Best (most efficient) DataType to use for UUIDs as JPA IDs
I want to use UUIDs as IDs for my JPA Objects. I am currently just using a String to store the UUID. What would be more efficient? ...
uuid
Postgres + Hibernate + Java UUID
I want to use PostgreSQL's native UUID type with a Java UUID. I am using Hibernate as my JPA provider and ORM. If I try to save it directly, it is just saved as a bytea in Postgres. How can I do this? ...
What is the smallest way to store a UUID that is human readable?
What is the smallest way to store a UUID that is human readable and widely database compatible? I am thinking a char array of some sort using hex values? ...
Storing UUID as base64 String
I have been experimenting with using UUIDs as database keys. I want to take up the least amount of bytes as possible, while still keeping the UUID representation human readable. I think that I have gotten it down to 22 bytes using base64 and removing some trailing "==" that seem to be unnecessary to store for my purposes. Are there an...
Why does my UUID use too much time?
String s = UUID.randomUUID().toString(); return s.substring(0,8) + s.substring(9,13) + s.substring(14,18) + s.substring(19,23) + s.substring(24); I use JDK1.5's UUID, but it uses too much time when I connect/disconnect from the net. I think the UUID may want to access some net. Can anybody help me? ...
Configure Hibernate to use Oracle's SYS_GUID() for Primary Key
I am looking for a way to get hibernate to use oracle's SYS_GUID() function when inserting new rows. Currently my DB tables have SYS_GUID() as the default so if hibernate simply generated SQL that omited the value it should work. I have everything working, but it is currently generating the UUID/GUID in code using the system-uuid genera...
INT, BIGINT or UUID/GUID in Oracle, DB2, Derby and HSQLDB?
For our next project, we're considering to switch to UUIDs as primary keys for database tables. The project will run on HSQLDB, Derby, DB2 and Oracle, maybe MySQL. Data will not have to be migrated between databases (often), so the "uniqueness" over many DBs is not so much an issue for us. The main advantage for us currently is that eac...
Two Way Mapping using single Data Structure
I ran across some code recently at work (recreated to be similar to what I am dealing with) similar to the code below Is there a way I can rework the code below to use one data structure (with performance in mind)? Here is some code to illustrate what I mean: public class ObjectMapper { private Map<UUID,Integer> uuidMap; pri...
Converting UUIDs from one format to another
I have an SQL document formatted as so (It has about 3000 entries like so): INSERT INTO DATA(UUID, IS_SIMULATED, ENVIRONMENT) VALUES('99b857afcb2e4f7dbf8657ea916ad9d7',FALSE,'SPACE') INSERT INTO DATA(UUID, IS_SIMULATED, ENVIRONMENT) VALUES('df8480e333c044f08ada939c66fa13f5',FALSE,'AIR') INSERT INTO DATA(UUID, IS_SIMULATED, ENVIRONMENT) ...
When would you use GUIDs as primary keys?
Possible Duplicate: Advantages and disadvantages of GUID / UUID database keys Are there any circumstances where it is essential to use GUIDs as primary keys in a SQL Server 2005/8 DB. For example, does the use of the MS Sync Framework force this, or data replication? ...
Generating a Hardware-ID on Windows
What is the best way to generate a unique hardware ID on Microsoft Windows with C++ that is not easily spoofable (with for example changing the MAC Address)? ...
Why is an iPhone Device ID 40 characters?
UUIDs are usually 36 characters. ...
How to generate a GUID in VBScript?
I want to generate GUID strings in VBScript. I know that there's no built-in function in VBScript for generating one. I don't want to use random-generated GUIDs. Maybe there is an ActiveX object that can be created using CreateObject() that is sure to be installed on (newer) Windows versions that can generate a GUID? ...
Tool for ActiveX Control Capabilities
Is there a tool out there that allows me to browse all the ActiveX controls I have installed on my system and the methods and properties that I can access? And of course their UUIDs. ...
VC++ #import directive for GCC/G++
I'm trying to test out a library that provides a VC++ example; however, I use gcc/g++ for all of my projects. Well, the way the VC++ example accesses the library is it uses the #import directive, passing the location of the library DLL, then it does a using namespace LIBRARYNAME, and then it's able to create some undefined type (I'd ass...
Sending a Java UUID to C++ as bytes and back over TCP
I'm trying to send a Java UUID to C++, where it will be used as a GUID, then send it back and see it as a UUID, and I'm hoping to send it across as just 16 bytes. Any suggestions on an easy way to do this? I've got a complicated way of doing it, sending from Java to C++, where I ask the UUID for its least and most significant bits, wri...
How do I obtain/use LibUUID?
I'm trying to replace a call to ::CoCreateGUID so I can generate GUIDs in a C++ program on Linux. I understand that libuuid (http://linux.die.net/man/3/libuuid) supports this, and I've read this question (http://stackoverflow.com/questions/153676/guids-in-a-c-linux-gcc-app). I'm a bit new to Ubuntu/GCC/Linux, so I've started off like t...
How unique is UUID?
How safe is it to use UUID to uniquely identify something (I'm using it for files uploaded to the server)? As I understand it, it is based off random numbers. However, it seems to me that given enough time, it would eventually repeat it self, just by pure chance. Is there a better system or a pattern of some type to alleviate this issue?...
UUIDs and byte-swapping over network
Hi, Is there are a standard accepted way to byte-swap UUIDs for transmission over a network (or file storage)? (I want to send/store the 16 raw bytes rather than convert the UUID to a string representation.) I thought at first I should partition the UUID into 4 32-bit integers and call htonl on each of them, but that didn't smell right...
Is there any danger to creating UUID in Javascript client-side?
Hi, I need to generate UUID to eventually store in a database. Can I generate theses UUID from Javascript on the client browser (There are some examples here)? Is there any security risk of doing it this way? I understand that anyone can modify the UUID before it's passed to the server for storing. So i'll need to check if they are tru...