Composite primary key and performance

Hi
I have a table with 110 columns.And PK for that table is a combination of 7 keys .
We need to schedule a daily job which will insert/update the table .Daily on a average( estimate) we have around 100000 insertion and same number of updates on the table .
So
is it a good option to keep the 7 keys as composite PK ?
Will it Effect the performance during DML operation on table ?
Is there any alternative to this problem ?
thanks in advance for your help

You define primary key as per business requirements. Its upto you to decide that you need 7 columns primary or not.
However, 100000 records a day wont be a big problem, unless if you are inserting them as bulk.
Jaffar

Similar Messages

Null in Composite Primary Key and "Primary keys must not contain null"

Hello all.
I'm a newbie concerning to JPA/EJB3, but I was wondering if toplinks doesn't support composite primary keys with null in some field (something perfectly right in any RDBMS).
I used JDeveloper (I'm using Oracle 10g database and JDeveloper 10.1.3.2.) wizards to generate JPA classes and I checked out generated files (with annotations), so they should be right (by the way, other O-R mappings for my model are working right, but this one).
I'm getting the next error:
Exception Description: The primary key read from the row [DatabaseRecord(
     TSUBGRUPOSLDI.CD_GRUP => 01
     TSUBGRUPOSLDI.CD_SUBGRUP => null
     TSUBGRUPOSLDI.CG_POBL => 058
     TSUBGRUPOSLDI.CG_PROV => 28
     TSUBGRUPOSLDI.DSCR => Sanidad)] during the execution of the query was detected to be null. Primary keys must not contain null.
Compound primary key is (CD_GRUP, CD_SUBGRUP). No foreign keys, no joins (only a NamedQuery: "select o from ..."). It's the simplest case!
I checked out that everything runs ok if there's no "null" value in CD_SUBGRUP.
After some research (this and other forums) I'm beginning to believe that it's not supported, but not sure.
Am I doing sth wrong? If not, what is the reason to not support this? Will it be supported in the future?
Thanks in advance.

Null is a special value and in many databases is not comparable to another null value (hence the isNull operator) and may pose problems when used to uniquely identify an Entity. TopLink does not support null values within a composite PK. As the nullable column is most likely not designated as a PK within your database table (many databases do not allow this) I recommend updating the Entity PKs to match that of the database.
--Gordon

Composite primary key and InputSelect

Hi
I have a jsp page where I have an InputSelect list that display the on of the field of a composite primary key.
What I what is to pass the second field of the primary key to my submit page without letting the user see that field.
<tr>
<td>Projekt</td>
<td>
<jbo:InputSelect multiple="false"
datasource="ds"
dataitem="ProjektId"
displaydatasource="proid"
displaydataitem="ProjektId"
displayvaluedataitem="ProjektId" />
</td>
</tr>
<tr>
<td></td>
<td>
<jbo:InputHidden datasource="ds"
dataitem="Kundenr" ></jbo:InputHidden>
</td>
</tr>
How can I automaticly give this hidden field it's value.
With kind regards Arnar Dagsson

How to implement this?
A has one to many relation ship with B
TABLE A
key A1 (primary key)
data A2
data A3
fkey B2 --> @OneToManyShouldn't this be (it is composite):
TABLE A
key A1 (primary key)
data A2
data A3
fkey B1 --> @OneToMany
fkey B2 --> @OneToMany
>
TABLE B
key B1 (primary)
key B2 (primary) <--- @ManyToOne
data B3
Tried to use @OneToMany and @ManyToOne but complains
about
@JoinColumns etc. Is this possible at all?If you can avoid having composite primary keys
Take a look at this message for my answer
http://forum.java.sun.com/thread.jspa?threadID=764754&messageID=4366595#4366595
Hope it helps

