[Lift] Re: Robust and clear ways to do performant JDBC?
ScalaJPA returns things as either Options or BufferWrappers. The limitation on entities is due to JPA wanting something implementing the Java Set, List, Map interfaces and not Scala's. User types are similarly not included in standard JPA 1.0, although there's talk of putting that into JPA 2.0. I'd definitely like to address some of these issues, but I'm not enough of a Scala wizard to work around the JPA limitations (yet) :) Derek On Sat, May 23, 2009 at 5:58 AM, Oliver Lambert olambo...@gmail.com wrote: When I want to have user defined types, I have to write them as a Hibernate hack to JPA - Id rather not be wedded to Hibernate.When I get a collection out of a returned entity, I have to use JCL to wrap it. I'd rather, have everything in Scala collections. When I have a read only entity, I'd like it to be immutable. In fact, maybe all entities should be, but thats probably too hard. I'm just taking about the lower layer of JPA that Derek's stuff hooks into - its OK for Java, it kind of sucks for Scala. Just my thoughts, don't expect anyone to agree. cheers Oliver On Sat, May 23, 2009 at 9:41 PM, Timothy Perrett timo...@getintheloop.euwrote: Lol! Sorry oliver... I remember now :) What did you have in mind for “scala solution using JPA”? Is this not what we have already? Cheers, Tim On 23/05/2009 12:33, Oliver Lambert olambo...@gmail.com wrote: Yes, I helped with the code! On Sat, May 23, 2009 at 9:28 PM, Timothy Perrett timo...@getintheloop.eu wrote: To what degree are you wanting to re-invent the wheel? Derek has done amazing work with JPA and Scala - the resulting output being scala-jpa and the jpa archetypes for lift. Are you familiar with them? Cheers, Tim On 23/05/2009 11:56, Oliver Lambert olambo...@gmail.com wrote: JPA is a ORM tool. I think it would be great if someone would create a Scala solution using JPA as the starting point - any takers? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Lift group. To post to this group, send email to liftweb@googlegroups.com To unsubscribe from this group, send email to liftweb+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/liftweb?hl=en -~--~~~~--~~--~--~---
[Lift] Re: Robust and clear ways to do performant JDBC?
Yes, I helped with the code! On Sat, May 23, 2009 at 9:28 PM, Timothy Perrett timo...@getintheloop.euwrote: To what degree are you wanting to re-invent the wheel? Derek has done amazing work with JPA and Scala - the resulting output being scala-jpa and the jpa archetypes for lift. Are you familiar with them? Cheers, Tim On 23/05/2009 11:56, Oliver Lambert olambo...@gmail.com wrote: JPA is a ORM tool. I think it would be great if someone would create a Scala solution using JPA as the starting point - any takers? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Lift group. To post to this group, send email to liftweb@googlegroups.com To unsubscribe from this group, send email to liftweb+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/liftweb?hl=en -~--~~~~--~~--~--~---
[Lift] Re: Robust and clear ways to do performant JDBC?
Lol! Sorry oliver... I remember now :) What did you have in mind for ³scala solution using JPA²? Is this not what we have already? Cheers, Tim On 23/05/2009 12:33, Oliver Lambert olambo...@gmail.com wrote: Yes, I helped with the code! On Sat, May 23, 2009 at 9:28 PM, Timothy Perrett timo...@getintheloop.eu wrote: To what degree are you wanting to re-invent the wheel? Derek has done amazing work with JPA and Scala - the resulting output being scala-jpa and the jpa archetypes for lift. Are you familiar with them? Cheers, Tim On 23/05/2009 11:56, Oliver Lambert olambo...@gmail.com wrote: JPA is a ORM tool. I think it would be great if someone would create a Scala solution using JPA as the starting point - any takers? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Lift group. To post to this group, send email to liftweb@googlegroups.com To unsubscribe from this group, send email to liftweb+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/liftweb?hl=en -~--~~~~--~~--~--~---
[Lift] Re: Robust and clear ways to do performant JDBC?
When I want to have user defined types, I have to write them as a Hibernate hack to JPA - Id rather not be wedded to Hibernate.When I get a collection out of a returned entity, I have to use JCL to wrap it. I'd rather, have everything in Scala collections. When I have a read only entity, I'd like it to be immutable. In fact, maybe all entities should be, but thats probably too hard. I'm just taking about the lower layer of JPA that Derek's stuff hooks into - its OK for Java, it kind of sucks for Scala. Just my thoughts, don't expect anyone to agree. cheers Oliver On Sat, May 23, 2009 at 9:41 PM, Timothy Perrett timo...@getintheloop.euwrote: Lol! Sorry oliver... I remember now :) What did you have in mind for “scala solution using JPA”? Is this not what we have already? Cheers, Tim On 23/05/2009 12:33, Oliver Lambert olambo...@gmail.com wrote: Yes, I helped with the code! On Sat, May 23, 2009 at 9:28 PM, Timothy Perrett timo...@getintheloop.eu wrote: To what degree are you wanting to re-invent the wheel? Derek has done amazing work with JPA and Scala - the resulting output being scala-jpa and the jpa archetypes for lift. Are you familiar with them? Cheers, Tim On 23/05/2009 11:56, Oliver Lambert olambo...@gmail.com wrote: JPA is a ORM tool. I think it would be great if someone would create a Scala solution using JPA as the starting point - any takers? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Lift group. To post to this group, send email to liftweb@googlegroups.com To unsubscribe from this group, send email to liftweb+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/liftweb?hl=en -~--~~~~--~~--~--~---
[Lift] Re: Robust and clear ways to do performant JDBC?
