[hibernate-dev] Database with UUID support

[Steve Ebersole]

The main drawback there imo is that it uses its own UUID implementation
(com.eaio.uuid.UUID) rather than simply generating java.util.UUID.  To
do so you have "bridge" as pointed out in the Cassandra FAQ:
http://wiki.apache.org/cassandra/FAQ#working_with_timeuuid_in_java

Not to mention the maven information he lists is inaccurate (there is no
repo at http://eaio.com/maven2) and the latest posts on that website are
from 2007.  

On Wed, 2010-05-26 at 15:30 -0600, Cody Lerum wrote:
> I prefer time based (version 1) UUID due the insert performance of random ID's.
> 
> Though that sends you down the road of using a third party generator.
> FWIW http://johannburkard.de/software/uuid/ is recommended on the
> Apache Cassandra wiki.
> 
> On Wed, May 26, 2010 at 2:24 PM, Steve Ebersole <steve at hibernate.org> wrote:
> > In regards to
> > http://opensource.atlassian.com/projects/hibernate/browse/HHH-3579 I am
> > trying to put together the best all around support for java.util.UUID we
> > can as a type.
> >
> > Obviously most databases "support uuid" via char/varchar data type.
> > Postgresql being the lone exception of which I am aware with their
> > special UUID datatype, even though they choose to map it to
> > java.sql.Types.OTHER (don't get me started).  So for sure we can support
> > UUID in every database.
> >
> > The next logical thought was supporting UUID as an identifier value.  If
> > we were to add that what I would really prefer is a way to obtain the
> > UUID ahead of time (pre-insert) which would mean knowing what databases
> > supported a UUID-generation function and, for those that did, what that
> > function is.  For those that do not, is using
> > java.util.UUID.randomUUID() a viable alternative?
> >
> > A list of major databases and their support/non-support for generating
> > UUID values that I know of are as follows:
> >
> > 1) postgresql - database itself does not support generation, instead
> > relying on an optional module called uuid-ossp
> > 2) mysql - supports generation via the UUID() function
> > 3) h2 - supports generation via the RANDOM_UUID()
> > 4) hsqldb - does not support generation afaict
> > 5) derby - does not support generation afaict
> > 6) db2 - does have a GENERATE_UNIQUE() function; was not able to tell if
> > that is compatible with java.util.UUID
> > 7) firebird - supports generation via GEN_UUID()
> > 8) informix - does not support generation afaict
> > 9) ingres - supports via UUID_CREATE()
> > 10) oracle - supports via SYS_GUID()
> > 11) maxdb (sapdb) - does not support generation afaict
> > 12) mssql (sql server) - does have a NEWID() function, though it
> > generates a string with hyphons in it; not sure how/if this value
> > relates to java.util.UUID
> > 13) sybase - like mssql also has a NEWID() function which here can
> > additionally be given a parameter to say whether to include hyphons etc;
> > again, not sure how/if this value relates to java.util.UUID
> > 14) terradata - does not support generation afaict
> >
> > DISCLAIMER : When I say "does not support" I mean in the base server
> > install.  As I pointed out with postgresql I understand some might have
> > additional optional or third-party modules that add such capabilities
> >
> >
> > So by my count, that means that we can have pretty complete support for
> > UUID on the following databases without any extra requirements:
> > a) mysql
> > b) h2
> > c) firebird
> > d) ingres
> > e) oracle
> >
> > Databases with potential support:
> > a) postgresql - is it reasonable to require this uuid-ossp module?
> > b) db2 - what is the compatibility of its GENERATE_UNIQUE() function
> > with java.util.UUID?
> > c) mssql/sybase - what is the compatibility of NEWID() function with
> > with java.util.UUID?
> >
> > For databases which do not support UUID generation, the question becomes
> > how do we support that in hibernate for identifiers?  Do we rely on
> > java.util.UUID.randomUUID()?  Do you use a special generator like
> > http://jug.safehaus.org/ ?  Other options?
> >
> > Also, if anyone notices issues in my db support investigations please
> > let me know.
> >
> > --
> > Steve Ebersole <steve at hibernate.org>
> > http://hibernate.org
> >
> > _______________________________________________
> > hibernate-dev mailing list
> > hibernate-dev at lists.jboss.org
> > https://lists.jboss.org/mailman/listinfo/hibernate-dev
> >


-- 
Steve Ebersole <steve at hibernate.org>
http://hibernate.org