Urgent - ESB: DB Adapter with composite primary keys no returning any data

I have a DB Adapter in the ESB that inserts/updates/selects data to/from a table with 2 columns as primary keys, but table has several columns.
1. Initially, the db table had constraints for the composite primary key, The DB adapter had valid data coming in, but no result data.
2. Then I removed the db constraints on the composite primary key, and selected the 2 columns in the DB adapter wizard. Still, valid data is going in, since I am outputing to a file prior to call this node, but no result data is appearing. The result XML is empty.
Do I need to do something in Toplink for this?
The table spec is below. the ACCT_FIELD and ACCT_CODE columns make up the composite primary key.
CREATE TABLE AFF_DATA_SYNC
ACCT_FIELD NUMBER NOT NULL,
ACCT_CODE VARCHAR2(16) NOT NULL,
ACCT_EXISTS_FLAG VARCHAR2(1),
SAVE_ACCT_SEG_XML CLOB,
LAST_UPDATE_DATE DATE
The following xml is the request to the DB adapter:
<top:AffDataSyncReadDBAdapterSelect_accountField_accountCodeInputParameters xmlns:top="http://xmlns.oracle.com/pcbpel/adapter/db/top/AffDataSyncReadDBAdapter">
<top:accountField>8</top:accountField>
<top:accountCode>0003888</top:accountCode>
</top:AffDataSyncReadDBAdapterSelect_accountField_accountCodeInputParameters>
Log output:
JCA: esb:///ESB_Projects/STRIPES-AFF-Data-Intg_AFF-Data-Integration/AffDataSyncReadDBAdapter.wsdl [ AffDataSyncReadDBAdapter_ptt::AffDataSyncReadDBAdapterSelect_accountField_accountCode(AffDataSyncReadDBAdapterSelect_accountField_accountCode_inparameters,Af
DataSyncWipCollection) ] - No XMLRecord headers provided
JCA: <oracle.tip.adapter.db.DBInteraction executeOutboundRead> Executing query with arguments [8, 0003917]
JCA: <oracle.tip.adapter.db.TopLinkLogger log> SELECT ACCT_FIELD, ACCT_CODE, ACCT_EXISTS_FLAG, SAVE_ACCT_SEG_XML, LAST_UPDATE_DATE FROM
AFF_DATA_SYNC_WIP WHERE ((ACCT_FIELD = ?) AND (ACCT_CODE = ?))
bind => [8, 0003888]
JCA: <oracle.tip.adapter.db.DBInteraction executeOutboundRead> Read the following objects: []
Message was edited by:
user589357
Message was edited by:
user589357
Message was edited by:
user589357
Message was edited by:
user589357

The Toplink has no errors. Now I changed my table with only a single primary key, but for some reason, I am still getting no data.
JDeveloper 10.1.3.3 / SOA Suite (only using ESB) 10.1.3.3 with Oracle DB 10g 10.2.0.3.
1. What does No XMLRecord headers found mean?
2. Notice the last log item; Read ... []
Here are the log contents:
Invoking next service "AffDataSyncReadDBAdapterSelect_recordId" with payload :
<top:AffDataSyncReadDBAdapterSelect_recordIdInputParameters xmlns:top="http://xmlns.oracle.com/pcbpel/adapter/db/top/AffDataSyncReadDBAdapter">
<top:recordId>80003888</top:recordId>
</top:AffDataSyncReadDBAdapterSelect_recordIdInputParameters>
JCA: esb:///ESB_Projects/STRIPES-AFF-Data-Intg_AFF-Data-Integration/AffDataSyncReadDBAdapter.wsdl [ AffDataSyncReadDBAdapter_ptt::AffDataSyncReadDBAdapterSelect_recordId(AffDataSyncReadDBAdapterSelect_recordId_inparameters,AffDataSyncWipCollection)
] - No XMLRecord headers provided
JCA: esb:///ESB_Projects/STRIPES-AFF-Data-Intg_AFF-Data-Integration/AffDataSyncReadDBAdapter.wsdl [ AffDataSyncReadDBAdapter_ptt::AffDataSyncReadDBAdapterSelect_recordId(AffDataSyncReadDBAdapterSelect_recordId_inparameters,AffDataSyncWipCollection)
] - Starting JCA LocalTransaction
JCA: esb:///ESB_Projects/STRIPES-AFF-Data-Intg_AFF-Data-Integration/AffDataSyncReadDBAdapter.wsdl [ AffDataSyncReadDBAdapter_ptt::AffDataSyncReadDBAdapterSelect_recordId(AffDataSyncReadDBAdapterSelect_recordId_inparameters,AffDataSyncWipCollection)
] - Invoking JCA Outbound Interaction
JCA: <oracle.tip.adapter.db.DBInteraction executeOutboundRead> executing the NamedQuery: AffDataSyncReadDBAdapter.AffDataSyncWip.AffDataSyncReadDBAdapterSelect
JCA: <oracle.tip.adapter.db.DBInteraction executeOutboundRead> Parsing header record element.
JCA: <oracle.tip.adapter.db.TopLinkLogger log> client acquired
JCA: <oracle.tip.adapter.db.DBInteraction executeOutboundRead> Executing query with arguments [80003888]
JCA: <oracle.tip.adapter.db.TopLinkLogger log> SELECT RECORD_ID, ACCT_FIELD, ACCT_CODE, ACCT_EXISTS_FLAG, SAVE_ACCT_SEG_XML, LAST_UPDATE_DATE
FROM AFF_DATA_SYNC_WIP WHERE (RECORD_ID = ?)
bind => [80003888]
JCA: <oracle.tip.adapter.db.DBInteraction executeOutboundRead> Read the following objects: []
Message was edited by:
user589357
Message was edited by:
user589357

