The data _____ component of a database management system (DBMS) is used to add, delete, modify, and retrieve records from a database

Answers

Answer 1

The data manipulation component of a database management system is used to add, retrieve, delete, and modify records from a database.

Database Management Systems (DBMS) are referred as to software systems that store, retrieve, and execute data queries. A database management system acts as a bridge between an end-user and a database, allowing users to create, edit, read, and remove data in the database. The data manipulation is the underlying component that a database management system uses to add, retrieve, delete, and modify records from a database.

You can learn more about database management system at

https://brainly.com/question/24027204

#SPJ4


Related Questions

Which of the following is not one of the techniques used in web mining?
a.Content mining
b.Structure mining
c.Server mining
d.Usage mining
e.Data mining

Answers

Web mining does not use server mining as one of its methods. group recent bitcoin transactions into "blocks," then strive to solve cryptographic puzzles to verify each block and ensure the ledger entries are accurate.

Which of the subsequent methods is utilized for web content mining?

Natural language processing (NLP) and information retrieval (IR) are the technologies that are typically employed in web content mining (Information Retrieval). The goal of web structure mining is to glean valuable information from the structure and linkages.

What are the four principal data mining methods?

Association, classification, clustering, prediction, sequential patterns, and regression are only a few of the primary data mining techniques that have been developed and employed in recent projects.

To know more about server mining visit :-

https://brainly.com/question/16965673

#SPJ4

Answer: data mining

Explanation: you can't do that with a web in mine craft

A researcher wants to conduct a secondary analysis using a Centers for Disease Control (CDC) database of prostate cancer patients that was collected by the agency. The researcher was not part of the original database creation and the database was originally created to monitor public health and not for research purposes. The database is publicly available. The database does not include any identifiers. Consent from the patients is not required because: The researcher did not collect the data directly from the human subjects. The researcher proposes to study a disease that affects public health. The database is publicly available. The CDC is a federal agency.

Answers

The researcher does not need to obtain consent from the patients because the data in the CDC database was not collected directly by the researcher and is publicly available. Additionally, the proposed research study relates to a disease that affects public health, which is a valid reason for using the data without obtaining consent.

It's important to note, that even though the database does not include any identifiers and is publicly available, it is still important for the researcher to comply with relevant laws and regulations regarding data protection, such as HIPAA in the United States. Additionally, the researcher should also follow ethical guidelines for secondary data analysis, such as ensuring that the data is used for a valid research purpose, that the analysis is conducted in a transparent manner, and that any limitations or potential biases in the data are acknowledged and addressed in the research.

Learn more about database, here https://brainly.com/question/30087281

#SPJ4

Which tool would be the best choice to remove and replace the motherboard BIOS chip?
A. IC extractor
B. Screwdriver
C. Needle-nose plier
D. Combination ratchet

Answers

The BIOS, which stands for Basic Input/Output System and is pronounced bye-oss, is a ROM chip that is present on motherboards that enables you to access and configure your computer system at the most fundamental level.

Can I swap out the BIOS chip?

Even though your BIOS cannot be flashed, you can still update it if the chip is placed in a socketed DIP or PLCC chip. The current chip must be physically removed and either replaced after being reprogrammed with the newer BIOS code or exchanged for a brand-new chip.

What takes place if the BIOS chip is harmed?

This initial program cannot be correctly launched and a computer cannot start if the BIOS chip on the motherboard is broken or corrupted.

To know more about BIOS visit :-

https://brainly.com/question/3364065

#SPJ4

the programmer design tool used to design the whole program is the flowchart blackbox testing gets its name from the concept that the program is being tested without knowing how it works

Answers

The programmer design tool used to design the whole program is the flowchart is false and blackbox testing gets its name from the concept that the program is being tested without knowing how it works is true.

What tools are used for designing programs?

Flowcharting, hierarchy or structure diagrams, pseudocode, HIPO, Nassi-Schneiderman diagrams, Warnier-Orr diagrams, etc. are a few examples. The ability to comprehend, use, and create pseudocode is demanded of programmers. Most computer classes typically cover these techniques for creating program models.

How and when is black box testing used?

Any software test that evaluates an application without having knowledge of the internal design, organization, or implementation of the software project is referred to as "black box testing." Unit testing, integration testing, system testing, and acceptance testing are just a few of the levels at which black box testing can be carried out.

