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MySQL vs MongoDB 1000 reads
...s://github.com/webcaetano/mongo-mysql
10 rows
mysql insert: 1702ms
mysql select: 11ms
mongo insert: 47ms
mongo select: 12ms
100 rows
mysql insert: 8171ms
mysql select: 10ms
mongo insert: 167ms
mongo select: 60ms
1000 rows
mysql insert: 94813ms (1.58 minutes)
mysql select: 13ms
mongo inser...
How do I quickly rename a MySQL database (change schema name)?
...y some developers. phpMyAdmin has an operation for this.
From phpMyAdmin, select the database you want to select. In the tabs there's one called Operations, go to the rename section. That's all.
It does, as many suggested, create a new database with the new name, dump all tables of the old databas...
Copy/duplicate database without using mysqldump
...the references, you can run the following to copy the data:
INSERT INTO x SELECT * FROM other_db.y;
If you're using MyISAM, you're better off to copy the table files; it'll be much faster. You should be able to do the same if you're using INNODB with per table table spaces.
If you do end up doin...
How to execute a bash command stored as a string with quotes and asterisk [duplicate]
...quotes.
MYSQL='mysql AMORE -u username -ppassword -h localhost -e'
QUERY="SELECT "'*'" FROM amoreconfig" ;# <-- "double"'single'"double"
eval $MYSQL "'$QUERY'"
Bonus: It also reads nice: eval mysql query ;-)
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What is the difference between UNION and UNION ALL?
...want the duplicates (especially when developing reports).
UNION Example:
SELECT 'foo' AS bar UNION SELECT 'foo' AS bar
Result:
+-----+
| bar |
+-----+
| foo |
+-----+
1 row in set (0.00 sec)
UNION ALL example:
SELECT 'foo' AS bar UNION ALL SELECT 'foo' AS bar
Result:
+-----+
| bar |
+---...
实战低成本服务器搭建千万级数据采集系统 - 更多技术 - 清泛网 - 专注C/C++...
...oncrawler上一篇文章《社会化海量数据采集框架搭建》提到如何搭建一个社会化采集系统架构，讲架构一般都比较虚，这一篇讲一下如何实战用低成本服务器...有这样一个采集系统的需求，达成指标： 需要采集30万关键词的数据 ...
django test app error - Got an error creating the test database: permission denied to create databas
...@localhost; I originally tried to only GRANT CREATE... but then could not SELECT or DROP the created database. This essentially makes your user a superuser, so be careful.
– mightypile
Dec 31 '15 at 16:28
...
What's the difference between RANK() and DENSE_RANK() functions in oracle?
...s a simple test script you can play with to see what happens:
with q as (
select 10 deptno, 'rrr' empname, 10000.00 sal from dual union all
select 11, 'nnn', 20000.00 from dual union all
select 11, 'mmm', 5000.00 from dual union all
select 12, 'kkk', 30000 from dual union all
select 10, 'fff', 4000...
淘宝大秒系统设计详解 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...进行动静分离，这也是解决大流量系统的一个重要原则。如何给系统做动静分离的静态化改造我以前写过一篇《高访问量系统的静态化架构设计》详细介绍了淘宝商品系统的静态化设计思路，感兴趣的可以在《程序员》杂志上找...
How to convert DateTime to VarChar
...yDateTime DATETIME
SET @myDateTime = '2008-05-03'
--
-- Convert string
--
SELECT LEFT(CONVERT(VARCHAR, @myDateTime, 120), 10)
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