cond:{' name ': ' foo '},reduce:function (obj,prev) {prev.msum+=obj.marks;},initial: {msum:0}}) Db.test.find (' this.id D

number, manufacturer's name, component number, and manufacturer's address, but also manufacturer's name, the manufacturer's address, so there is a non-primary attribute transfer dependency on the main attribute, which does not conform to the third normal form requirementAfter modification:BC Paradigm: Based on the first paradigm, each non-trivial dependency must have a key code on the left side, and each determinant must contain a key code. Wikis: Any property, including non-primary and primary

Tags: type brackets unique order Chinese word breaker query files multiple columnsImprove query speed, facilitate sorting and grouping. (The process of sorting and grouping, if not indexed, results in temporary tables and filesort)Based on business logic, analyze the frequency and order of column queries, and build indexes and composite indexes.Primary key index (primary key),----> No index name is required because there is only one primary key indexU

Some basic usage MySQL and MongoDB design instance comparison: http://www.51testing.com /? Uid-116228-action-viewspace-itemid-241061 MongoDB common methods: http://blog.csdn.net/cppbegginer/article/details/6968522 MongoDB database installation and PHP connection test on Windows: http://hi.baidu.com/zyrym1989/blog/item/60f9154fb1df84d5d0c86ab0.html MongoDB advanced query: http://www.cnblogs.com/cxd4321/archi

1.sqoop importing data from hive into MySQLFor example:Sqoop export--connect jdbc:mysql://10.18.101.15:3306/wda--username restdbuser--password 123456--table adl_trend_num _android--export-dir/apps/hive/warehouse/adldb.db/adl_trend_num_android/date_stamp= $date-- Input-fields-terminated-by ' \ t '2.sqoop importing data from MySQL into hiveFor example: sqoop Import--connect jdbc:mysql://192.168.66.96:3306/sqoop--username sqoop--password sqoop -- Table S

number of data tables, which still makes it difficult to build a data model that simulates the real world. And when the data need to make the report output, but also the scattered set of a large number of two-dimensional data table, and then use the index technology to connect the table, can find all the required data, which will inevitably affect the application system response speed.3. Limitations on Scaling scalability:The ability of

ManagerPermissions and integrity ManagerThings ManagerFile ManagerBuffer ManagerQuery ManagerDML InterpreterDDL interpreterQuery execution engineSingle-process multi-threading, daemon thread, application threadRelational operations:Projection: Output only the specified attribute columnSelect: Output only the specified record lineNatural joins: Rows with the same value on all property values with the same nameCartesian product;and the set operation.SQL query statement:DdlDmlDCLHow to interact wi

Label:The sqoop2-1.99.4 and sqoop2-1.99.3 versions operate slightly differently: The new version uses link instead of the old version of connection, which is similar to other uses.sqoop2-1.99.4 Environment Construction See: SQOOP2 Environment Constructionsqoop2-1.99.3 version Implementation see: SQOOP2 Import relational database data to HDFsTo start the sqoop2-1.99.4 version of the client:$SQOOP 2_home/bin/

Label: #!/bin/Sh./etc/Profile SqoopImport#连接--connect \"Jdbc:mysql://192.168.1.107:3306/test"#用户名--username root# Password--Password123456#使用多少个Map-m\1#如果有null用‘‘Alternative--NULL-string‘‘#Mysql的表名--Table User #字段--Columns"Id,host,user,password"#可加条件--where ID=108#Hbase的表名--hbase-table AA #列族--column-Family CF #那一列字段作为rowkey呢? --hbase-row-Key ID The ID of a relational d