Send hibernate-dev mailing list submissions to hibernate-dev(a)lists.jboss.org To subscribe or unsubscribe via the World Wide Web, visit https://lists.jboss.org/mailman/listinfo/hibernate-dev or, via email, send a message with subject or body 'help' to hibernate-dev-request(a)lists.jboss.org You can reach the person managing the list at hibernate-dev-owner(a)lists.jboss.org When replying, please edit your Subject line so it is more specific than "Re: Contents of hibernate-dev digest..." Today's Topics: 1. Optimizing reflection optimization (?????? ????????) 2. Database with UUID support (Steve Ebersole) 3. Re: Optimizing reflection optimization (Emmanuel Bernard) 4. Re: Database with UUID support (Cody Lerum) 5. Re: Database with UUID support (Steve Ebersole) 6. Re: Database with UUID support (Emmanuel Bernard) 7. Re: Database with UUID support (Steve Ebersole) 8. Re: Database with UUID support (Steve Ebersole) ---------------------------------------------------------------------- Message: 1 Date: Wed, 26 May 2010 19:29:01 +0300 From: ?????? ???????? <kirill.klenski(a)gmail.com&gt; Subject: [hibernate-dev] Optimizing reflection optimization To: hibernate-dev(a)lists.jboss.org Message-ID: <AANLkTimK4Aorz1EfWODJPwNo0f7HYGFO9DgWK3YvNZPb(a)mail.gmail.com&gt; Content-Type: text/plain; charset=ISO-8859-1 Hi, Recently my task involved enabling hibernate reflection optimization in our application. Versions used: hibernate-core-3.3.1.GA javassist-3.4.GA Below are some thoughts that hopefully could help to improve the product. 1. I have noticed that org.hibernate.bytecode.javassist.BulkAccessorFactory.findAccessors(...) is searching for accessor methods in the optimized entity class only. This means that the methods from the superclasses are not visible during BulkAccessor creation unless overridden by child classes. By enhancing the algorithm to search down the inheritance tree we could avoid creation of redundant methods which increase the code verbosity a lot. In our case almost all the entities are inherited from the base classes having the common entity properties defined, so the reflection optimization does not work for any of them until we override the inherited methods in all the child classes. The implementation is trivial, but I have got a ready prototype if anybody is interested. 2. It seems that it should be also possible to optimize the EntityTuplizer's getPropertyValue and setPropertyValue calls in the similar way how the getPropertyValues and setPropertyValues are currently optimized. Best regards, Kirill Klenski ------------------------------ Message: 2 Date: Wed, 26 May 2010 15:24:46 -0500 From: Steve Ebersole <steve(a)hibernate.org&gt; Subject: [hibernate-dev] Database with UUID support To: &quot;hibernate-dev(a)lists.jboss.org&quot; <hibernate-dev(a)lists.jboss.org&gt; Message-ID: <1274905486.21430.72.camel@apollo> Content-Type: text/plain; charset="UTF-8" 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(a)hibernate.org&gt; http://hibernate.org ------------------------------ Message: 3 Date: Wed, 26 May 2010 22:53:32 +0200 From: Emmanuel Bernard <emmanuel(a)hibernate.org&gt; Subject: Re: [hibernate-dev] Optimizing reflection optimization To: ?????? ???????? <kirill.klenski(a)gmail.com&gt; Cc: hibernate-dev(a)lists.jboss.org Message-ID: <C953A377-1572-4A88-8D16-B24ED07B387E(a)hibernate.org&gt; Content-Type: text/plain; charset=utf-8 Hi, Have you noticed a perf difference in your application with and without the patch? I am wondering if modern VMs have catched up with what Javassist does. On 26 mai 2010, at 18:29, ?????? ???????? wrote: > 1. I have noticed that > org.hibernate.bytecode.javassist.BulkAccessorFactory.findAccessors(...) is > searching for accessor methods in the optimized entity class only. This > means that the methods from the superclasses are not visible during > BulkAccessor creation unless overridden by child classes. By enhancing the > algorithm to search down the inheritance tree we could avoid creation of > redundant methods which increase the code verbosity a lot. In our case > almost all the entities are inherited from the base classes having the > common entity properties defined, so the reflection optimization does not > work for any of them until we override the inherited methods in all the > child classes. The implementation is trivial, but I have got a ready > prototype if anybody is interested. ------------------------------ Message: 4 Date: Wed, 26 May 2010 15:30:00 -0600 From: Cody Lerum <cody.lerum(a)gmail.com&gt; Subject: Re: [hibernate-dev] Database with UUID support To: Steve Ebersole <steve(a)hibernate.org&gt; Cc: &quot;hibernate-dev(a)lists.jboss.org&quot; <hibernate-dev(a)lists.jboss.org&gt; Message-ID: <AANLkTikQJ294O2IKpWye4lWYh9DvC6rpCujvyIk7cHnv(a)mail.gmail.com&gt; Content-Type: text/plain; charset=UTF-8 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(a)hibernate.org&gt; 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(a)hibernate.org&gt; > http://hibernate.org > > _______________________________________________ > hibernate-dev mailing list > hibernate-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/hibernate-dev > ------------------------------ Message: 5 Date: Wed, 26 May 2010 20:13:48 -0500 From: Steve Ebersole <steve(a)hibernate.org&gt; Subject: Re: [hibernate-dev] Database with UUID support To: Cody Lerum <cody.lerum(a)gmail.com&gt; Cc: &quot;hibernate-dev(a)lists.jboss.org&quot; <hibernate-dev(a)lists.jboss.org&gt; Message-ID: <1274922828.21430.94.camel@apollo> Content-Type: text/plain; charset="UTF-8" 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(a)hibernate.org&gt; 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(a)hibernate.org&gt; > > http://hibernate.org > > > > _______________________________________________ > > hibernate-dev mailing list > > hibernate-dev(a)lists.jboss.org > > https://lists.jboss.org/mailman/listinfo/hibernate-dev > > -- Steve Ebersole <steve(a)hibernate.org&gt; http://hibernate.org ------------------------------ Message: 6 Date: Thu, 27 May 2010 08:27:47 +0200 From: Emmanuel Bernard <emmanuel(a)hibernate.org&gt; Subject: Re: [hibernate-dev] Database with UUID support To: hibernate-dev(a)lists.jboss.org Message-ID: <4E2E28D3-0EBD-4826-AFCC-F5E562730654(a)hibernate.org&gt; Content-Type: text/plain; charset=us-ascii To his credit a UUID impl is not a 10 year project plan ;) I would not necessarily consider it abandonware rather than done. On 27 mai 2010, at 03:13, Steve Ebersole wrote: > and the latest posts on that website are > from 2007. ------------------------------ Message: 7 Date: Thu, 27 May 2010 06:12:40 -0500 From: "Steve Ebersole" <steve(a)hibernate.org&gt; Subject: Re: [hibernate-dev] Database with UUID support To: "Emmanuel Bernard" <emmanuel(a)hibernate.org&gt;, &quot;hibernate-dev(a)lists.jboss.org&quot; <hibernate-dev(a)lists.jboss.org&gt; Message-ID: <4bfe53af.8c43e70a.68d9.2a1d(a)mx.google.com&gt; Content-Type: text/plain; charset=UTF-8 The site is not just about the UUID generator project. &nbsp;He wrote posts on ohter subjects as well. My point there is more to the maven repo. &nbsp;How do we reference this? &nbsp;Are we ending up hosting another artifact? &nbsp;How do we even contact him to find out? -- Sent from my Palm Pre steve(a)hibernate.org http://hibernate.orgOn May 27, 2010 1:28 AM, Emmanuel Bernard & lt;emmanuel(a)hibernate.org <lt%3Bemmanuel(a)hibernate.org&gt;&amp;gt; wrote: To his credit a UUID impl is not a 10 year project plan ;) I would not necessarily consider it abandonware rather than done. On 27 mai 2010, at 03:13, Steve Ebersole wrote: &gt; and the latest posts on that website are &gt; from 2007. _______________________________________________ hibernate-dev mailing list hibernate-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/hibernate-dev ------------------------------ Message: 8 Date: Thu, 27 May 2010 07:01:49 -0500 From: Steve Ebersole <steve(a)hibernate.org&gt; Subject: Re: [hibernate-dev] Database with UUID support To: Emmanuel Bernard <emmanuel(a)hibernate.org&gt; Cc: &quot;hibernate-dev(a)lists.jboss.org&quot; <hibernate-dev(a)lists.jboss.org&gt; Message-ID: <1274961709.21430.116.camel@apollo> Content-Type: text/plain; charset="UTF-8" Anyway, the discussion here wrt this UUID project is all about generating the UUID value in Java. The first point is to determine whether there is any benefit to relying on the database to generate these for us in the cases when they can. Secondly there is the question of if we are going to do it in Java then what is the correct approach. Both libraries mentioned here (UUID and JUG) use MAC address resolution in building the uuid value. JUG is updating to use java.util.UUID, but relies on native code for mac-address-resoltion; UUID use its own UUID class but does not need native code for the mac-address-resolution (it uses OS-sniffing and system calls). Heck maybe we offer this as a strategy configurable with the Configuration/SessionFactory. interface UUIDGenerationStrategy extends Serializable { public int getGenerationVersion(); // informational public UUID generateUUID(SessionImplementor session); } But first things first... Do we use database uuid generation if supported? Is that itself perhaps just a strategy? On Thu, 2010-05-27 at 06:12 -0500, Steve Ebersole wrote: > The site is not just about the UUID generator project. He wrote posts > on ohter subjects as well. > > My point there is more to the maven repo. How do we reference this? > Are we ending up hosting another artifact? How do we even contact > him to find out? > > > > > > -- Sent from my Palm Pre > > steve(a)hibernate.org > http://hibernate.org > ______________________________________________________________________ > On May 27, 2010 1:28 AM, Emmanuel Bernard <emmanuel(a)hibernate.org&gt; > wrote: > > To his credit a UUID impl is not a 10 year project plan ;) I would not > necessarily consider it abandonware rather than done. > > On 27 mai 2010, at 03:13, Steve Ebersole wrote: > > > and the latest posts on that website are > > from 2007. > > > _______________________________________________ > hibernate-dev mailing list > hibernate-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/hibernate-dev -- Steve Ebersole <steve(a)hibernate.org&gt; http://hibernate.org ------------------------------ _______________________________________________ hibernate-dev mailing list hibernate-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/hibernate-dev End of hibernate-dev Digest, Vol 47, Issue 18 *********************************************