To know more about design tool visit

brainly.com/question/20912834

#SPJ4

8.3.5: Max In List
Write the function max_int_in_list that takes a list of ints and returns the biggest int in the list. You can assume that the list has at least one int in it. A call to this function would look like:

my_list = [5, 2, -5, 10, 23, -21]
biggest_int = max_int_in_list(my_list)
# biggest_int is now 23
Do not use the built-in function max in your program!

Hint: The highest number in the list might be negative! Make sure your function correctly handles that case.

Answers

Answer:

here!!

Explanation:

# Write code here...

def max_int_in_list(my_list):

   highest = my_list[4]

   

   for num in my_list:

       if num > highest:

           highest = num

       return highest

my_list = [5, 2, -5, 10, 23, -21]

biggest_int = max_int_in_list(my_list)

print biggest_int

A version of the required program written in python 3 is given below.

my_list = [5, 2, -5, 10, 23, -21]

def max_int_in_list(my_list):

#iniate the function named max_int_in_list which takes in a list argument

maximum = my_list[0]

#set the first value in the list as maximum

for num in my_list:

#iterate through every value in the list

if num > maximum:

#Check if any of the iterated values in the list is greater than the set maximum value

maximum = num

#if so set the Number as the new maximum value

return maximum

#return the maximum value

print(max_int_in_list(my_list))

A SCREENSHOT of the program output is attached.

Learn more on python programs :https://brainly.com/question/24782250

One of the main reasons for copyright law is to encourage creators to share their work for the benefit of the general public.

Answers

To encourage creators to share their work for the benefit of the broader public is one of the primary goals of copyright law. Any person may use any piece of work that is in the public domain.

What does the Copyright Law's primary goal?

The ownership, use, and dissemination of artistic and expressive works are regulated by copyright laws. People believe that the majority of creators produce their creative works in order to get compensated in this economic story regarding copyright.

What does copyright law say about a work that is normally covered by copyright?

According to American copyright law, copyright owners have the following exclusive rights: Make copies or phonorecords of the work. Create works based on the original work. distribute phonorecords or copies of the material.

To know more about copyright law visit:-

https://brainly.com/question/29738132

#SPJ4

You decide to work late on a Saturday night to replace wiring in your server room. Upon arriving, you realize that a break-in has occurred and server backup tapes appear to be missing. What should you do as law enforcement officials arrive

Answers

As soon as law enforcement personnel show up, you should inform authorities that there is surveillance video on the property.

When handling a situation involving a data breach or data loss Chain of custody is defined.

Definitions: A procedure that keeps track of the transfer of evidence throughout its lifespan of collection, storage, and analysis by recording each individual who handled the evidence, the day and time it was gathered or moved, and the reason for the transfer

Which Soar component automates the reaction to security incidents involving IT?

What SOAR component is used to automate the response to security incidents involving IT? D. Security orchestration, automation, and response (SOAR) is a software program created to improve the effectiveness of incident response by speeding up reaction times.

To know more about law enforcement personnel  visit :-

https://brainly.com/question/12570740

#SPJ4

When using ________ addressing, a computer is assigned an address from a pool of available IP addresses.

Answers

Using Dynamic Host Configuration Protocol, networks assign dynamic IP addresses (DHCP). The most used method for allocating addresses is DHCP.

What does IP address addressing mean?

A device on the internet or a local network can be identified by its IP address, which is a special address. The rules defining the format of data delivered over the internet or a local network are known as "Internet Protocol," or IP.

What is an IP address, and where can I find my computer's IP address?

Every computer, server, or other internet-connected device is given a unique number identification known as an IP address.

To know more about IP addresses visit:-

https://brainly.com/question/16011753

#SPJ4

what are the 5 ways of controlling hazards and risk? explian each

Answers

Answer:

1 Eliminate the hazard. Remove it completely from your workplace.

2 Substitute the hazard.

3 Isolate the hazard.

4 Use engineering controls.

5 Use administrative controls.

6 Use personal protective equipment (PPE)

Explanation:

Help, this question is confusing. The hexadecimal equivalent of 22210 is DE. The binary equivalent of D7 is 11010011. The decimal of 1316 is 19. (Just if u can’t read it good. ) true or false

Answers

The hexadecimal equivalent of 22210 is DE is a True Statement. The binary equivalent of D7 is 11010011 is False Statement. The decimal of 1316 is 19 is a True Statement.

a) 22210 is DE

To do this, we use the product rule to convert DE from base 16 to base 10.

