IT Questions and Answers :)

Friday, December 14, 2018

What command would you use to create a row in SQL?

What command would you use to create a row in SQL?

  • INSERT
  • MAKE
  • ADD
  • CREATE 

 
What command would you use to create a row in SQL?

EXPLANATION

To create a row in a SQL database, you use the command INSERT.

If we want to insert a single row in a table emp.

Query:
insert into emp values(101,’hari’);

It will add a new row has employee id 101 and employee name ‘hari’ into th emp table.

Share:

In Windows, what do you get if you change the extension of an (unprotected) Excel file from .xlsx to .zip?

In Windows, what do you get if you change the extension of an (unprotected) Excel file from .xlsx to .zip?

  • A file that MS EXCEL cannot open
  • Nothing useful at all
  • A corrupt ZIP file
  • The original spreadsheet as a set of XML files within the ZIP 

In Windows, what do you get if you change the extension of an (unprotected) Excel file from .xlsx to .zip?

EXPLANATION

Since Office 2007 Microsoft has used Open XML to store non-password protected documents.  These are then combined into a single compressed file using
the  docx, xlsx, pptx, etc. extensions.   Even though the XML files are quite large, they compress very well.
Share:

Thursday, December 13, 2018

Which of the following is a security advantage of using NoSQL vs. SQL databases in a three-tier environment?

Which of the following is a security advantage of using NoSQL vs. SQL databases in a three-tier environment?

  • NoSQL databases are not vulnerable to SQL injection attacks.
  • NoSQL databases perform faster than SQL databases on the same hardware.
  • NoSQL databases encrypt sensitive information by default.
  • NoSQL databases are not vulnerable to XSRF attacks from the application server 

 
Which of the following is a security advantage of using NoSQL vs. SQL databases in a three-tier environment?

EXPLANATION

A NoSQL (originally referring to "non SQL" or "non relational")[1] database provides a mechanism for storage and retrieval 
of data that is modeled in means other than the tabular relations used in relational databases. Such databases have existed since the late 1960s, but did not obtain the "NoSQL" moniker until a surge of popularity in the early twenty-first century,[2] triggered by the needs of Web 2.0 companies such as Facebook, Google, and Amazon.com.[3][4][5] NoSQL databases are increasingly used in big data and real-time webapplications.[6] NoSQL systems are also sometimes called "Not only SQL" to emphasize that they may support SQL-like query languages.

SOURCE

https://en.wikipedia.org/wiki/NoSQL

Author Orginally copied from

http://webcache.googleusercontent.com/search?q=cache:KiyrP91akesJ:https://www.briefmenow.org/comptia/sql-databases-in-a-three-tier-environment-3/&hl=en&gl=us&strip=1&vwsrc=0



Share:

Thursday, December 6, 2018

What does the Transact-SQL server RAND function do?

What does the Transact-SQL server RAND function do?

  • Aggregates a subset of random numbers
  • Generate a random number
  • Requests a range of numbers from a subset
  • Selects an random number from subset 

 
What does the Transact-SQL server RAND function do?

EXPLANATION




 SQL Server: RAND Function
This SQL Server tutorial explains how to use the RAND function in SQL Server (Transact-SQL) with syntax and examples.

Description

In SQL Server (Transact-SQL), the RAND function can be used to return a random number or a random number within a range.

Syntax

The syntax for the RAND function in SQL Server (Transact-SQL) is:
RAND( [seed] )

Parameters or Arguments

seed
Optional. If specified, it will produce a repeatable sequence of random numbers each time that seed value is provided.

Note

  • The RAND function will return a value between 0 and 1 (not inclusive), so value > 0 and value < 1.
  • The RAND function will return a completely random number if no seed is provided.
  • The RAND function will return a repeatable sequence of random numbers each time a particular seed value is used.

Random Decimal Range

To create a random decimal number between two values (range), you can use the following formula:
SELECT RAND()*(b-a)+a;
Where a is the smallest number and b is the largest number that you want to generate a random number for.

SELECT RAND()*(25-10)+10;
The formula above would generate a random decimal number between 10 and 25, not inclusive.
TIP: This formula would generate a random decimal number that is > 10 and < 25 but it would never return exactly 10 or 25.

Random Integer Range

To create a random integer number between two values (range), you can use the following formula:
SELECT FLOOR(RAND()*(b-a+1))+a;
Where a is the smallest number and b is the largest number that you want to generate a random number for.
SELECT FLOOR(RAND()*(25-10+1))+10;
The formula above would generate a random integer number between 10 and 25, inclusive.
TIP: This formula would generate a random integer number that is >= 10 and <= 25.

