Re: Performance issues
Ok, now I see why! findAll( Class, Collection ) actually executes one transaction for each PK in the collection!! Here is an excerpt of the log. 8428 openjpa TRACE [$Proxy26:1240220275057:task1] openjpa.jdbc.SQL - t 27011334, conn 15221176 executing prepstmnt 30712384 SELECT t0.value, t1.TERMVO_ID, t1.element FROM mesh2_terms t0 LEFT OUTER JOIN mesh2_terms_variants t1 ON t0.id = t1.TERMVO_ID WHERE t0.id = ? [params=(String) T360914] 138430 openjpa TRACE [$Proxy26:1240220275057:task1] openjpa.jdbc.SQL - t 27011334, conn 15221176 [2 ms] spent Is there a way I can get everything done in one batch transaction rather than hundreds or thousands of transactions? Thank you! =David On Mon, 2009-04-20 at 13:49 +0900, David Leangen wrote: Thank you, I'll give that a try. On Fri, 2009-04-17 at 07:55 -0700, Paul Copeland wrote: That sounds interesting. You might turn on verbose logging for SQL operations (openjpa.jdbc.SQL) and see what queries are actually being executed. The logging section of the OpenJPA manual explains this. On 4/17/2009 3:41 AM, David Leangen wrote: Hello, I'm not at all an expert in databases, so I don't know if this is a JPA thing or a DB thing. In any case, I'm using Postgresql. Using the findAll( Class, Collection ) method, I am doing a lookup by PK. Since there is an index like so on the table: table_pkey PRIMARY KEY, btree (id) I would have expected the lookup to be very fast. With a collection of about 100 ids, the lookup takes almost 30 seconds, which does not seem right to me. Any ideas where I should begin to look? Thanks! =David
Can't query against a MappedSuperclass
I have the following:
@MappedSuperclass class A { }
@Entity class B extends A { }
@Entity class C extends A { }
and I try to do this type of query: SELECT a FROM A a
I receive error message An error occurred while parsing the query filter
SELECT a FROM A a. Error message: The name A is not a recognized
entity or identifier. Perhaps you meant B, which is a close match. Known
entity names: [B, C]
A is defined in my persistence.xml and my tables do have the inherited
fields from it so I'm pretty sure jpa is recognizing it.
The OpenJPA doc says that the query is supported.this is from the 1.2.0
doc:
Note
OpenJPA allows you to query on mapped superclasses. A query on a mapped
superclass will return all matching subclass instances.
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Re: Can't query against a MappedSuperclass
In the same documentation the following is stated and this was always
my definition of querying mappedSC.
Section 1.3
A mapped superclass is a non-entity class that can define persistent
state and mapping information for entity subclasses. Mapped
superclasses are usually abstract. Unlike true entities, you cannot
query a mapped superclass, pass a mapped superclass instance to any
EntityManager or Query methods, or declare a persistent relation with
a mapped superclass target. You denote a mapped superclass with the
MappedSuperclass marker annotation.
So whats correct here? The Note says the opposite... Perhaps it
should be made clearer but i always thought that the note is not true,
because in my code, i experienced the same as Jim.
So any feedback from the core team appreciated
---
regards
Marc Logemann
http://www.logemann.org
http://www.logentis.de
Am 20.04.2009 um 21:38 schrieb jim weaver:
I have the following:
@MappedSuperclass class A { }
@Entity class B extends A { }
@Entity class C extends A { }
and I try to do this type of query: SELECT a FROM A a
I receive error message An error occurred while parsing the query
filter
SELECT a FROM A a. Error message: The name A is not a
recognized
entity or identifier. Perhaps you meant B, which is a close match.
Known
entity names: [B, C]
A is defined in my persistence.xml and my tables do have the inherited
fields from it so I'm pretty sure jpa is recognizing it.
The OpenJPA doc says that the query is supported.this is from
the 1.2.0
doc:
Note
OpenJPA allows you to query on mapped superclasses. A query on a
mapped
superclass will return all matching subclass instances.
