1 SELECT SUM(DATA_LENGTH)+SUM(INDEX_LENGTH) FROM information_schema.tables WHERE TABLE_SCHEMA='database_name'; 结果是以字节为单位,除1024为K,除1048576为M.   SELECT TABLE_NAME,DATA_LENGTH+INDEX_LENGTH,TABLE_ROWS FROM information_schema.tables WHERE TABLE_SCHEMA='…
原文地址:http://www.javacodegeeks.com/2015/07/mysql-vs-mongodb.html 1. Introduction It would be fair to say that as IT professionals we are living in the golden age of data management era. As our software systems become more complex and more distributed,…
I’m going to go over some methods to import data from text files into SQL Server today. The particular file I went out and grabbed is comma delimited and with a few qualifiers in it. It is a typical file you may get and a request made to import or ju…
LOAD DATA [LOW_PRIORITY | CONCURRENT] [LOCAL] INFILE 'file_name.txt' [REPLACE | IGNORE] INTO TABLE tbl_name [FIELDS [TERMINATED BY 'string'] [[OPTIONALLY] ENCLOSED BY 'char'] [ESCAPED BY 'char' ] ] [LINES [STARTING BY 'string'] [TERMINATED BY 'string…
mysql的“慢查询”指的是超过了允许的最大查询时间(long_query_time)的sql语句,而“未使用索引”查询顾名思义就是查询语句没有使用到索引的sql语句. 慢查询配置和使用 在msyqld的启动配置文件或命令行参数中增加以下参数 long_query_time=1 log-slow-queries=/var/mysql/logs/slow.log long_query_time参数表示的是慢查询的度量时间,单位是秒,最小是1,缺省值是10,凡是执行时间超过long_query_ti…
What is Spark Apache Spark is a cluster computing framework, similar to Apache Hadoop. Wikipedia has a great description of it: Apache Spark is an open source cluster computing framework originally developed in the AMPLab at University of California,…
load的语法 LOAD DATA [LOW_PRIORITY | CONCURRENT] [LOCAL] INFILE 'file_name.txt' [REPLACE | IGNORE] INTO TABLE tbl_name [FIELDS [TERMINATED BY 'string'] [[OPTIONALLY] ENCLOSED BY 'char'] [ESCAPED BY 'char' ] ] [LINES [STARTING BY 'string'] [TERMINATED BY…
Week 1 Data Science: An overview Objective: 1.Is data science the same as statistics or analysis? statistics analysis data science statistical analysis *analyzing the information of a sample. statistical analysis allowed to draw inference about targe…
mysql通过data目录恢复数据库 阅读:次   时间:2010-03-24 06:53:30   字体:[大 中 小]     重装系统后,MySQL服务没有了,但是数据库的文件还在,这个时候我想恢复以前的数据库, 起码要把数据导出来. MySQL重装N次,永远提示Could not start service error:0! 后来终于找到一个方儿,就是先把以前的库文件都拷贝出来,把以前的MySQL文 件全部清除,然后装个新的,这个时候MySQl可以正常启动了,然后在新的MySQL里建一个…
author: luciuz date: 2013/11/15 ----------------------------------------------------------------------------------------------------------------- 假定: 用户database:InsideTSQL2008, tablename:Employees 注意:如果需要导入的table “No primary key could be found”, 则需要“…