Applies To

The RAND function can be used in the following versions of SQL Server (Transact-SQL):
  • SQL Server 2017, SQL Server 2016, SQL Server 2014, SQL Server 2012, SQL Server 2008 R2, SQL Server 2008, SQL Server 2005

Example of Random Number

Let's explore how to use the RAND function in SQL Server (Transact-SQL) to generate a random number between 0 and 1, not inclusive.
For example:
SELECT RAND();
Result:  0.143811355073783     (no seed value, so your answer will vary)

SELECT RAND(9);
Result:  0.713741056982989     (with seed value of 9)

SELECT RAND(-5);
Result:  0.713666525097956     (with seed value of -5)

Example of Random Decimal Range

Let's explore how to use the RAND function in SQL Server (Transact-SQL) to generate a random decimal number between two numbers (ie: range).
For example, the following would generate a random decimal value between 1 and 10, not inclusive (random number would be greater than 1 and less than 10):
SELECT RAND()*(10-1)+1;
Result:  5.09104269717813      (no seed value, so your answer will vary)

SELECT RAND(9)*(10-1)+1;
Result:  7.4236695128469       (with seed value of 9)

SELECT RAND(-5)*(10-1)+1;
Result:  7.42299872588161      (with seed value of -5)

Example of Random Integer Range

Let's explore how to use the RAND function in SQL Server (Transact-SQL) to generate a random integer number between two numbers (ie: range).
For example, the following would generate a random integer value between 10 and 20, inclusive:
SELECT FLOOR(RAND()*(20-10+1))+10;
Result:  19                   (no seed value, so your answer will vary)

SELECT FLOOR(RAND(9)*(20-10+1))+10;
Result:  17                   (with seed value of 9)

SELECT FLOOR(RAND(123456)*(20-10+1))+10;
Result:  10                   (with seed value of 123456)
 
Share:

Tuesday, December 4, 2018

What is the largest partition size supported by native DOS running FAT16?

What is the largest partition size supported by native DOS running FAT16?

  • 3GB
  • 2GB
  • 1GB
  • 512MB 
What is the largest partition size supported by native DOS running FAT16?

EXPLANATION

Due to the mathematical limitations of FAT16, without an overlay file or special driver the largest partition size is 2GB.The limit on partition size was dictated by the 8-bit signed count of
sectors per cluster, which originally had a maximum power-of-two value of 64. With the standard hard disk sector size of 512 bytes, this gives a maximum of 32 KiB cluster size, thereby fixing the "definitive" limit for the FAT16 partition size at 2 GiB for sector size 512.

SOURCE

https://en.wikipedia.org/wiki/File_Allocation_Table

Share:

Wednesday, November 28, 2018

What is the not equals operator in Excel?

What is the not equals operator in Excel?

  • NOT()
  • <>
  • >=
  • !=

 
What is the not equals operator in Excel?

EXPLANATION

When comparing two pieces of data in Excel, what operator would you use to test if they were not equal?
If I were comparing cells A1 to B1, my formula would be:

=A1___B1
NOT() is a function, not an operator.

SOURCE

https://support.office.com/en-us/article/Calculation-operators-and-precedence-in-Excel-48be406d-4975-4d31-b2b8-7af9e0e2878a#tblID0EABCAFAAA
Share:

Monday, November 26, 2018

In SQL, what is the effect of the TRUNCATE TABLE statement?

In SQL, what is the effect of the TRUNCATE TABLE statement?

  • To delete all of the rows contained within a table
  • To drop all of the tables in a database
  • To shorten all textual values in a column to a specified number of characters
  • To drop all of the columns defined on a table 

 
In SQL, what is the effect of the TRUNCATE TABLE statement?

EXPLANATION

TRUNCATE TABLE table-name;
 
TRUNCATE removes all of the rows from the specified table without logging the individual row deletions, without scanning the table, and makes freed disk space available to the operating system immediately, without requiring a subsequent VACUUM operation.
TRUNCATE TABLE is similar to a DELETE statement with no WHERE clause, which also removes all of the rows from a table; however, TRUNCATE is faster and uses fewer resources. TRUNCATE is most useful when working with very large tables where an unqualified DELETE could adversely affect database performance.

Share:

Tuesday, November 20, 2018

Which of these is an advantage of Manchester Encoding?

Which of these is an advantage of Manchester Encoding?

  • It uses less bits than the original signal
  • It is named after an English City
  • Very easy to understand
  • The signal is self-synchronizing 

Which of these is an advantage of Manchester Encoding?

