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Is there any performance gain in indexing a boolean field?
...e an index, if you have too many records it doesn't use the index anyways.
MySQL not using index when checking = 1 , but using it with = 0
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Node.js vs .Net performance
...ization
nodejs: 228,887
aspnet-stripped: 105,272
Single Query
nodejs-mysql: 88,597
aspnet-stripped-raw: 47,066
Multiple Queries
nodejs-mysql: 8,878
aspnet-stripped-raw: 3,915
Plain Text
nodejs: 289,578
aspnet-stripped: 109,136
In all cases, Node.js tends to be 2x+ faster than IIS.
...
How to implement the activity stream in a social network
...s to browse far back in time (if you even offer this)
I use a plain old MySQL table for dealing with about 15 million activities.
It looks something like this:
id
user_id (int)
activity_type (tinyint)
source_id (int)
parent_id (int)
parent_type (tinyint)
time ...
How to import multiple .csv files at once?
...
+1 seems like producing a single data frame -- the SQL UNION of all CSV files -- is the easiest to work with. Since OP didn't specify whether they want 1 data frame or many data frames, I assumed 1 data frame is best, so I am surprised the accepted answer does not do any of the "...
How to pull a random record using Django's ORM?
...e backend you're using." - any experience on diffrent DB backends? (sqlite/mysql/postgres)?
– kender
Jun 8 '09 at 9:37
4
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BIO与NIO、AIO的区别(这个容易理解) - 操作系统(内核) - 清泛网 - 专注C/C++及内核技术
...给OS处理，需要将数据缓冲区地址和大小传给OS(银行卡和密码)，OS需要支持异步IO操作API）；
阻塞 ： ATM排队取款，你只能等待（使用阻塞IO时，Java调用会一直阻塞到读写完成才返回）；
非阻塞 ： 柜台取款，取个号，然后坐在...
What is SQL injection? [duplicate]
...d queries, or applying your language/toolkit's escaping functions (such as mysql_real_escape_string() in PHP).
Once you understand SQL Injection you'll get the joke behind this cartoon.
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String isNullOrEmpty in Java? [duplicate]
...that when I tried to use StringUtils my IDE (Eclipse) imported it from com.mysql.jdbc.StringUtils which actually has an isNullOrEmpty(myStringObject) method.
ex.
import com.mysql.jdbc.StringUtils;
StringUtils.isNullOrEmpty(host)
Just another alternative for those who already have the MySQL conne...
Good Free Alternative To MS Access [closed]
...ess, you generally want a database server engine, like MS SQL, Postgresql, MySQL, Oracle, or their brethren. At the same time, those server engines are rarely if ever appropriate for a single-user desktop application.
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SQL WHERE condition is not equal to?
...uple of times.. but it didn't seem to work until I realized that DELETE in MySQL does not use the * ..
– Frank Vilea
May 27 '11 at 19:59
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