Composite primary key as foreign key not working

i want have two tables
in one table i make a composite primary key
and in the other table i refer one of the column of the composite key from the above table as foreign key in this table but this didn't work.
eg:
create table temp1
( name char2(10),
ssn# number(10)
address varchar2(10)
constraint (cons_1)primary key(name,ssn#) );
create table temp2
( name1 char2(10) references temp1(name),
add varchar(20));
this didn't work....can't create temp2 table it's giving error

The following includes some corrections and some suggestions. Your original code had several problems: missing comma, invalid name, invalid data type, no unique key for the foreign key to reference. The following fixes all of those and adds some meaningful names for the constraints and formats it so that it is easier to read.
CREATE TABLE temp1
(name       VARCHAR2 (10),
   ssn#       NUMBER   (10),
   address    VARCHAR2 (10),
   CONSTRAINT temp1_name_ssn#_pk
              PRIMARY KEY (name, ssn#),
   CONSTRAINT temp1_name_uk
              UNIQUE (name))
Table created.
CREATE TABLE temp2
(name1      VARCHAR2 (10),
   address    VARCHAR2 (20),
   CONSTRAINT temp2_name1_fk
              FOREIGN KEY (name1)
              REFERENCES temp1 (name))
Table created.

Composite Primary Key or Auto Increment key ?

Hi.. i have two ways for make something and don't know what's better ......
Problem : 3 tables
Client ----> ( 1,* ) Activity -----> (1,1) ActivityAccreditation
A Client it can have one or more activities, and one Activity have one ActivityAccreditation. On Client the primary key is CLIENT_ID, the two ways for generate the keys on the other tables are :
a ) On Activity the primary key is composed by CLIENT_ID and SEQUENCE_ACTIVITY ( a number than increment value by CLIENT_ID, example : CLIENT_ID = 1122 could have SEQUENCE_ACTIVITY from 1 to 3 for three activities, and CLIENT_ID = 1122 could have SEQUENCE_ACTIVITY from 1 to 4 for four activities ), and ActivityAccreditation have CLIENT_ID and SEQUENCE_ACTIVITY and ACCREDITATION_TYPE ( a code ).
b) On Activity the primary key is ACTIVITY_ID ( auto increment number ) with the CLIENT_ID like foreign key only. And on ActivityAccreditation have ACTIVITY_ACCREDITATION_ID like primary key and ACTIVITY_ID like foreign key.
The situation is than the numer of rows could to grow very much in the time ( 3.000.000 rows on ActivityAccreditation in one year and the database to be supported each five years ) and we don't know what solution is better by performance......
Tks.

I prefer the surrogate key.
I don't like composite keys as a rule because they tend to inject business logic into keys. Using surrogate keys eliminates this possibility.
For performance reasons, this means that you might want to create additional indexes on those columns to facilitate fast access. But my prejudice is to stick with surrogate keys.
I will admit that I'm not a DBA, so there are certain to be alternative views and arguments. We'll see if any of them pop up on this thread.