EXPLANATION

"In data transmission, Manchester encoding is a form of digital encoding in which data bits are represented by transitions from one logical state to the other. This is different from the more common method of encoding, in which a bit is represented by either a high state such as +5 volts or a low state such as 0 volts".
"The chief advantage of Manchester Encoding is the fact that the signal synchronizes itself." (See link for further reading).

http://searchnetworking.techtarget.com/definition/Manchester-encoding
Share:

Tuesday, November 13, 2018

Which of these files will not fit in a 32GB flashdrive formatted as FAT32?

Which of these files will not fit in a 32GB flashdrive formatted as FAT32?

  • 10 .msi files with 1000MB each
  • A .zip file with 1024MB
  • 3 .tar.gz files with 5GB each
  • All of them would fit just fine 
Which of these files will not fit in a 32GB flashdrive formatted as FAT32?

EXPLANATION

Since your flash drive is formatted with the FAT32 file system, any file that is larger than 4GB will not be placed there. This type of a file system has a built-in limitation on the size of the files that it may contain. Although the total size of the files that you can copy to a FAT32 drive could be as large as 2TB (or the physical capacity of the drive, whichever is smaller), the size of each individual file may not exceed 4GB.

This limitation may sound silly: why would anyone design a system that would not allow for the larger files? The problem is, when the FAT32 file system was designed (that was back in the days of Windows 95), no one anticipated that we would have such large files in use today. Or, maybe the designers hoped that by the time such large files became common, the use of the FAT32 system would be replaced by more modern systems.

Share:

Which of the following is not an example of a denial-of-service attack?

Which of the following is not an example of a denial-of-service attack?

  • Fraggle
  • Smurf
  • Teardrop
  • Roadrunner 

Which of the following is not an example of a denial-of-service attack?

EXPLANATION

 Smurf / Smurfing

When conducting a smurf attack, attackers will use spoof their IP address to be the same as the victim’s IP address. This will cause great confusion on the victim’s network, and a massive flood of traffic will be sent to the victim’s networking device, if done correctly.

Most firewalls protect against smurf attacks, but if you do notice one, there are several things you can do. If you have access to the router your network or website is on, simply tell it to not forward packets to broadcast addresses. In a Cisco router, simply use the command: no ip directed-broadcast.

This won’t necessarily nullify the smurf attack, but it will greatly reduce the impact and also prevent your network or website from attacking others by passing on the attack. Optionally, you could upgrade your router to newer Cisco routers, which automatically filter out the spoofed IP addresses that smurf attacks rely on.

Fraggle


A Fraggle attack is exactly the same as a smurf attack, except that it uses the user datagram protocol, or UDP, rather than the more common transmission control protocol, or TCP. Fraggle attacks, like smurf attacks, are starting to become outdated and are commonly stopped by most firewalls or routers.

If indeed you think you are being plagued by a fraggle attack, simply block the echo port, located at port 7. You may also wish to block port 19, which is another commonly used fraggle exploitable port. This attack is generally less powerful than the smurf attack, since the TCP protocol is much more widely used than the UDP protocol.

Teardrop


In the teardrop attack, packet fragments are sent in a jumbled and confused order. When the receiving device attempts to reassemble them, it obviously won’t know how to handle the request. Older versions of operating systems will simply just crash when this occurs.

Operating systems such as Windows NT, Windows 95, and even Linux versions prior to version 2.1.63 are vulnerable to the teardrop attack. As stated earlier, upgrading your network hardware and software is the best way to stay secure from these types of attacks.
Fraggle, Smurf, and Teardrop are all actual denial-of-service attacks. Roadrunner is not.
Share:

Wednesday, November 7, 2018

Which of the following is the main purpose of a parked CPU core?

Which of the following is the main purpose of a parked CPU core?

  • Saves Power
  • Increase performance of applications
  • Reserves CPU core for specific application process
  • To prolong the lifespan of the CPU 
 Which of the following is the main purpose of a parked CPU core?

EXPLANATION

This process essentially puts your CPU cores in a sleep state, and wakes them up when an application depends on higher core usage. Majority of the time this is left enabled unless your a power user or a gamer. It can increase performance slightly for those situations. On some processors, this option cannot be disabled.


SOURCE

https://ttcshelbyville.wordpress.com/2013/12/29/what-is-core-parking-and-should-you-adjust-it/

Share:

Tuesday, November 6, 2018

In Vmware, what file extension does the disk descriptor file use?

In Vmware, what file extension does the disk descriptor file use?

