Hi Kevin, Thanks for the reply!
We are enhancing the files. I have an Ant script enhancing the files before every run of OpenJPA, so that is not the problem. Although it did give me strange results the first time I tried openjpa and did not enhance ;) -Shubbis Kevin Sutter wrote: > > Hi Shubbis, > Thanks for asking before posting any results... :-) Much appreciated. > > The first thing that comes to mind is whether you are "enhancing" your > Entities that are used with OpenJPA. For optimal performance, OpenJPA > uses > a byte-code weaving technique to enhance the Entity objects. This > enhancement allows for more efficient interaction between the Entity > objects > and the OpenJPA runtime. > > This blog entry explains the various enhancement mechanisms available for > an > OpenJPA environment (build vs runtime): > http://webspherepersistence.blogspot.com/2009/02/openjpa-enhancement.html > > FYI, if you do not perform the byte-code enhancement either statically at > build time or dynamically at runtime, then OpenJPA falls back to a simpler > subclassing approach. This subclassing approach is meant for simple > out-of-the-box examples, and not for production or performance > comparisons. > This performance concern becomes especially noticeable with Eager type > relationship fetching like it looks your example is doing. > > Let's start with this enhancement processing. If you are doing > enhancement > and you are still hitting this performance concern, then we need to dig > further because we definitely do not see this type of performance concern > when we do our comparisons... :-) > > Thanks, > Kevin > > On Thu, Mar 12, 2009 at 7:22 AM, Shubbis <marius.jo...@broadpark.no> > wrote: > >> >> First post so bare with me, and I've search for quite a while and not >> found >> any answers. >> >> I'm working on a school project where we are testing performance with >> different ORM's compared to JDBC and I'm having a big issue with OpenJPA >> when using a ManyToMany relation. >> >> We're trying to do a simple select case where we run a for loop with 500 >> iterations while calling a findById method that returns the instance. >> >> Wearhouse instance = getOJPAEntityManager().find(Wearhouse.class, id); >> >> This takes roughly 1~ sec on JDBC and 1.2~ EclipseLink while it takes 10+ >> sec on OpenJPA. >> This only happens with ManyToMany! We have plenty of insert tests, select >> tests etc and all of them are much more similar, with openjpa winning and >> losing a few. >> >> Now, I'll gladly admit we dont have to much experience with this, but >> this >> strikes me as very odd. So, if anyone has any tips, comments or info I'll >> be >> glad to try it out. >> >> Thanks in advance! >> >> Marius >> >> Here are the two entities in question: >> >> package project.common.model; >> >> import java.util.*; >> >> import javax.persistence.*; >> >> @Entity >> public class Wearhouse { >> >> @Id >> @GeneratedValue(strategy = GenerationType.IDENTITY) >> private Integer wearhouseNr; >> private String wearhouseName; >> >> @ManyToMany(cascade={CascadeType.PERSIST}, fetch = >> FetchType.EAGER) >> @JoinTable( >> name="wearhouse_storagecategory", >> joincolum...@joincolumn(name="wearhouseNr"), >> >> inversejoincolum...@joincolumn(name="storagecategoryNr") >> ) >> private List<Storagecategory> storageCategories; >> >> public Wearhouse() { >> } >> >> public Wearhouse(String wearhouseName) { >> this.wearhouseName = wearhouseName; >> storageCategories = new ArrayList<Storagecategory>(); >> } >> >> public Integer getWearhouseNr() { >> return this.wearhouseNr; >> } >> >> public void setWearhouseNr(Integer wearhouseNr) { >> this.wearhouseNr = wearhouseNr; >> } >> >> public String getWearhouseName() { >> return this.wearhouseName; >> } >> >> public void setWearhouseName(String wearhouseName) { >> this.wearhouseName = wearhouseName; >> } >> >> public void setStorageCategories(List<Storagecategory> >> storageCategory){ >> this.storageCategories = storageCategory; >> } >> >> public List<Storagecategory> getStorageCategories(){ >> return storageCategories; >> } >> >> public void addStorageCategories(Storagecategory storagecategory) >> { >> if(storageCategories == null) >> storageCategories = new >> ArrayList<Storagecategory>(); >> storageCategories.add(storagecategory); >> >> } >> >> } >> >> >> >> package project.common.model; >> >> import java.util.*; >> >> import javax.persistence.*; >> >> @Entity >> public class Storagecategory { >> >> @Id >> @GeneratedValue(strategy = GenerationType.IDENTITY) >> private Integer storagecategoryNr; >> private String storageCategoryName; >> >> @ManyToMany(mappedBy="storageCategories", >> cascade={CascadeType.PERSIST}) >> private List<Wearhouse> wearhouses; >> >> public Storagecategory() { >> } >> >> public Storagecategory(String storageCategoryName) { >> this.storageCategoryName = storageCategoryName; >> } >> >> public Integer getStoragecategoryNr() { >> return this.storagecategoryNr; >> } >> >> public void setStoragecategoryNr(Integer storagecategoryNr) { >> this.storagecategoryNr = storagecategoryNr; >> } >> >> public String getStorageCategoryName() { >> return this.storageCategoryName; >> } >> >> public void setStorageCategoryName(String storageCategoryName) { >> this.storageCategoryName = storageCategoryName; >> } >> >> public List<Wearhouse> getWearhouses() { >> return wearhouses; >> } >> >> public void setWearhouses(List<Wearhouse> wearhouses) { >> this.wearhouses = wearhouses; >> >> //Wearhouse owns the relation, therefor we have to tell >> these >> //wearhouses this storargecategories is on of the >> wearhouse's >> storagecategories. >> for (Wearhouse wearhouse : wearhouses) >> wearhouse.addStorageCategories(this); >> } >> } >> -- >> View this message in context: >> http://n2.nabble.com/Slow-performance-with-OpenJPA-when-selecting-from-a-ManyToMany-relation.-tp2466994p2466994.html >> Sent from the OpenJPA Users mailing list archive at Nabble.com. >> >> > > -- View this message in context: http://n2.nabble.com/Slow-performance-with-OpenJPA-when-selecting-from-a-ManyToMany-relation.-tp2466994p2467417.html Sent from the OpenJPA Users mailing list archive at Nabble.com.