Composite Primary Key question

I have a new question regarding composite primary keys on another table I have created.
I have the following table with the following definition:
CREATE TABLE "APSOM"."CPULIST"
( "CPU_ID" VARCHAR2(10 BYTE),
"SERVER_ID" VARCHAR2(10 BYTE),
"CREATED_DATETIME" TIMESTAMP (6),
"UPDATED_DATETIME" TIMESTAMP (6)
with the following composite PK definition:
ALTER TABLE "APSOM"."CPULIST" ADD CONSTRAINT "CPULIST_PK" PRIMARY KEY ("CPU_ID", "SERVER_ID")
Then, I inserted data in the following way:
insert into CPULIST
values ('CPU1', 'P1', SYSDATE, SYSDATE);
with following CPU ID values from 'CPU1' to 'CPU16' for SERVER ID value 'P1' also inserted as well.
Now, I am trying to insert values for SERVER ID value 'P2'
insert into CPULIST
values ('CPU1', 'P2', SYSDATE, SYSDATE);
and I am getting the following error message:
Error starting at line 1 in command:
insert into CPULIST
values ('CPU1', 'P2', SYSDATE, SYSDATE)
Error report:
SQL Error: ORA-00001: unique constraint (APSOM.XPKCPULIST) violated
00001. 00000 - "unique constraint (%s.%s) violated"
*Cause: An UPDATE or INSERT statement attempted to insert a duplicate key.
For Trusted Oracle configured in DBMS MAC mode, you may see
this message if a duplicate entry exists at a different level.
*Action: Either remove the unique restriction or do not insert the key.
Using the following SQL command:
select column_name from all_cons_columns
where constraint_name = 'CPULIST_PK'
and owner = 'APSOM';
I get the following records
1. CPU_ID
2. SERVER_ID
This error does not make sense to me. Any help would be appreciated.
Thanks,
Patrick Quinn
Operations
Turning Point Global Solutions

So, if there is a hidden unique constraint XPKCPULIST that cannot be pulled the all_cons_column table and I drop the XPXCPULIST constraint with the following SQL:
alter table CPULIST drop constraint XPKCPULIST;
Error starting at line 1 in command:
alter table CPULIST drop constraint XPKCPULIST
Error report:
SQL Error: ORA-02443: Cannot drop constraint - nonexistent constraint
02443. 00000 - "Cannot drop constraint - nonexistent constraint"
*Cause:    alter table drop constraint <constraint_name>
*Action:   make sure you supply correct constraint name.
What can I do to get past this so I can perform the following insert and receive this error message??
insert into CPULIST
values ('CPU1', 'P2', SYSTIMESTAMP, SYSTIMESTAMP);
Error starting at line 1 in command:
insert into CPULIST
values ('CPU1', 'P2', SYSTIMESTAMP, SYSTIMESTAMP)
Error report:
SQL Error: ORA-00001: unique constraint (APSOM.XPKCPULIST) violated
00001. 00000 - "unique constraint (%s.%s) violated"
*Cause:    An UPDATE or INSERT statement attempted to insert a duplicate key.
For Trusted Oracle configured in DBMS MAC mode, you may see
this message if a duplicate entry exists at a different level.
*Action:   Either remove the unique restriction or do not insert the key.

Composite primary key on very large tables...

Hello
So I'm building a database where one of the tables will eventually have > 1 billion rows and was wondering about the primary key. The table will have 3 columns (sample_id, object_id, value) and so I was thinking instead of creating a surrogate key I would create a composite primary key on those 3 columns.... People will query either for sample_id = X or object_id = Y. I've created a composite index on object_id, sample_id and value and the query times have been fast < 2-3s per object_id. Although building that index takes some time (7-8 hrs) what would be the pros/cons to composite PK vs a unique index? I plan to do massive bulk uploads (50M records at a time) so I'll disable the constraints before loading.... These records will also be loaded in order so would a clustered table be appropriate?
thanks
steve

Hi,
As correctly said by steve,partition the table.
Create a unique index on single column and then even if ur query is not using that column which has index,use a HINT and make it to use the index.
If ur using joins on this table with other tables u can use use_hash hint which will improve performance.
Hope it helps.
Thanks

Error While Deploying A CMP Entity Bean With A Composite Primary Key

Hello all,
I have a problem deploying CMP Entity beans with composite primary keys. I have a CMP Entity Bean, which contains a composite primary key composed of two local stubs. If you know more about this please respond to my post on the EJB forum (subject: CMP Bean Local Stub as a Field of a Primary Key Class).
In the mean time, can you please tell me what following error message means and how to resolve it? From what I understand it might be a problem with Sun ONE AS 7, but I would like to make sure it's not me doing something wrong.
[05/Jan/2005:12:49:03] WARNING ( 1896):      Validation error in bean CustomerSubscription: The type of non-static field customer of the key class
test.subscription.CustomerSubscriptionCMP_1530383317_JDOState$Oid must be primitive or must implement java.io.Serializable.
     Update the type of the key class field.
     Warning: All primary key columns in primary table CustomerSubscription of the bean corresponding to the generated class test.subscription.CustomerSubscriptionCMP_1530383317_JDOState must be mapped to key fields.
     Map the following primary key columns to key fields: CustomerSubscription.CustomerEmail,CustomerSubscription.SubscriptionType. If you already have fields mapped to these columns, verify that they are key fields.Is it enough that a primary key class be serializable or all fields have to implement Serializable or be a primitive?
Please let me know if you need more information to answer my question.
Thanks.
Nikola

