What kind of connectors can be used to connect a PC power supply to a hard drive?

What kind of connectors can be used to connect a PC power supply to a hard drive?

• Molex
• P9
• AT
• Mini-molex 

EXPLANATION

A molex connector has cylindrical spring-metal pins that fit into cylindrical spring-metal sockets. The pins and sockets are held in a rectangular matrix in a nylon shell. The connector typically has two to 24 contacts and is polarized or keyed to ensure correct orientation. Pins and sockets can be arranged in any combination in a single housing, and each housing can be either male or female.
There are three typical pin sizes: 1.57 mm (0.062 in), 2.13 mm (0.084 in), and 2.36 mm (0.093 in). The 1.57 mm pin can carry 5 A of current, while the 2.36 mm can carry 8.5 A. Because the pins have a large contact surface area and fit tightly, these connectors are typically used for power.
https://en.wikipedia.org/wiki/Molex_connector

SOURCE

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Linux and Unix systems typically track 3 timestamps in file inodes: atime, ctime, and mtime. The "a" in atime means access. The "m" in mtime means modify. What does the "c" in ctime mean?

Linux and Unix systems typically track 3 timestamps in file inodes: atime, ctime, and mtime. The "a" in atime means access. The "m" in mtime means modify. What does the "c" in ctime mean?

• create
• cache
• change
• copy-on-write 

 

EXPLANATION

"c" in ctime means change.  Specifically, a change to the inode's status, eg, permissions, ownership, link count, file size, etc.
http://man7.org/linux/man-pages/man7/inode.7.html
"Last status change timestamp (ctime) stat.st_ctime; statx.stx_ctime"

http://www.linux-mag.com/id/8658/
"Timestamps telling when the inode itself was last change (ctime, changing time), the file content was last modified (mtime or modification time), and when the file was last accessed (atime or access time)"

SOURCE

http://man7.org/linux/man-pages/man7/inode.7.html

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In SQL, the function select datepart(dw,getdate()) returns a number representing the current day of the week. You want to use 1 for Monday, 2 for Tuesday, up to 7 for Sunday. How do you set this?

In SQL, the function select datepart(dw,getdate()) returns a number representing the current day of the week. You want to use 1 for Monday, 2 for Tuesday, up to 7 for Sunday. How do you set this?

• set datefirst 0;
• set datefirst 2;
• set datefirst 7;
• set datefirst 1; 

EXPLANATION

Datefirst says which day of the week will be treated as the start of the week and return the value 1,
When setting Datefirst, 1 means Monday will be the start of the week. The default (7) means Sunday will be the start of the week. Zero is not a valid option and does not change the current setting.
For more details, see: https://docs.microsoft.com/en-us/sql/t-sql/statements/set-datefirst-transact-sql?view=sql-server-2017

SOURCE

https://docs.microsoft.com/en-us/sql/t-sql/statements/set-datefirst-transact-sql?view=sql-server-2017

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You need to modify the GPO prefix by using IPAM. Which cmdlet should you do?

You need to modify the GPO prefix by using IPAM. Which cmdlet should you do?

• Select the Provision the IPAM server in Server Manager
• Select the Configure server discovery in Server Manager
• Run the Set-IpamConfiguration cmdlet
• Run the Invoke-IpamGpoProvisioning cmdlet 

 

EXPLANATION

The Set-IpamConfiguration cmdlet modifies the IP Address Management (IPAM) server configuration, including the TCP port over which the computer that runs the IPAM Remote Server Administration Tools
(RSAT) client connects and communicates with the computer that runs the IPAM server.

SOURCE

https://docs.microsoft.com/en-us/powershell/module/ipamserver/set-ipamconfiguration?view=win10-ps

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Which byte size unit is the largest?

Which byte size unit is the largest?

• Zettabyte
• Terabyte
• Petabyte
• Yottabyte

EXPLANATION

Yottabyte is equal to 10^24 bytes.
https://en.wikipedia.org/wiki/Yottabyte

The Byte

The byte is composed of eight bits.

• 0.1 bytes: A binary decision
• 1 byte: A single character
• 10 bytes: A single word
• 100 bytes: A telegram OR A punched card

Kilobyte (1024 Bytes)

• 1 Kilobyte: A very short story
• 2 Kilobytes: A Typewritten page
• 10 Kilobytes: An encyclopaedic page OR A deck of punched cards
• 50 Kilobytes: A compressed document image page
• 100 Kilobytes: A low-resolution photograph
• 200 Kilobytes: A box of punched cards
• 500 Kilobytes: A very heavy box of punched cards

Megabyte (1024 Kilobytes)

• 1 Megabyte: 4 books (873 pages of plain text) OR A 3.5-inch floppy disk
• 2 Megabytes: A high-resolution photograph
• 5 Megabytes: The complete works of Shakespeare OR 30 seconds of TV-quality video
• 10 Megabytes: A minute of high-fidelity sound OR A digital chest X-ray
• 20 Megabytes: A box of floppy disks
• 50 Megabytes: A digital mammogram
• 100 Megabytes: 1 meter of shelved books OR A two-volume encyclopedic book
• 200 Megabytes: A reel of 9-track tape OR An IBM 3480 cartridge tape
• 500 Megabytes: A CD-ROM OR The hard disk of a PC