We thus have:

[tex]DE_{16} = D * 16^{1} + E * 16^{0}[/tex]

So hexadecimal

D = 13

E = 14

[tex]DE_{16} = 13 * 16^{1} + 14 * 16^{0}[/tex]

[tex]DE_{16} = 222_{10}[/tex] So the statement is True

b) D7 is 11010011

First, apply the product rule to convert D7 to base 10

[tex]D7_{16} = D * 16^{1} + 7 * 16^{0}[/tex]

D = 13

[tex]D7_{16} = 13 * 16^{1} + E * 7^{0}[/tex]

[tex]D7_{16} = 215_{10}[/tex]

So the statement is false

c) 1316 is 19

[tex]13_{16} = 1 * 16^{1} + 3 * 16^{0}[/tex]

[tex]13_{16} = 19[/tex]

Hence the option c statement is True

To learn more about hexadecimal

https://brainly.com/question/13041189

#SPJ4

give examples of special purpose computer​

Answers

Answer:

A few examples are home appliance controllers, weapon controllers, boiler temperature controllers, fuel injection systems in automobile engines, etc.

Explanation:

Special-purpose computers are designed for one specific task or class of tasks and wouldn't be able to perform general computing tasks. For example, a router is a special-purpose computer designed to move data around a network, while a general-purpose computer can be used for this task, as well as many others.

Explanation:

home appliance controllers, weapon controllers, boiler temperature controllers,

what utility will help you move your data email applications and settings from your old Windows computer to

Answers

You can backup user account files and settings using the Windows Easy Transfer function. When you have a new computer, you can transfer those files and settings over.

How can I move my apps from my old computer to my new Windows 10 machine?

direct file transfer using a USB device, You may attach an external hard drive to your old PC, copy your files to it, eject the device from the old computer, plug it into your new PC, and repeat the process.

What is the quickest method for moving files across computers?

Using an external hard drive is the simplest method for transferring data from one PC to another.

To know more about Windows visit :-

https://brainly.com/question/13502522

#SPJ4

Describe the connection between computer science and travel.

Answers

I tried to research but this is all I got I hope this helps in a way

You can right-click the target cell or cells and then select the option or press the keys to paste the copied data.

Answers

We may use the copy and paste choices from the drop-down menu by performing a right click on it. The shortcuts for copy are Ctrl + C for copy and Ctrl + V for paste if we want to perform it using the keyboard and shortcuts.

Which two methods are used to copy data?

For copying, press Ctrl + C, and for pasting, press Ctrl + V. 2. Choose the cell that you wish to duplicate. Select the cell on which you wish to paste it by selecting it with the right click and selecting Copy.

What in Excel is data copying?

The data from the chosen cell stays in its original position when you copy a cell, and it is also added to a temporary storage space called the Clipboard.

To know more about copied data visit:

https://brainly.com/question/28874482

#SPJ4

how do I answer other peoples question. is there something to click because i dont see it.

Answers

If you’re using the app, cick on the question you want to answer and press “answer” at the bottom of the screen.

Answer:

yes , it should say right there "answer question" press that usually it has a plus sign on it.

Explanation:

if you find this helpful please like it and rate it :D

Nathan wants TRUE to be elicited if either of the statements are true, and FALSE if both are true. Which of the following formula can he use to ensure that

Answers

Nathan wants TRUE to be elicited if either of the statements is true, and FALSE if both are true. The formula C:=XOR(...) can be used to ensure that.

The XOR Function is available under Excel Logical functions. The XOR Function is a logical 'exclusive OR' function. For the two given logical statements, the working of the XOR Function is as follows:

The XOR function would return 'TRUE' if one of the given statements is true and The XOR function would return 'FALSE' if both statements are true.

Thus, Nathan should use XOR Function to meet her specified purpose.

"

Complete question:

Nathan wants TRUE to be elicited if either of the statements are true, and FALSE if both are true. Which of the following formula can he use to ensure that?

a. =IFERROR(...)

b. =IFNA(...)

c. =XOR(...)

d. =TRUE OR FALSE(...)