Hi Nikola,
There are several problems with your CMP bean.
1. Fields of a Primary Key Class must be a subset of CMP fields, so yes, they must be either a primitive or a Serializable type.
2. Sun Application Server does not support Primary Key fields of an arbitrary Serializable type (i.e. those that will be stored
as BLOB in the database), but only primitives, Java wrappers, String, and Date/Time types.
Do you try to use stubs instead of relationships or for some other reason?
If it's the former - look at the CMR fields.
If it's the latter, I suggest to store these fields as regular CMP fields and use some other value as the PK. If you prefer that
the CMP container generates the PK values, use the Unknown
PrimaryKey feature.
Regards,
-marina

Difference between primary key and primary index

Dear All,
Hi... .Could you pls tell me the difference between primary key and primary index.
Thanks...

Hi,
Primary Key : It is one which makes an entry of the field unique.No two distinct rows in a table can have the same value (or combination of values) in those columns.
Eg: first entry is 111, if you again enter value 111 , it doesnot allow 111 again. similarly for the strings or characters or numc etc. Remember that for char or numc or string 'NAME' is not equal to 'name'.
Primary Index: this is related to the performance .A database index is a data structure that improves the speed of operations in a table. Indices can be created using one or more columns, providing the basis for both rapid random lookups and efficient ordering of access to records. The disk space required to store the index is typically less than the storage of the table (since indices usually contain only the key-fields according to which the table is to be arranged, and excludes all the other details in the table), yielding the possibility to store indices into memory from tables that would not fit into it. In a relational database an index is a copy of part of a table. Some databases extend the power of indexing by allowing indices to be created on functions or expressions. For example, an index could be created on upper(last_name), which would only store the uppercase versions of the last_name field in the index.
In a database , we may have a large number of records. At the time of retrieving data from the database based on a condition , it is a burden to the db server. so whenever we create a primary key , a primary index is automatically created by the system.
If you want to maintain indices on other fields which are frequently used in where condition then you can create secondary indices.
Reward points if helpful.
Thanks,
Sirisha..

How to define Composite primary key for a Table

Hi ,
I am basically more into Java Programming , with little bit knowledge on Oracle as DataBase .so please excuse for my silly doubts .
Can anybody please tell me how to define a Composite Primary Key on a Table .
Thanks in advance .
Edited by: user672373773 on Sep 25, 2009 8:54 AM

Here is an example right out of the Oracle documentation and the syntax for adding PK since you mention adding a composite PK.
Example creating composite index
http://download.oracle.com/docs/cd/B19306_01/appdev.102/b14251/adfns_indexing.htm#sthref594
Syntax for adding a PK (composite or not)
alter table oooooooo.tttttttt
add constraint tttttttt_PK
primary key (sample_column2,
sample_column1)
using index
tablespace IDXSPC
pctfree 05
initrans 04
maxtrans 08
storage (initial 16k
next 16k
maxextents 32
pctincrease 0);
-- dictionary management with restricted storage, change as desired.
HTH -- Mark D Powell --

Composite Primary Key using cmp

How can an Entity Bean with Composite Primary Key using Container Managed Persistance (CMP) be Deployed using in WebLogic Server 8.1
pls help me

Your text is a bit confusing, but I think the answer is yes (it can be used). However, it would help to see the DDL that you are using (or that you propose to use) to avoid any misunderstandings. And please be specific about whether you are referring
to COLUMNS that are part of a primary key versus the primary key itself (whether it is composed of one column or multiple columns).
Lastly, why not just try it and see.

