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by: Westcoast Sheri |
last post by:
Which will be a faster lookup of an item by, "color" in the following
mySQL tables: "unique key," "primary key," or just plain "key"??
CREATE TABLE myTable (
number int(11) NOT NULL default '0',
description varchar(50) NOT NULL default '',
color varchar(30) NOT NULL default '',
price decimal(3,2) NOT NULL default '0.00',
UNIQUE KEY (color)
);
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by: Philip Yale |
last post by:
I'm probably going to get shot down with thousands of reasons for
this, but I've never really heard or read a convincing explanation, so
here goes ...
Clustered indexes are more efficient at returning large numbers of
records than non-clustered indexes. Agreed? (Assuming the NC index
doesn't cover the query, of course)
Since it's only possible to have one clustered index, why is this
almost always used for the primary key, when by...
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by: Gary |
last post by:
Hi,
I am a Chinese student, I have a problem with the following code
//The follwing code in StaticSearch.h:
//
template <class Type> class dataList;
//
template <class Type> class Node //Êý¾Ý±íÖнáµãÀàµÄ¶¨Òå
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by: sfh |
last post by:
Greetings all,
I have a question concerning primary key types.
In the past, I have always created tables with a primary key as an "int" such as:
CREATE TABLE color_id (
color_id int(10) unsigned NOT NULL auto_increment primary key,
color varchar(45) default NULL
) TYPE=INNODB DEFAULT CHARSET=latin1;
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by: sfh |
last post by:
Greetings all,
(I had posted this in MS SQL on accident, my apologies :( )
I have a question concerning primary key types.
In the past, I have always created tables with a primary key as an "int" such as:
CREATE TABLE color_id (
color_id int(10) unsigned NOT NULL auto_increment primary key,
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by: Craig O'Shannessy |
last post by:
Hi all,
Just thought I'd mention that I really think this problem needs to be
fixed. I
I'm patching the 7.4RC1 JDBC drivers as we speak due to this optimiser
bug, and it's the third time I've had to do this. I would think this bug
causes quite a lot of people to evaluate postgres and decide it has awful
primary key performance! I love postgres, and hate to think that this
could be happening.
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by: Jerry |
last post by:
Is that true that one table can only have one clustered index? The
column with clustered index will be sorted physically, is that true?
The column with non-clustere index will not be sorted physically, is
that true?
Also, is primary key clustered index by default?
Thanks!
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by: LurfysMa |
last post by:
Most of the reference books recommend autonum primary keys, but the
Access help says that any unique keys will work.
What are the tradeoffs?
I have several tables that have unique fields. Can I use them as
primary keys or should I define an autonum primary key?
One table has information about the 50 states in the US. The table
looks like this:
|
by: George2 |
last post by:
Hello everyone,
I am wondering the default implementation of assignment operator (e.g.
when we do not implement assignment operator in user defined class,
what will be returned? temporary object? reference or const reference?
deep copy or shallow copy is used in default assignment operator?)? I
have the C++ Programming Book at hand, but can not find it from Index
page.
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by: Hystou |
last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can effortlessly switch the default language on Windows 10 without reinstalling. I'll walk you through it.
First, let's disable language synchronization. With a Microsoft account, language settings sync across devices. To prevent any complications,...
|
by: Oralloy |
last post by:
Hello folks,
I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>".
The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed.
This is as boiled down as I can make it.
Here is my compilation command:
g++-12 -std=c++20 -Wnarrowing bit_field.cpp
Here is the code in...
|
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by: jinu1996 |
last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven tapestry of website design and digital marketing. It's not merely about having a website; it's about crafting an immersive digital experience that captivates audiences and drives business growth.
The Art of Business Website Design
Your website is...
|
by: Hystou |
last post by:
Overview:
Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For most users, this new feature is actually very convenient. If you want to control the update process,...
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by: tracyyun |
last post by:
Dear forum friends,
With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
|
by: agi2029 |
last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing, and deployment—without human intervention. Imagine an AI that can take a project description, break it down, write the code, debug it, and then launch it, all on its own....
Now, this would greatly impact the work of software developers. The idea...
|
by: conductexam |
last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one.
At the time of converting from word file to html my equations which are in the word document file was convert into image.
Globals.ThisAddIn.Application.ActiveDocument.Select();...
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by: TSSRALBI |
last post by:
Hello
I'm a network technician in training and I need your help.
I am currently learning how to create and manage the different types of VPNs and I have a question about LAN-to-LAN VPNs.
The last exercise I practiced was to create a LAN-to-LAN VPN between two Pfsense firewalls, by using IPSEC protocols.
I succeeded, with both firewalls in the same network. But I'm wondering if it's possible to do the same thing, with 2 Pfsense firewalls...
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by: muto222 |
last post by:
How can i add a mobile payment intergratation into php mysql website.
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