"

You can leanr more about The XOR function at

https://brainly.com/question/26680966

#SPJ4

A controversial program rewards prison inmates who behave particularly well in prison by giving them the

Answers

The controversial program rewards prison inmates who behave particularly well in prison by offering them the opportunity to reduce their sentence.

Reducing Prison Sentences Through Positive Behavior

This program rewards inmates who demonstrate good behavior, such as following prison rules, participating in rehabilitation programs, and taking part in work programs. This program is intended to help inmates transition back into society by giving them an incentive to follow the rules and turn their lives around. Ultimately, this reduces recidivism and helps inmates become productive members of society.

Learn more about Sentences: https://brainly.com/question/552895

#SPJ4

You are no longer required to manually enter this when you install Windows 10. a. User name b. Product key c. Password d. Microsoft account

Answers

When installing Windows 10, you are no longer necessary to manually type this.

Without a product key, how do you install Windows 10?

Click or press "I don't have a product key" when the Windows 10 setup procedure asks you to activate Windows at that point. After that, carry out a regular installation of Windows 10 since the setup wizard won't ask for the product key again.

What exactly is a Windows 10 product key?

A product key is a 25-character code used to activate Windows and ensure that it hasn't been installed on any more computers than the Microsoft Software License Terms permit.

To know more about installing Windows visit :-

https://brainly.com/question/24282472

#SPJ4

Can anyone help me with this question?
What are Object Query Languages?

Answers

it is an object oriented database that is modeled after the SQL. hope that helps :)

Answer:

Object Query Languages (OQL) are query languages used to access, query, and manipulate data stored in an object-oriented database. OQL is similar to SQL, but it is tailored to the object-oriented model, allowing queries to be written in terms of objects and their relationships. OQL queries are commonly used to retrieve and modify data stored in an object-oriented database, as well as to perform operations such as creating and dropping objects and classes.

6. A Salesforce user at Universal Containers has been deactivated. What will happen to the records the user owns in Salesforce

Answers

For the records, ownership will remain unchanged. Still, the inactive user will be linked to records.

How is the linked license handled when a user account is deactivated?

The number of user licenses available to your organization is not affected by a deactivated user. However, deleting a user doesn't affect how many licenses your company is charged for. You must alter the license count for your company in order to alter billing.

Are accounts that have been deactivated deleted?

When you deactivate an account, it is not completely deleted. In the event that you decide to reactivate your account, F acebook keeps all of your preferences, pictures, and information when you deactivate your account. Your data is still there; it's just buried.

To know more about ownership visit :-

https://brainly.com/question/14480423

#SPJ4

How to get rid of the error ""Microsoft has blocked macros from running because the source is untrusted""?

Answers

The simplest method to unlock macros for a specific item, for example a file obtained from the internet or an email the customer has save to their local disk, is to uninstall Mark of the Web.

What is Microsoft's updated  status?

Bill Gates owns 14 million Windows interests, or 340 million stakeholder votes. The value of Bill Gates' holdings in Windows was until December 2021 was $35 billion. Bill Gates, as William H.

How do I get immediate contact with Microsoft customer service?

in order to obtain assistance numbers. Please mark a post as beneficial if you found it to be so and rate it. This will make things easier for other users to find answers to similar problems.

To know more about Microsoft visit :

https://brainly.com/question/26599006

#SPJ4

Other parts of a web page that a search engine robot may examine include: a. The title, meta tag descriptions and some text within the web page. b. The background page color c. The types of fonts used within the web page
d. The operating system it was developed on.

Answers

The solution is Option (A), the page's title, meta tag descriptions, and some internal text.

What do you mean by a web page?

A browser may see a simple document known as a web page. These publications were made utilizing the HTML coding language. Every new website can contain a wide range of resources, such as style information, which controls the page's look and feel.

What sets a webpage apart from a website?

What sets a website apart from a webpage? A webpage is a written message on the internet with a unique URL, whereas a website is a collection of several websites with information solely on a single or more themes tied together.

To know more about web page visit :

https://brainly.com/question/15851835

#SPJ4

A user carries a laptop between a home network and a business network. While on the business network the user requires a static IP (Internet Protocol) address. When at home, DHCP (Dynamic Host Configuration Protocol) is used to obtain an address. The user often forgets how to switch the laptop settings between the two, and then has trouble using the laptop online. What type of configuration can be used to help the user

Answers

A configuration that can be utilized to assist the user is an alternate address.