  • .vmtm
  • .vmx
  • .vmdk
  • .vmdf 

EXPLANATION

The correct answer is .VMDK.
Two files can have this extension, the disk descriptor file and the flat vmdk file.
Source : https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&external...
Source : http://cdn.ttgtmedia.com/digitalguide/images/Misc/anatomy_avm_4.jpg
Share:

What do you call the feature in packet-based data transmission protocols (Like TCP) that governs the amount of data (number of packets) the receiver is able to accept from the sender?

What do you call the feature in packet-based data transmission protocols (Like TCP) that governs the amount of data (number of packets) the receiver is able to accept from the sender?

  • Sequence Number
  • Jitter
  • CiDR
  • Sliding Window 

What do you call the feature in packet-based data transmission protocols (Like TCP) that governs the amount of data (number of packets) the receiver is able to accept from the sender?

EXPLANATION

The sliding window feature informs the sender how much data (packets) the receiver can accept.  Since networks are dynamic and are prone to congestion this number fluctuates depending on a number of variables.  Essentially if my PC is sending a file to the server it may send 10 packets out of 20,000 to start the transfer.  If the server was able to receive all of those packets it may request more.
 This will continue until the server either can't accept more because its buffer is full or some packets were missed because of congestion.  The sender will then retransmit missed packets and begin to scale down the window until the server and the receiver are in sync.  This back and forth continues to the end of the transfer.
https://www.google.com/search?num=50&q=sliding+window+protocol&oq=Sliding+Window+pr&gs_l...
Share:

What is cgroups in modern Linux kernels?

What is cgroups in modern Linux kernels?

  • A set of tools for paravirtualization
  • A feature that isolates and limits resource usage of processes
  • A friendly IPtables manager written in C
  • A collection of tools that prevents malware using mandatory access controls policies 

 
What is cgroups in modern Linux kernels?

EXPLANATION

Cgroups (abbreviated from control groups) is a Linux kernel feature that limits, accounts for, and isolates the resource usage (CPU, memory, disk I/O, network, etc.) of a collection of processes.
If you are using Docker give it a try! This may be useful for hungry Java apps ;)
See more at Wikipedia and kernel.org


Share:

What is the default TCP port used by Microsoft SQL server?

What is the default TCP port used by Microsoft SQL server?

  • 1433
  • 3389
  • 1723
  • 987

What is the default TCP port used by Microsoft SQL server?

EXPLANATION

The default (and IANA official port) for Microsoft SQL Server is TCP 1433.
Port 3389 is the default port for Microsoft RDP.
Port 1723 is the default port for PPTP VPN.
Port 987 is used by the Companyweb sharepoint site on Microsoft Small Business Server 2008 and later.

SOURCE

https://msdn.microsoft.com/en-us/library/cc646023.aspx
Share:

Thursday, October 25, 2018

You can use which of the following to inject massive amounts of random data into a program or protocol stack for bug detection?

You can use which of the following to inject massive amounts of random data into a program or protocol stack for bug detection?

  • Cross-site scripting
  • Fuzzing
  • Cross-site request forgery
  • Input validation 

You can use which of the following to inject massive amounts of random data into a program or protocol stack for bug detection?

EXPLANATION

You can use fuzzing to inject semi-random data into a program or protocol stack in order to detect bugs.

Fuzz testing or Fuzzing is a Black Box software testing technique, which basically consists in finding implementation bugs using malformed/semi-malformed data injection in an automated fashion.

Fuzz testing was developed at the University of Wisconsin Madison in 1989 by Professor Barton Miller and his students. Their (continued) work can be found at http://www.cs.wisc.edu/~bart/fuzz/ ; it's mainly oriented towards command-line and UI fuzzing, and shows that modern operating systems are vulnerable to even simple fuzzing.


Share:

Tuesday, October 23, 2018

What are VM snapshots intended to be used for?

What are VM snapshots intended to be used for?

  • To shut down the server
  • As a backup tool for your VMs
  • To create albums
  • To easily revert the VM to an earlier state 

What are VM snapshots intended to be used for?