Interesting... Have you seen jorge's scala utils? Perhaps we could do some magic with that to manage translations between java.util.list etc to native scala types...? Cheers, Tim Sent from my iPhone On 23 May 2009, at 12:58, Oliver Lambert olambo...@gmail.com wrote: When I want to have user defined types, I have to write them as a Hibernate hack to JPA - Id rather not be wedded to Hibernate. When I get a collection out of a returned entity, I have to use JCL to wrap it. I'd rather, have everything in Scala collections. When I have a read only entity, I'd like it to be immutable. In fact, maybe all entities should be, but thats probably too hard. I'm just taking about the lower layer of JPA that Derek's stuff hooks into - its OK for Java, it kind of sucks for Scala. Just my thoughts, don't expect anyone to agree. cheers Oliver On Sat, May 23, 2009 at 9:41 PM, Timothy Perrett timo...@getintheloop.eu wrote: Lol! Sorry oliver... I remember now :) What did you have in mind for “scala solution using JPA”? Is this not what we have already? Cheers, Tim On 23/05/2009 12:33, Oliver Lambert olambo...@gmail.com wrote: Yes, I helped with the code! On Sat, May 23, 2009 at 9:28 PM, Timothy Perrett timo...@getintheloop.eu wrote: To what degree are you wanting to re-invent the wheel? Derek has done amazing work with JPA and Scala - the resulting output being scala- jpa and the jpa archetypes for lift. Are you familiar with them? Cheers, Tim On 23/05/2009 11:56, Oliver Lambert olambo...@gmail.com wrote: JPA is a ORM tool. I think it would be great if someone would create a Scala solution using JPA as the starting point - any takers? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Lift group. To post to this group, send email to liftweb@googlegroups.com To unsubscribe from this group, send email to liftweb+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/liftweb?hl=en -~--~~~~--~~--~--~---
[Lift] Re: Robust and clear ways to do performant JDBC?
Hey there, Is their a particular reason you wouldn't or couldn't use existing java persistence infrastructure inside your scala application? That's the recommended advice right now; JPA (for instance) will slot right into your app :-) Cheers, Tim On 22/05/2009 20:43, braver delivera...@gmail.com wrote: One of the huge drawbacks in beginning serious use of Scala is the lack of an accepted and documented way to talk to the databases such as PostgreSQL. Googling for scala.dbc examples pulls old stuff from 2007; there's a scala-query on github, which is promising, and abandoned dbc2, and dbc3 is... awaiting new language features! Some of my Scala-DB findings are documented in the blog at http://la.scala.la/, and none look satisfactory so far. So it looks like the way to do it right here, right now, is down to Java JDBC. I was glad to see an example of that in @dpp's book. I wonder if you guys can point to specific idioms of using JDBC with actors for data-heavy apps such as data mining? Since Lift is the heavy consumer of DBs, I believe you have the most experience with it! Cheers, Alexy --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Lift group. To post to this group, send email to liftweb@googlegroups.com To unsubscribe from this group, send email to liftweb+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/liftweb?hl=en -~--~~~~--~~--~--~---
[Lift] Re: Robust and clear ways to do performant JDBC?
On May 22, 7:06 pm, Timothy Perrett timo...@getintheloop.eu wrote: Hey there, Is their a particular reason you wouldn't or couldn't use existing java persistence infrastructure inside your scala application? That's the recommended advice right now; JPA (for instance) will slot right into your app :-) Tim -- thanks for the pointer; as I'm coming to JVM solely for Scala, I'm learning the acronyms as I go. So JPA is good for ORM, right? My problem is not a typical web app, but rather an intensive warehousing -- storing something like a web crawl. It involves maintaining workers stuffing XML into the database, and checking whether a record is already there. I plan to first try it with an RDBMS such as PostgreSQL, and/or DB2/Oracle if needed, on a multicore Linux server; if not enough, I'd explore other solutions such as Berkeley DB or distributed HBase. But first I want to see if just JDBC is enough, and in order to make sure I get it at its most efficient, I'd like to see how the pros do it -- preferably with some Scala goodness so it's not as verbose as just Java's. I saw Dave mention JNDI and found DBCP and JNDI-DBCP Howto, and wonder whether it's applicable for high- performance apps or is primarily for containers like Tomcat where you have to maintain the connection across invocations. For my purely DB- stuffing app, I have connections open in each process; the interesting question is, can I unleash e.g. 8 actors, for the 8 cores, and leverage JNDI-DBCP pool to make it efficient, or should I simply open a connection per actor? Cheers, Alexy --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Lift group. To post to this group, send email to liftweb@googlegroups.com To unsubscribe from this group, send email to liftweb+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/liftweb?hl=en -~--~~~~--~~--~--~---