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Re: OPENJPA_SEQUENCE_TABLE: needed even with IDENTITY columns?
1. To verify that OPENJPA_SEQUENCE_TABLE is not getting created by another
entity, can you run the application with a single simple class such as
@Entity
public class PObject {
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
private long id;
public long getId() {
return id;
}
}
2. What is the resultant schema for PObject on H2 database?
ljnelson wrote:
Hello. I am using the H2 database for some simple unit tests, with
OpenJPA sitting on top of it.
I am wondering how to get OpenJPA to stop trying to create or look for the
OPENJPA_SEQUENCE_TABLE, particularly since nothing in my entity model
requires it (I explicitly use the @GenerationType of IDENTITY, which I
took it was supposed to use the native auto-incrementing ability of the
database, if there is one (which there is in H2).
Could someone tell me either how to instruct OpenJPA to basically insert
NULL into the primary key column instead of trying to insert a value it
thinks it can get from the non-existent OPENJPA_SEQUENCE_TABLE? If I
wanted to use a table, I would have used @GenerationType.TABLE, not
@GenerationType.IDENTITY.
Thanks very much!
Best,
Laird
-
Pinaki Poddar http://ppoddar.blogspot.com/
http://www.linkedin.com/in/pinakipoddar
OpenJPA PMC Member/Committer
JPA Expert Group Member
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Re: OPENJPA_SEQUENCE_TABLE: needed even with IDENTITY columns?
I should briefly mention that I had the same problem using the MySql
database.
I'm sure I'm not using the SEQUENCE table because I manually created my
database tables and I was just migrating to using the schema generator.
In my case it was tracked down to using an @EmbeddedId in the model class
@EmbeddedId
private FacilityIdIntegerCompositePk facilityDemographicPk;
the @Embeddable class contained 2 Integers with no annotations.
private Integer integratorFacilityId = null;
private Integer caisiItemId = null;
I just ignored it as it wasn't creating any problems for me. My
application still runs fine and there's not a single row in the sequence
table.
On Mon, Apr 20, 2009 at 02:18:13PM -0700, Pinaki Poddar wrote:
1. To verify that OPENJPA_SEQUENCE_TABLE is not getting created by another
entity, can you run the application with a single simple class such as
@Entity
public class PObject {
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
private long id;
public long getId() {
return id;
}
}
2. What is the resultant schema for PObject on H2 database?
ljnelson wrote:
Hello. I am using the H2 database for some simple unit tests, with
OpenJPA sitting on top of it.
I am wondering how to get OpenJPA to stop trying to create or look for the
OPENJPA_SEQUENCE_TABLE, particularly since nothing in my entity model
requires it (I explicitly use the @GenerationType of IDENTITY, which I
took it was supposed to use the native auto-incrementing ability of the
database, if there is one (which there is in H2).
Could someone tell me either how to instruct OpenJPA to basically insert
NULL into the primary key column instead of trying to insert a value it
thinks it can get from the non-existent OPENJPA_SEQUENCE_TABLE? If I
wanted to use a table, I would have used @GenerationType.TABLE, not
@GenerationType.IDENTITY.
Thanks very much!
Best,
Laird
-
Pinaki Poddar http://ppoddar.blogspot.com/
http://www.linkedin.com/in/pinakipoddar
OpenJPA PMC Member/Committer
JPA Expert Group Member
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--
Ted Leung
ted...@sfu.ca
I am what what the world has taught me to be.
Problems in setting up the work enviroment.
Hello, I am new GSOC guy and I will be working on the Slice module. I was trying to set up my development environment and downloaded the 1.2.1 release for the same. I was trying to compile the hellojpa program given in example folder but it is not able to find javax.persistence package. Actually there is no persistence package in my standard java distribution. Can someone please tell me how to sort out this problem. Also is there some eclipse plugin to work with OpenJPA. Being new to this type of work environment, I might be asking lot of stupid questions at first, so please bear with me. thanks and regards -- Ashish Paliwal Mobile : 9305128367 IIT Kanpur India