EXPLANATION

Snapshots provide a fast and easy way to revert the virtual machine to a previous state. For this reason, virtual machine snapshots are intended mainly for use in development and test environments. Having an easy way to revert a virtual machine can be very useful if you need to recreate a specific state or condition so that you can troubleshoot a problem.
There are certain circumstances in which it may make sense to use snapshots in a production environment. For example, you can use snapshots to provide a way to revert a potentially risky operation in a production environment, such as applying an update to the software running in the virtual machine.
Many backup products use snapshots in a production environment. They create a snapshot and then processing continues from the snapshot, meanwhile they have an unchanging original to back up. Once the backup is completed the snapshot is merged back into the live environment. This allows a machine to be backed up with very little affect for the users and for them remains up 24/7.
NB: Hyper-V snapshots do not replace backups. Backup usually involves some form of duplication (so two copies of the protected data exist) but in snapshots... there is no duplication whatsoever. All data is in VHD(X) file and changes in AVHD(X) file and if the VHD(X) file is damaged/lost, the data is pretty much gone. Also with most backups you can restore a single file to an earlier state, but with Snapshots, it's all or nothing (meaning if an user wants a file from last week, you'd have to bring the whole system back a week). There are other concerns as well (there might be performance  issues with multiple snapshots, snapshots usually lose value as they age and there are issues with disk space)

SOURCE

https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1015180
Share:

Monday, October 22, 2018

If Windows cannot find an active DHCP server, which network does it use by default for the network port?

If Windows cannot find an active DHCP server, which network does it use by default for the network port?

  • 192.168.0.0/16
  • 169.254.0.0/16
  • 172.16.0.0/12
  • 127.0.0.1/32 

 
If Windows cannot find an active DHCP server, which network does it use by default for the network port?

EXPLANATION

The 169.254.0.0/16 network is used for Automatic Private IP Addressing, or APIPA. If a DHCP client attempts to get an address, but fails to find a DHCP server after the timeout and retries period it will randomly assume an address from this network. This is defined in RFC 3927.
192.168.0.0/16 and 172.16.0.0/12 are defined for private use networks (LANs). It has to be configured by manual installation as a static IP or by a DHCP Server.
127.0.0.1/32 is the loopback address of the PC. The loopback address can be used to test the performance of TCP/IP by pinging 127.0.0.1. Upon receiving a response, you can assume that the software associated with the protocol is fine.

Share:

Friday, October 19, 2018

In Microsoft SQL Server, why does SELECT 1/2 return 0?

In Microsoft SQL Server, why does SELECT 1/2 return 0?

  • Numerator and denominator are both integers, so the result will be an integer
  • It doesn't - it returns 0.5
  • A bug in the code performing the division
  • A bug in the display in SSMS 

 
In Microsoft SQL Server, why does SELECT 1/2 return 0?

EXPLANATION

Due to the data type of the numerator and denominator being an "int", the return type is also assigned as an integer. While internally, the engine performs the calculation as 0.5, because the data type is an integer, the value gets converted to 0 and is returned as such.
Another way to say this is that the mathematical answer is 0.5 but because the system is only able to return an integer (whole number) the answer becomes 0 (the "whole number" in the answer).

Share:

Wednesday, October 17, 2018

Which of the following Windows console commands deletes a folder (c:\test), whether or not it is empty, without issuing any warnings?

Which of the following Windows console commands deletes a folder (c:\test), whether or not it is empty, without issuing any warnings?

  • rd test
  • rd test\* /q
  • del c:\test\*.* /s
  • rd c:\test /s /q 

Which of the following Windows console commands deletes a folder (c:\test), whether or not it is empty, without issuing any warnings?

EXPLANATION

The /s switch deletes ALL elements recursively inside the specified folder.
The /q switch is the silent mode, meaning there will be absolutely no warnings.
Caution

When you run rd /s in quiet mode, the entire directory tree is deleted without confirmation. Ensure that important files are moved or backed up before using the /q command-line option.
 
Share:

Thursday, October 11, 2018

What is the maximum number of devices that you can connect to a single USB 2.x controller?

What is the maximum number of devices that you can connect to a single USB 2.x controller?

  • 255
  • 31
  • 63
  • 127

What is the maximum number of devices that you can connect to a single USB 2.x controller?

EXPLANATION

Technically, a USB network is capable of supporting 128 nodes, though the USB controller itself is also a node.
In addition, any USB hubs, self-powered or bus-powered, count as additional nodes and reduce the number of nodes you can connect to the controller.
https://en.wikipedia.org/wiki/USB_hub#Physical_layout
 
Share:

Which of the following is NOT a daemon in Postfix?

Which of the following is NOT a daemon in Postfix?

  • qmgr
  • master
  •  crond
  • smtpd 

 
Which of the following is NOT a daemon in Postfix?

EXPLANATION

The crond daemon is a Linux daemon, not a Postfix daemon.
The master daemon is the brain of the Postfix mail system. It spawns all other daemons. The smtpd daemon (server) handles incoming connections. The qmgr daemon is the heart of the Postfix mail system. It processes and controls all messages in the mail queues.


