What is GUID?

A “Globally Unique Identifier” is known as a GUID. A GUID is a “Globally Unique ID” also called a UUID (Universally Unique ID). Anytime you need an identity that is sure to stand out from the crowd, you can use it. Let’s discuss this briefly about GUI.

What is GUID?

An identification (ID) is represented by a 128-bit text string called a GUID (globally unique identifier). When a distinct reference number is required to identify data on a computer or network, organizations create GUIDs. Hardware, software, accounts, documents, and other objects can all be uniquely identified by a GUID. The phrase is frequently used in Microsoft applications as well.

When a unique identification with an extremely low probability of being duplicated is required, GUIDs come in handy. All computers and networks can use the text string. Similar to serial numbers, GUIDs are used by companies to make sure that database records are not duplicated and that each piece of data has a unique ID that can be found in all databases.

Microsoft first created the term “GUID” to describe a particular version of the term “Universally Unique Identifier,” or UUID. Since then, the names have been combined, and they are now used equally in the RFC 4122 definition. The RFC 4122 specification is followed by many GUID variants.

Purpose of GUID

GUIDs act as global identifiers, providing a simple and reliable identifying system. They can be generated locally using roll numbers, symbols, or admission numbers. For example, in a class of 60 students, roll number 5 may be used as a unique identifier. At higher levels, a symbolic alphabet can be included in the roll number. But this can only be handled locally. Unique IDs are required on both local and global scales to chart another school globally.

For example, admission numbers can be used to check each student’s map. However, this technique is limited to local management. The book says that GUIDs are unnecessary for schools because their databases are often local. However, they are employed when a database has a global impact, such as when many independent systems or global customers generate unique IDs and map their data. This offers more advantages than Global Unique Identifiers, which are used to generate unique data.

How Unique is GUID?

If 1,0000,000,000 GUIDs per second were generated for a year, the generation algorithm‘s uniqueness and 128-bit size would make sure that the probability of a duplication would be only 50%. If every person on earth produced 600,000,000 GUIDs, the chance of a duplicate would be reduced to 50%.

When Use GUIDs?

Let’s suppose we have five client apps that produce, process, and insert transactional data into a database table. This table has a primary key, and we need to guarantee that the keys are unique. We use GUID to make sure that the table’s primary key is unique. Instead of requesting a unique ID from a central authority or depending on a database, each client can generate one on its own.

Alternatively, if security requirements need an independent central body to generate IDs in line with established information security standards such as ISO27001, we will install a GUID generator on our server. When a client program requires a GUID, it will ask the server for one.

In order to guarantee that every one of our independent systems or clients creates or receives a distinct ID with every request it makes to the central server, we employ GUID. GUID also helps the server in identifying between any two calls for the same service made by the same client.

GUID Versions

There are five different GUID versions, the majority of which follow to the RFC 4122 criteria.

• Date/time and MAC address: This version creates IDs using the current time and client’s MAC.
• Controlling the Distributed Computing Environment: This version is similar to the Date-time and MAC address GUID formats, except that the first four bytes of the timestamp are replaced with the user’s Portable Operating System Interface UID. It was defined in the early 1990s and is now rarely used. This version is also not specified in RFC4122.
• Message-digest algorithm (MD5) hash, namespace: This version produces IDs using an MD5 hash and a namespace that has been translated to hex. GUIDs created by the same namespace are comparable in this format.
• Randomly produced numbers: This version is built using random bits, with the exception of 6 bits for the version and variation bits. There is no specification for how the random digits should be created, therefore pseudo-random generators can be used.
• Secure Hash Algorithm 1 (SHA-1) hash and namespace: This version looks similar to the MD5 hash and namespace, save instead of MD5, it hashes using SHA-1.

Advantages of GUID

• Globally Individuality: GUIDs are meant to be universally unique over all systems, networks, and time periods. This makes sure that no two entities share the same identification, lowering the possibility of issues or duplication in separated systems.
• Compatibility: GUIDs are platform-independent and can be used in a number of operating systems, computer languages, and databases without change. This compatibility improves communication and data interact between different systems.
• Flexibility: GUIDs can identify a variety of items, including objects, resources, transactions, and users. They can be used as database primary keys, network protocol unique identifiers, authentication session tokens, and other purposes.
• Security: GUIDs can improve security by making it more difficult for attacker to prepare or believe real identifiers, particularly when employed in cryptographic applications or systems for access control.
• Dependability: GUIDs are a stable method for uniquely identifying items in distributed systems, making sure data integrity, consistency, and referential integrity between many parts and services.

Disadvantages of GUID

• Insufficient Storage: An integer primary key is usually made up of 4 bytes, and a GUID has 16 bytes (128 bits) in compare. This may result in an important increase in storage needs, especially for large databases.
• Performance Effect: GUIDs that have bigger sizes may significantly slow down database searches, especially if used for indexing. Adding data with GUIDs as index clusters may be less efficient since they are not successive.
• Readability for humans: GUIDs are lengthy, complex character sequences that are difficult for people to understand or remember, in addition to sequential numbers. Fixing and data manipulation may become more difficult as a result.

Frequently Asked Questions on GUID – FAQs

What is the format of GUID?

A proper GUID format is {XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}, where X is a hex digit (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F). Consider that programs like GUIDGEN can generate GUIDs with lowercase characters.

Is GUID globally unique?

A GUID is also known as a UUID or “Universally Unique Identifier.” A GUID/UUID is a globally unique ID (string) that identifies a digital object (person, place, or thing) that has to be managed and made available for an extended period of time.

What is the default of GUID?

The default value for an integer is 0, a string is “”, and a boolean is false. Would you please kindly explain the default value for guid? The default GUID is {00000000-0000-0000-000000000000}. It’s basically binary zeros.

How many symbols are in GUID?

A proper GUID (Globally Unique Identifier) has to fulfill the following conditions: It should be a 128-bit value. It should be 36 characters long (32 hexadecimal characters plus four hyphens).