大约有 48,000 项符合查询结果（耗时：0.0658秒） [XML]
What is a columnar database?
... simply storing the info in tables with one (or rather often two) columns (and adding the necessary layer to access the columnar data in an easy fashion).
How do they differ from relational databases?
They generally differ from traditional (row-oriented) databases with regards to ...
performance....
How to escape special characters in building a JSON string?
... edited Jun 21 '16 at 1:12
Andrew
11.9k88 gold badges6666 silver badges9090 bronze badges
answered Oct 4 '13 at 7:56
...
How to run multiple Python versions on Windows
I had two versions of Python installed on my machine (versions 2.6 and 2.5). I want to run 2.6 for one project and 2.5 for another.
...
Build an iOS app without owning a mac? [closed]
...ases
iPhone/iPad (iOS) app development
iPhone/iPad (iOS) app development and Publish to iTunes Store
1. iPhone/iPad (iOS) app development
So If you just want to develop iOS apps you don't want to pay anything,
You just need Mac + XCode IDE
Get Mac Mini or Mac Machine
Create Developer Accoun...
Find row where values for column is maximal in a pandas DataFrame
...
Use the pandas idxmax function. It's straightforward:
>>> import pandas
>>> import numpy as np
>>> df = pandas.DataFrame(np.random.randn(5,3),columns=['A','B','C'])
>>> df
A B ...
What's the best practice for primary keys in tables?
...signing tables, I've developed a habit of having one column that is unique and that I make the primary key. This is achieved in three ways depending on requirements:
...
How to strip all non-alphabetic characters from string in SQL Server?
...t dbo.RemoveNonAlphaCharacters('abc1234def5678ghi90jkl')
Once you understand the code, you should see that it is relatively simple to change it to remove other characters, too. You could even make this dynamic enough to pass in your search pattern.
Hope it helps.
...
How serious is this new ASP.NET security vulnerability and how can I workaround it?
...you always should anyways in release/production mode.
Additionally add a random time sleep in the error page to prevent the attacker from timing the responses for added attack information.
In web.config
<configuration>
<location allowOverride="false">
<system.web>
<c...
Difference between setTimeout with and without quotes and parentheses
I am learning JavaScript and I have learned recently about JavaScript timing events. When I learned about setTimeout at W3Schools , I noticed a strange figure which I didn’t run into before. They are using double quotes and then call the function.
...
Why is Java Vector (and Stack) class considered obsolete or deprecated?
... deprecated its a legacy class.There must be difference between deprecated and legacy and yes there is see stackoverflow.com/questions/2873254/…
– Prashant Shilimkar
Dec 23 '13 at 6:23
...