Share:

Friday, September 28, 2018

At a Windows command prompt that is set to the root of the drive, which of the following commands will search the entire drive for all occurrences of the "Testing.docx" file?

At a Windows command prompt that is set to the root of the drive, which of the following commands will search the entire drive for all occurrences of the "Testing.docx" file?

  • DIR /ALL Testing.docx
  • DIR Testing.docx
  • DIR /S Testing.docx
  • DIR /R Testing.docx 

 
At a Windows command prompt that is set to the root of the drive, which of the following commands will search the entire drive for all occurrences of the "Testing.docx" file?

EXPLANATION

The directory command allows many flags, including the recursive search flag "/S".
This flag searches the current folder and all sub folders.
Share:

Thursday, September 27, 2018

What IEEE standard was Wired Equivalent Privacy first introduced?

What IEEE standard was Wired Equivalent Privacy first introduced?

  • 802.1x
  • 801.1a
  • 802
  • 802.11 


EXPLANATION

IEEE introduced WEP in the 802.11 standard but updated it in the 802.1x.

SOURCE

https://www.giac.org/paper/gsec/4214/wireless-security-ieee-80211-standards/106760
Share:

Wednesday, September 26, 2018

An initialization vector should be which of the following?

An initialization vector should be which of the following?

  • Repeatable and random
  • Unique and predictable
  • Unique and unpredicatable
  • Repeatable and unique 

 
An initialization vector should be which of the following?

EXPLANATION

An initialization vector (IV) should be unique and unpredictable. To prevent an attack,
an IV must not be repeated with a given key and should appear random.

SOURCE

https://en.wikipedia.org/wiki/Initialization_vector
Share:

Tuesday, September 25, 2018

Which type of RAID configuration requires minimum six drives?

Which type of RAID configuration requires minimum six drives?

  • RAID 50 (RAID 5 + 0)
  • RAID 100 (RAID 10+0)
  • RAID 6
  • RAID 60 (RAID 6 + 0) 

 
Which type of RAID configuration requires minimum six drives?

EXPLANATION

RAID 50, also called RAID 5+0, combines the straight block-level striping of RAID 0 with the distributed parity of RAID 5.[3] As a RAID 0 array striped across RAID 5 elements, minimal RAID 50 configuration requires six drives.

SOURCE

https://en.wikipedia.org/wiki/Nested_RAID_levels
Share:

In sql, which of the following is applicable to the CHAR datatype?

In sql, which of the following is applicable to the CHAR datatype?

  • CHAR stores alphanumeric characters of fixed size
  • Stores alphanumeric characters of variable length
  • to create scripts containing infinite characters
  • Type as many characters as you want 

 
In sql, which of the following is applicable to the CHAR datatype?

EXPLANATION

The only difference between CHAR and VARCHAR2 is that CHAR stores fixed-length alphanumeric characters, between 1 and 2000 bytes or characters. If you are stored in the JUNIOR surname in a CHAR (50) column, a column will contain a JUNIOR string + 44 whitespaces that are automatically added to the total column volume.

SOURCE

http://www.fabioprado.net/2011/08/qual-tipo-de-dado-devo-usar-char.html

Share:

Which of the following is NOT a computer programming language?

Which of the following is NOT a computer programming language?

  • Lisp
  • Occam
  • SNOBOL
  • Modal


EXPLANATION

MODAL isn't a programming language but is used in computer applications, especially within websites. It is a graphical window control element, subordinate to an application's main window.
SNOBOL (StriNg Oriented and symBOlic Language), is a text-string-oriented language developed by AT&T Bell Labs in the 1960s.
LISP, developed in the 1950s, is one of the oldest high-level programming languages and is only pre-dated by the likes of FORTRAN.
OCCAM was one of the earliest Concurrent programming languages, developed by INMOS as the native programming language for their Transputer Microprocessors.

SOURCE

https://en.wikipedia.org/wiki/List_of_programming_languages
 
Share:

Friday, September 21, 2018

Access management is most affected by which of these aspects of cloud computing?

Access management is most affected by which of these aspects of cloud computing?

  • Internet Service Provider
  • Virtualization
  • Federated Identity
  • Cloud backup 

 
Access management is most affected by which of these aspects of cloud computing?

EXPLANATION

Federated Identity allows you to use a central identity store both inside and outside of your organization. Cloud backup and Internet Service Provider have to do with IT service continuity management, not access management. Virtualization affects all IT processes, but not as much as identity federation.
Share:

Tuesday, September 18, 2018

Which of the following events would you NOT expect to see in the Windows security log?