Gigabyte (1,024 Megabytes, or 1,048,576 Kilobytes)

• 1 Gigabyte: A pickup truck filled with paper OR A symphony in high-fidelity sound OR A movie at TV quality. 1 Gigabyte could hold the contents of about 10 yards of books on a shelf.
• 2 Gigabytes: 20 meters of shelved books
• 5 Gigabytes: An 8mm Exabyte tape
• 20 Gigabytes: A high-quality audio collection of the works of Beethoven OR A VHS tape used for digital data
• 50 Gigabytes: A floor of books OR Hundreds of 9-track tapes
• 100 Gigabytes: A floor of academic journals OR A large ID-1 digital tapes.

Terabyte (1,024 Gigabytes)

• 1 Terabyte: An automated tape robot OR All the X-ray films in a large technological hospital OR 50,000 trees made into paper and printed.
• 1 Terabyte: 1,613 650MB CDs or 4,581,298 books.
• 1 Terabyte: 1,000 copies of the Encyclopedia Britannica.
• 2 Terabytes: An academic research library OR A cabinet full of Exabyte tapes
• 10 Terabytes: The printed collection of the US Library of Congress

Petabyte  (1,024 Terabytes, or 1,048,576 Gigabytes)

• 1 Petabyte: 5 years of Earth Observing System (EOS) (at 46 mbps)
• 1 Petabyte: 20 million 4-door filing cabinets full of text or 500 billion pages of standard printed text.
• 2 Petabytes: All US academic research libraries.
• 20 Petabytes: Production of hard-disk drives in 1995
• 200 Petabytes: All printed material ever OR Production of digital magnetic tape in 1995

Exabyte (1,024 Petabytes)

• An exabyte of data is created on the Internet each day in 2012 or 250 million DVDs worth of information.
• 5 Exabytes: All words ever spoken by human beings.

Zettabyte (1,024 Exabytes)

• Cisco estimates 1.3 zettabytes of traffic annually over the internet in 2016

Yottabyte (1,204 Zettabytes, or 1,208,925,819,614,629,174,706,176 bytes)

• It’s equal to one septillion (10²⁴) or, strictly, 2⁸⁰ bytes.
• Its name comes from the prefix ‘Yotta’ derived from the Ancient Greek οκτώ (októ), meaning “eight”, because it is equal to 1,000⁸
• In 2010, it would have cost $100 trillion to make a yottabyte storage system made out of the day’s hard drives.

After ‘Yotta’, the officially recognized prefix system comes to a halt, likely because humans haven’t had the need to work with larger quantities of… anything really. There are some other measurement units, however, which go well beyond the Yotta and which are recognized by some experts in their fields. For instance, the brontobyte is 1 followed by 27 zeros and some believe will be the scale of data enabled by the internet of things (smart devices from toasters to fridges to home sensors that constantly transmit and receive data). Gegobyte is 10 to the power 30, which by now is futile to count in DVDs or anything like it.

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What is the name of the numeric value used to identify a memory cell?

What is the name of the numeric value used to identify a memory cell?

• Boolean operation
• Hexadecimal notation
• Bit
• Address

EXPLANATION

A digital computer's memory, more specifically main memory, consists of many memory locations, each having a physical address, a code, which the CPU (or other device) can use to access it. Generally only system software, i.e. the BIOS, operating systems, and some specialized utility programs (e.g., memory testers),
address physical memory using machine code operands or processor registers, instructing the CPU to direct a hardware device, called the memory controller, to use the memory bus or system bus, or separate control, address and data busses, to execute the program's commands. The memory controllers' bus consists of a number of parallel lines, each represented by a binary digit (bit). The width of the bus, and thus the number of addressable storage units, and the number of bits in each unit, varies among computers.

SOURCE

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

 

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When called without an argument, which of the following returns the SQL Server login of the current security context.

When called without an argument, which of the following returns the SQL Server login of the current security context.

• ORIGINAL_LOGIN()
• SUSER_SNAME()
• USER_NAME()
• SUSER_SID()

EXPLANATION

SUSER_SNAME() - returns the login of the current security context.

ORIGINAL_LOGIN() - returns login of original connection context. It is not affected by context-switching.

USER_NAME() - returns the database user name of the current security context.

SUSER_SID() - Returns the Security Identifier (SID) of the current security context.

SQL Server has system-level logins and database users. While they often have the same username, they are distinct from one another. Logins are needed to gain access and set system-level permissions to SQL Server, while Users are needed for access and permissions to specific databases.

The current security context in SQL Server can be changed, known as context-switching or impersonation, with the use of the EXECUTE AS and REVERT statements in a script or batch.

Additional reading:

SQL Server Security Principals - https://docs.microsoft.com/en-us/sql/relational-databases/security/authentication-access/principals-database-engine?view=sql-server-2017

Context-switching - https://sqlity.net/en/1783/changing-security-context-execute-revert/

SOURCE

https://docs.microsoft.com/en-us/sql/t-sql/functions/security-functions-transact-sql?view=sql-server-2017

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