Which of the following presents a security risk following the installation of a new app on a mobile device?

Storage of data. The data that you save on the device and whether other apps can access it is the most frequent security worry for Android applications.

Which of the following techniques for erasing data requires electromagnetic disturbance?

By disrupting the magnetic field of an electronic medium with a strong magnet, degaussing obliterates computer data. Data is destroyed when the magnetic field is disturbed. A gadget that stores a lot of information or sensitive data can be swiftly and efficiently destroyed by degaussing.

To know more about alternate address visit :-

https://brainly.com/question/16830963

#SPJ4

If you use the _______________ switch, ping continuously sends ping packets until you stop it with the break command.

Answers

The break command can be used to stop ping from sending ping packets if you use the -t switch (CTRL-C).

What does ping packet mean?

IP packets are sent to an IP address as part of the ping command's connectivity test. ICMP, or Internet Control Message Protocol, is utilized. more specifically, the ICMP echo request and echo reply messages. The use of TCP or UDP is not required by ICMP. As the source address, the router selects the IP address of the outgoing interface.

The switch of a LAN is connected to the following network by what device?

It is possible to join two or more logically and physically distinct networks using a router, which is a network communication device. A LAN can be connected to another LAN, a LAN to a WAN, or the internet using a router.

To know more about break command visit :-

https://brainly.com/question/28334510

#SPJ4

The _____ button is located on the Title bar of the word window ( start/ office)​

Answers

I think it is the office button sorry if not


Identity any five system unit components and explain the use for each [apart from processor]

Answers

Answer:

RAM

ROM

PROCESSOR

MOTHER BOARD

HARD DISK

Explanation:

Random access memory or RAM store data temporary

Read only memory or ROM permanently store data and have a programming needed to start (PCs) or other electronic device

CPU or processor refers to brain of computer

Mother board the main internal hardware component of system unit

Hard disk is electro mechanical data storage

Match each word to its correct meaning. 1 . images displayed on the screen that enables the user to interact with the computer; abbreviated GUI central processing unit 2 . physical parts of a computer, such as the motherboard or hard disk file 3 . breaks in the action of a program using the operating system graphical user interface 4 . core program of a computer operating system hardware 5 . the chip than runs the basic operations of the computer; abbreviated CPU interrupts 6 . a collection of data, such as a program or document kernel 7 . format for storage of digital data memory

Answers

Images displayed on the screen that enables the user to interact with the computer; abbreviated GUI graphical user interface.

What are the names of the actual components of a computer?

Hardware refers to a computer system's actual physical parts. It is a group of actual hardware components for a computer system. A computer chassis, monitor, keyboard, and mouse are included.

Physical parts of a computer, such as the  hard disk file are Computer hardware .Breaks in the action of a program using the graphical user interface (GUI)Core program of a computer operating system .The chip than runs the basic operations of the computer;CPUA collection of data, such as Database.Format for storage of digital data memory are files, blocks, and objects.

To learn more about graphical user interface refer to:

https://brainly.com/question/14758410

#SPJ4

What type of methodology works well to ensure that all agents are given and hear the same information

Answers

In order to develop a strategy that is in line with your aims, involves understanding the theories and ideas that support the practices used in your business.

What are the five different methodologies?

Five basic qualitative approach types—ethnography, story, phenomenology, grounded theory, and case study—are distinguished by a common and useful taxonomy.

Which method is most important?

Every study discipline needs a strong technique because a shaky approach will lead to shaky outcomes, which will reduce the value of your examination of the outcomes. Typically, there are many different ways you can investigate into a study topic.

To know more about methodology visit:-

brainly.com/question/29220500

#SPJ4

As part of clinical documentation improvement, a patient case review resulted in the determination that a patient's previous hospital discharge was inappropriate because the patient was transported back to the hospital via ambulance and admitted through the emergency department within three days of the previous discharge; this process is called a __________ audit.

Answers

Within three days of the previous release; this procedure is known as a readmission audit.

For an osteoporosis diagnosis, which code would be considered a medical necessity?

The WHO classifies ICD-10 code Z13. 820, Encounter for osteoporosis screening, as a medical condition that falls under the heading of "Factors influencing health status and interaction with health services."

What kind of code should be used to record a patient's disease, injury, or medical condition?