Which of the following events would you NOT expect to see in the Windows security log?

  • Successful login attempts
  • User account deleted
  • Hardware driver failures
  • Shutdown events 

 
Which of the following events would you NOT expect to see in the Windows security log?

EXPLANATION

All of the above events will be logged in the Windows event log, however there are several different types of log that each contain relevant information.
Application log - contains logging information of events generated by applications.
Security log - contains information related to logon attempts, password changes, group membership, etc.
System log - contains information related to Windows system components, such as driver failures. These logs are predetermined by Windows.
Setup log - contains events related to application setup
ForwardedEvents log - used to store events collected from remote computers

The above alerts appear in the Windows security log as:
Event ID 4624 -  An account was successfully logged on
Event ID 4609 - Windows is shutting down
Event ID 4726 - User account was deleted
Hardware driver failures will appear in the system log




SOURCE

https://technet.microsoft.com/en-us/library/cc722404(v=ws.11).aspx
Share:

Monday, September 17, 2018

Which layer of the OSI model does a packet exist on?

Which layer of the OSI model does a packet exist on?

  • 3
  • 1
  • 2
Which layer of the OSI model does a packet exist on?

 

EXPLANATION

Packets exist on the third, or Network, layer of the OSI model. The following are the counterparts for packets on the other layers: Layer 1 (Physical): bits; Layer 2 (Data Link): frames; Layer 4 (Transport): segments.

SOURCE

https://en.wikipedia.org/wiki/OSI_model#Description_of_OSI_layers
Share:

Friday, September 14, 2018

To send someone a secure e-mail message using PGP, you should use which of the following?

To send someone a secure e-mail message using PGP, you should use which of the following?

  • The recipient's private key
  • Your public key
  • Your private key
  • The recipient's public key 

To send someone a secure e-mail message using PGP, you should use which of the following?

EXPLANATION

Pretty good privacy (PGP) can be used to send messages confidentially. For this, PGP combines symmetric-key encryption and public-key encryption. The message is encrypted using a symmetric
encryption algorithm, which requires a symmetric key. Each symmetric key is used only once and is also called a session key. The message and its session key are sent to the receiver. The session key must be sent to the receiver so they know how to decrypt the message, but to protect it during transmission, it is encrypted with the receiver's public key. Only the private key belonging to the receiver can decrypt the session key.
https://en.wikipedia.org/wiki/Pretty_Good_Privacy
Share:

Wednesday, September 12, 2018

In SQL, which of the following is the generally preferred way to handle the case where a transaction in progress terminates abnormally?

In SQL, which of the following is the generally preferred way to handle the case where a transaction in progress terminates abnormally?

  • Rollforward
  • Rollback
  • Switch to duplicate database
  • Reprocess transactions 

 
In SQL, which of the following is the generally preferred way to handle the case where a transaction in progress terminates abnormally?

EXPLANATION

A transaction is a logical unit of work that contains one or more SQL statements. A transaction is an atomic unit. The effects of all the SQL statements in a transaction can be either all committed (which means that they applied to the database) or all 
rolled back (undone from the database). So, if a transaction terminates abnormally, perform a rollback.

Share:

Tuesday, September 11, 2018

What VMware vSphere feature allows guest VMs to restart on another host in the event that their host fails?

What VMware vSphere feature allows guest VMs to restart on another host in the event that their host fails?

  • DRS
  • High availability
  • Storage DRS
  • Fault tolerance 

 
What VMware vSphere feature allows guest VMs to restart on another host in the event that their host fails?

EXPLANATION

VMware's High Availability (known to us lazy people as HA) allows guest VMs to restart on another host in the event of host failure. For example, if you have two hosts, both with VMs, and the first host has a hardware failure and becomes unresponsive, the VMs that were running on the failed host restart on the other host (provided it has the capacity to run them).
Read more here: https://www.vmware.com/products/vsphere/features/high-availability

Share:

Thursday, September 6, 2018

Which of the following is NOT a Linux distro?

Which of the following is NOT a Linux distro?

  • BSD
  • Ubuntu
  • Mint
  • Red Hat 

Which of the following is NOT a Linux distro?

EXPLANATION

Berkeley Software Distribution (BSD) is a Unix operating system derivative developed and distributed by the Computer Systems Research Group 
(CSRG) of the University of California, Berkeley, from 1977 to 1995. Today the term "BSD" is often used non-specifically to refer to any of the BSD descendants which together form a branch of the family ofUnix-like operating systems. Operating systems derived from the original BSD code remain actively developed and widely used.
Share:

Wednesday, September 5, 2018

By default, what is the lowest permission needed to join computers to an Active Directory domain?

