What would be the most efficient data type to store a UUID/GUID in databases that do not have a native UUID/GUID data type? 2 BIGINTs? And what would be the most efficient code (C# preferred) to convert to and from a GUID to that type? Thanks. ...
I'm building a database that will store information on a range of objects (such as scientific papers, specimens, DNA sequences, etc.) that all have a presence online and can be identified by a URL, or an identifier such as a DOI. Using these GUIDs as the primary key for the object seems a reasonable idea, and I've followed delicious and ...
I'm currently working on a program in C# that works with data from ACT!. To be able to search and update a record you need to use the GUID. The only way I have been able to get a GUID from the framework is when I create a new record. How can I retrieve GUIDs from existing records in ACT!? ...
I see these 2 acronyms thrown around, and I was wondering if there are any differences between a GUID and a UUID? ...
I have seen the GUID Collisons discussions but just wanted your thoughts on whether there could be a GUID collision if both clients accessed the same web page that generates the GUID at exactly the same time (- probably down to the micro-second) ? ...
In rpc.h, the GUID structure is declared as follows: typedef struct _GUID { DWORD Data1; WORD Data2; WORD Data3; BYTE Data4[8]; } GUID; I understand Data1, Data2, and Data3. They define the first, second, and third sets of hex digits when writing out a GUID (XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXX). What I never unders...
I am working on a database that usually uses GUIDs as primary keys. By default SQL Server places a clustered index on primary key columns. I understand that this is a silly idea for GUID columns, and that non-clustered indexes are better. What do you think - should I get rid of all the clustered indexes and replace them with non-cluste...
I know that when you add/change/remove methods in a COM interface you're supposed to change the interface/coclass GUID but what about type libraries. When should you change the type library's GUID? Do you change it if a GUID inside the type library has changed? Or should you only change it when something that doesn't have its own GUID w...
Hi, If you use a GUID as a password for a publicly facing application as a means to gain access to a service, is this security through obscurity? I think the obvious answer is yes, but the level of security seems very high to me since the chances of guessing a GUID is very very low correct? Update The GUID will be stored in a device,...
I have a list of n GUIDs and I need to hash them into a single value. This value could be the size of a Guid object or the size of an Int32, it doesn't really matter, but it does need to be statistically unique (say with a probably similar to MD5). So one approach could be to sort them, concatenate the bytes and take an MD5 hash of all...
Is there a built in function equivalent to .NET's Guid.NewGuid(); in Cocoa? My desire is to produce a string along the lines of 550e8400-e29b-41d4-a716-446655440000 which represents a unique identifier. ...
MS Access allows the numeric type GUID (in German it's called 'Replikations-ID', so I guess in English that would be 'replication id') which is stored as a 16 byte binary field in the database. I found how to access these fields in Delphi with TAdoQuery/TAdoTable using TGuidField(...).AsGuid, but now I want to execute an SQL-Query like ...
We have an application that generates simulated data for one of our services for testing purposes. Each data item has a unique Guid. However, when we ran a test after some minor code changes to the simulator all of the objects generated by it had the same Guid. There was a single data object created, then a for loop where the properti...
I would like to write a utility that will provide me with a relatively unique ID in Java. Something pretty simple, like x bits from timestamp + y bits from random number. So, how would I implement the following method: long getUniqueID() { long timestamp = System.currentTimeMillis(); long random = some random long ... ...
I need a Guid property in some attribute class like this: public class SomeAttribute : Attribute { private Guid foreignIdentificator; public Guid ForeignIdentificator { get { return this.foreignIdentificator; } set { this.foreignIdentificator = value; } } } But in attribute definition I can use only primiti...
I have a Guid.NewGuid() call that is creating an Empty Guid. What would cause such a problem and how can I fix it? Edit: The code: <WebMethod()> _ Public Function CreateRow(rowValue As String) as String Dim rowPointer As Guid = System.Guid.NewGuid() Dim rowPointerValue As String = rowPointer.ToString() Try Dim r...
I'm using TopLink as my ORM and MySQL as the DB. I traded my auto-increment primary keys for GUIDs for one of my tables (alright, not quite: I'm actually using a random 64 bit integer, but that's good enough for my needs). Anyway, now queries, which don't even use the key, are taking much longer. What can I do? ...
Hello, i wonder if there is a way to generate valid GUIDs/UUIDs where the first (or any part) part is a user-selected prefix. I.e., the GUID has the format AAAAAAAA-BBBB-CCCC-DDDD-DDDDDDDDDDDD, and I want to set any part to a pre-defined value (ideally the AAA's). The goal is to have GUIDs still globally unique, but they do not need to...
It is connected to BI and merging of data from different data sources and would make that process more smooth. And is there an optimal migration strategy from a database without Guids to a version with Guids without information losses? ...
What exactly is GUID? Why and where I should use it? I've seen references to GUID in a lot of places, and in wikipedia, but it is not very clear telling you where to use it. If someone could answer this, it would be nice. Thanks ...