patternsqlMinor
Does Postgres offer a feature like “NEWSEQUENTIALID” in MS SQL Server to make UUID as primary key more efficient
Viewed 0 times
newsequentialidprimarypostgressqlmakemorelikeefficientuuidoffer
Problem
Microsoft SQL Server offers the
Alternatively, MS SQL Server offers the
Creates a GUID that is greater than any GUID previously generated by this function on a specified computer since Windows was started. After restarting Windows, the GUID can start again from a lower range, but is still globally unique. When a GUID column is used as a row identifier, using NEWSEQUENTIALID can be faster than using the NEWID function. This is because the NEWID function causes random activity and uses fewer cached data pages. Using NEWSEQUENTIALID also helps to completely fill the data and index pages.
Is there a way to get the more efficiently-indexed UUID in Postgres?
NEWID command to generate a new GUID (the Microsoft version of UUID) value that can be used as a primary key value (in their uniqueidentifier data type). These are not sequential in nature, so updating an index can be inefficient.Alternatively, MS SQL Server offers the
NEWSEQUENTIALID command. To quote their documentation:Creates a GUID that is greater than any GUID previously generated by this function on a specified computer since Windows was started. After restarting Windows, the GUID can start again from a lower range, but is still globally unique. When a GUID column is used as a row identifier, using NEWSEQUENTIALID can be faster than using the NEWID function. This is because the NEWID function causes random activity and uses fewer cached data pages. Using NEWSEQUENTIALID also helps to completely fill the data and index pages.
Is there a way to get the more efficiently-indexed UUID in Postgres?
Solution
uuid-ossp modulePostgreSQL uses the standardized UUID generation algorithms provided by ITU-T Rec. X.667, ISO/IEC 9834-8:2005, and RFC 4122. From the docs on
uuid-ossp,The uuid-ossp module provides functions to generate universally unique identifiers (UUIDs) using one of several standard algorithms. There are also functions to produce certain special UUID constants.
uuid_generate_v1() This function generates a version 1 UUID. This involves the MAC address of the computer and a time stamp. Note that UUIDs of this kind reveal the identity of the computer that created the identifier and the time at which it did so, which might make it unsuitable for certain security-sensitive applications.So long as the MAC address does not change, you'll be golden.
That all said, I agree with @a_horse_with_no_name,
From my understanding this is only necessary in SQL Server because tables are stored in a clustered index which makes random insertions slower then with a heap table. Postgres has no such concept, so I don't think that would make a difference in Postgres
In fact, given the chance of fewer collisions and more security, I would take it. And to that I would use
uuid_generate_v4()uuid_generate_v4() This function generates a version 4 UUID, which is derived entirely from random numbers.Context
StackExchange Database Administrators Q#175107, answer score: 9
Revisions (0)
No revisions yet.