By default, what is the lowest permission needed to join computers to an Active Directory domain?

  • Schema Admin
  • Domain Admins
  • Authenticated Users
  • Enterprise Admins 

 

EXPLANATION

By default any Authenticated User can add up to 10 computers to a domain.  The risk with this could be that a user sets up a new workstation and give themselves an admin account on the computer, then add it to the domain using their domain account. 
With these elevated permissions they could do many things.  Most notably, but not limited to, the higher chance of getting a virus on the system to an inexperienced user.

SOURCE

https://technet.microsoft.com/en-us/library/cc976452.aspx
Share:

Tuesday, September 4, 2018

In Unix systems, what are semaphores?

In Unix systems, what are semaphores?

  • A technique for pipeline deletion inside processes
  • A technique for coordinating or synchronizing activities
  • A technique for pipeline creation inside threads
  • A technique for Traffic lights management inside an operating system 

 
In Unix systems, what are semaphores?

EXPLANATION

In programming, especially in Unix systems, semaphores are a technique for coordinating or synchronizing activities in which multiple processes compete for the same operating system resources.
A semaphore is a value in a designated place in operating system (or kernel) storage that each process can check and then change. Depending on the value that is found, the process can use the resource or will find that it is already in use and must wait for some period before trying again. Semaphores can be binary (0 or 1) or can have additional values. Typically, a process using semaphores checks the value and then, if it using the resource, changes the value to reflect this so that subsequent semaphore users will know to wait.
Semaphores are commonly use for two purposes: to share a common memory space and to share access to files. Semaphores are one of the techniques for interprocess communication (IPC). The C programming language provides a set of interfaces or "functions" for managing semaphores.

SOURCE

https://whatis.techtarget.com/definition/semaphore
Share:

Monday, September 3, 2018

With regards to DNS, what is the difference between an A record and an AAAA record?

With regards to DNS, what is the difference between an A record and an AAAA record?

  • A record holds one IP for one host and AAAA record can hold up to four IPs for one host
  • A record replies to one ping and AAAA record replies to four pings.
  • A record is for the A-team and AAAA record is for a squad of A-teams.
  • A record holds the IPv4 address and AAAA record holds the IPv6 address 

With regards to DNS, what is the difference between an A record and an AAAA record?

EXPLANATION

An A and AAAA record are both primary DNS records.  They associate a host name with a specific IP address, so that when a user types in a web address, their browser knows where to go for the actual website. An A record holds the IPv4 address and an AAAA record holds the IPv6 address.
More info here - https://en.wikipedia.org/wiki/List_of_DNS_record_types
Share:

Friday, August 31, 2018

What of the following names is a USB device that registers itself as a network adapter but is a covert systems administration and penetration testing tool?

What of the following names is a USB device that registers itself as a network adapter but is a covert systems administration and penetration testing tool?

  • NET Ninja
  • BeamGun
  • Rubber Ducky
  • LAN Turtle 

What of the following names is a USB device that registers itself as a network adapter but is a covert systems administration and penetration testing tool?

EXPLANATION

The LAN Turtle is a covert Systems Administration and Penetration Testing tool providing stealth remote access, network intelligence gathering, and man-in-the-middle monitoring capabilities.
Housed within a generic "USB Ethernet Adapter" case, the LAN Turtle’s covert appearance allows it to blend into many IT environments.
See: https://lanturtle.com/ for more information
Share:

Thursday, August 30, 2018

You only want to use on-premises servers to authenticate. You would like to allow access to cloud email accounts through a user's local credentials. Which solution should you use?

You only want to use on-premises servers to authenticate. You would like to allow access to cloud email accounts through a user's local credentials. Which solution should you use?

  • Implement SaaS
  • Recreate user accounts in the cloud
  • Replicate local user accounts to the cloud
  • Identity federation 

You only want to use on-premises servers to authenticate. You would like to allow access to cloud email accounts through a user's local credentials. Which solution should you use?

EXPLANATION

Identity federation uses a single identity provider to authorize user access to multiple software applications, including cloud email.
Replicating user accounts means you are NOT using the on-premises user identities as you require. SaaS provides end-user software services over the network and has nothing to do with authorization. Recreating user accounts in the cloud won't work because we need to use local user accounts for authentication.
Share:

Popular Posts

Blog Archive