The state of the patient and the diagnosis made by the doctor are represented by ICD codes. These codes are employed in the billing procedure to establish medical necessity. Coders must ensure that the procedure they are billing for is appropriate given the provided diagnosis.

To know more about readmission audit visit :-

https://brainly.com/question/29979411

#SPJ4

A city government would like to make their streets more bike-friendly with features such as protected bike lanes. However, government officials are concerned about the effect on traffic flow. They hire a software consultant agency to develop a simulation of the traffic after the proposed changes.
What are the most likely benefits of creating a computer simulation of the proposal?
(Select two answers)
Pilihan jawaban
Once it is developed, the simulation can run at a faster speed than a real-life experiment.
The simulation can try the addition of even more bike lanes without incurring significant extra cost for each lane added.
As long as the software developers are not biased, the simulation will not include any bias for or against cyclists.
Since they are developing the simulation on a computer, it should be able to represent the proposed changes with 100% accuracy.

Answers

Once it is developed, the simulation can run at a faster speed than a real-life experiment and the simulation can try the addition of even more bike lanes without incurring significant extra cost for each lane added.

An explanation of procedural abstractions

Writing code portions, referred to as "procedures" or "static methods" in Java, that are generalized by having variable arguments is referred to as procedural abstraction. According on how its parameters are set when it is called, the concept is that we have code that can handle a range of various circumstances.

What advantages can procedural abstraction offer?

Programmers are prevented from mistakenly stealing the ideas of other programmers thanks to procedural abstraction. People can read computer programs more easily thanks to procedural abstraction. The necessity for programmers to document their code is removed by procedural abstraction.

To know more about software installation visit

brainly.com/question/5074637

#SPJ4

Other Questions
Choose the best translation:to liementirnacercaerpreferir PLS HELP FAST IM BEING TIMED!!!An airplane can seat up to 175 passengers. The airline has already sold 87 tickets for a flight on the airplane. Which graph represents the solution to the inequality that finds the number of tickets the airline can still sell?A number line going from 80 to 91. A solid circle is at 88. Everything to the left of the circle is shaded.A number line going from 80 to 91. An open circle is at 88. Everything to the left of the circle is shaded.A number line going from 80 to 91. An open circle is at 87. Everything to the right of the circle is shaded.A number line going from 80 to 91. A closed circle is at 87. Everything to the right of the circle is shaded. How big does the United Nations believe the human population will be by2100? *Mark only one oval.770 millionO 14 billion7.2 billion330 million one number exceeds another by 4 and their sum is 26.find them with proper language and process. Which of the following statements about the Texas Constitutional Convention of 1865 is not true? A. There were strong Union and secessionist factions at the convention. B. Texas had to repudiate the war debt incurred by the state. C. Texas had to return to the federal government parts of Oklahoma seized by Texas Confederate soldiers. D. The state had to formally reject the right of secession. E. Texas had to accept the abolition of slavery. What is the volume of Hannah's suitcase in cubic inches? Loss of faith in the police force will most likely result inSelect one:a. Public outcryb. The obliteration of the police forcec. Higher crime ratesd. More informants What is Dr Lanyon's reaction after he reads Dr Jekyll's letter? What appears after Grendel's mother is killed? Which of the following behavioral techniques is based on Albert Bandura's observational learning theory Did the US want Hawaii? Can someone help me start this essay?(how to kill a Mockingbird Introductory Essay)(1000-word essay on the economic, political, and racial environment in the mid 1930s American South.) State the order and type of each transformation of the graph of the function(x) = (x + 1)3 + 1 as compared to the graph of the base function The table lists recommended amounts of food to order for party guests. And are hosting a graduation party for 40 guests. They know there will also be guests stopping by who may have come from other parties. For ordering purposes, they will count each of these "drop-in" guests as half a guest. How much of each food item should and order for a graduation party with drop-in guests? what is the volume im cubic inches of the rectangular prism below 3x^2+7x=30______________ PLS HELP ME I ONLY HAV 2 MINS PLSSSSS What did Lenin argue in what is to be done? Jenny has red and white balloons. she inflates 2 red balloons for every 3 inflated white balloons. Jenny wants 20 red balloons inflated. How many total balloons will be inflated if jenny inflates the required white balloons How did the battle of antietam change the course of the american civil war?