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Multiple columns index when using the declarative ORM extension of sqlalchemy
...f you have a dictionary for table_args like I currently do? table_args = {'mysql_engine':'InnoDB'}
– Nick Holden
Sep 1 '11 at 8:39
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Random record in ActiveRecord
...selected entries. (Be aware that it's RANDOM() in PostgreSQL and RAND() in MySQL ... not as portable as you may want it to be.)
– Florian Pilz
Jun 16 '11 at 13:17
3
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Which is fastest? SELECT SQL_CALC_FOUND_ROWS FROM `table`, or SELECT COUNT(*)
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It depends. See the MySQL Performance Blog post on this subject: To SQL_CALC_FOUND_ROWS or not to SQL_CALC_FOUND_ROWS?
Just a quick summary: Peter says that it depends on your indexes and other factors. Many of the comments to the post seem to...
提升大数据分析思想，拥抱大数据未来 - 资讯 - 清泛网 - 专注C/C++及内核技术
...务和世界范围内产生的数据。而所谓公司的麻烦是指，该如何正确利用这些数据——判断出哪些才是相关的、有用的，哪些是需要过滤掉的。最重要的是，哪些才是有助于推动业务发展的。”
因此，思想转变的第一步应是观察...
How do you list all triggers in a MySQL database?
What is the command to list all triggers in a MySQL database?
4 Answers
4
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When and why are database joins expensive?
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MySQL, Oracle, SQL Server, Sybase, postgreSQL,etc. care not the order of joins. I've worked with DB2 and it also, to my knowledge, doesn't care what order you put them in. This is not helpful advice in the general case
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What can you use Python generator functions for?
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Real World Example
Let's say you have 100 million domains in your MySQL table, and you would like to update Alexa rank for each domain.
First thing you need is to select your domain names from the database.
Let's say your table name is domains and column name is domain.
If you use SELECT...
How to disable and re-enable console logging in Python?
...an answer as blocking propagation effectively disables all handlers of the root logger and the question clearly states (…) but I may have other handlers there that I want to keep which suggests the intention is to disable default StreamHandler of the root logger only.
– Piotr...
MySQL: Invalid use of group function
I am using MySQL. Here is my schema:
2 Answers
2
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MFC CListCtrl使用方法详解 - C/C++ - 清泛网 - 专注C/C++及内核技术
... Programmatically
http://support.microsoft.com/kb/131284/en-us
19. 如何在CListView中使用CListCtrl的派生类
http://www.codeguru.com/cpp/controls/listview/introduction/article.php/c919/
20. listctrl的subitem添加图标
m_list.SetExtendedStyle(LVS_EX_SUBITEMIMAGES);
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