Composite Primary Key Error

I am using Sun One App Server PE8.
I have a class with a composite primary key field. When I place the following method in my Home interface:
public MyEjb findByPrimaryKey(MyEjbPrimaryKey pk) throws FinderException, RemoteException;I get the following error when deploying:
ejbFindByPrimaryKey(EjbPrimaryKey) is already defined in MyEjb1368202910_ConcreteImpl
    public MyEjbPrimaryKey ejbFindByPrimaryKey (MyEjbPrimaryKey key)However, If i remove this method from the Home interface, i get the following error when running the verification tool:
Error: No single arg findByPrimaryKey(PrimaryKeyClass) method was found in home interface class [ MyEjb ].However, I can still deploy the EAR successfully.
Another related symptom of this problem, is if I include the following method in my Home interface:
public MyEjb findByPrimaryKey(String pkField1, String pkField2) throws FinderException, RemoteException;And call this method, I get the following exception at runtime:
java.rmi.RemoteException: Bean class for ejb [MyEjb] does not define a method corresponding to [Home] interface method [public abstract MyEjb MyEjbHome.findByPrimaryKey(java.lang.String,java
.lang.String) throws javax.ejb.FinderException,java.rmi.RemoteException]I get these same problems with all EJB's that use composite keys. Has anyone else had this problem?
Thanks
toby

This is a CMP bean, with no ejbFindByPrimaryKey in the Bean class. Below, i have included the Home interface and the Bean class (with unneccessary code removed)
Thanks for looking at this for me.
BEAN CLASS
package lands.mc.bus.prod;
import java.rmi.*;
import java.util.*;
import javax.ejb.*;
public abstract class TopoMapBean implements EntityBean
private EntityContext entity;
public TopoMapBean()
public void setEntityContext(EntityContext ctx)
    entity = ctx;
public void unsetEntityContext()
    entity = null;
public TopoMapPrimaryKey ejbCreate(String mapName, String mapNumber, String mnemonic,String edition, String scale)
throws CreateException
    // call setters...
    return null;
public void ejbPostCreate( String mapName,
                                               String mapNumber,
                                         String mnemonic,
                                         String edition,
                                         String scale )
removed set/get methods
public void ejbStore() {}
public void ejbLoad() {}
public void ejbActivate() {}
public void ejbPassivate() {}
public void ejbRemove() {}
}HOME INTERFACE
package lands.mc.bus.prod;
import java.rmi.*;
import java.util.*;
import javax.ejb.*;
public interface TopoMapHome extends EJBHome
public TopoMap create(String mapName,
                        String mapNumber,
                        String mnemonic,
                        String edition,
                        String scale
throws CreateException, RemoteException;
public TopoMap findByPrimaryKey(String mapNumber, String edition) throws FinderException, RemoteException;
// doesnt deploy with this signature
// public TopoMap findByPrimaryKey(TopoMapPrimaryKey pkey) throws FinderException;
// have to use this method instead of findByPrimaryKey(String, String) above
public TopoMap findTopoMap(String mapNumber, String edition) throws FinderException, RemoteException;

Querying on the basis of some attribute of composite primary key

Hello,
I am looking for suggestion about querying just on the basis of one attribute of the composite primary key.
TO exemplify,
I have a 6 attributes example A1,A2,A3,A4,A5,A6.
A1,A2 and A3 together, serve as composite primary key.Now,because of the need of the project,I want to do querying on the basis of any A1,A2 or A3.One way I could think of is to have secondary indices on each of A1,A2,A3.
Can some one explain me roughly how to go about it?
I am a new user of BerkeleyDB Java Edition,hence not sure what would be a good way to do it.I understand one way to do it,would be to keep A1,A2,A3 in the Key class and A1,A2,A3,A4,A5,A6 in the value class as well.Then create secondary indices on the A1,A2 and A3 individually.
Can someone suggest a more efficient way?
Thanks,
Will appreciate any suggestions.
Prateek

Exactly as you said. Create secondary indices on each attribute you want to index off of. I don't use the Java interface, but what you pretty much need to do is form your secondary key like so:
skey: pkey_individual_attribute
skeysize: pkey_individual_attribute_sizeHow to do this is documented in the BDB Java API docs:
For example:
    class MyKeyCreator implements SecondaryKeyCreator {
        public boolean createSecondaryKey(SecondaryDatabase secondary,
                                            DatabaseEntry key,
                                            DatabaseEntry data,
                                            DatabaseEntry result)
            throws DatabaseException {
            // DO HERE: Extract the secondary key from the primary key and
            // data, and set the secondary key into the result parameter.
            return true;
    SecondaryConfig secConfig = new SecondaryConfig();
    secConfig.setKeyCreator(new MyKeyCreator());
    // Now pass secConfig to Environment.openSecondaryDatabaseThe extractor function used to construct the secondary index is passed the primary key and primary data - therefore all the data is available to you with no need to duplicate the key within the data itself. While the standard example is to use some part of the primary data to form a secondary key - there's absolutely nothing against using only a part of the primary key to form a secondary key instead. The only thing you have to do is slice up said primary key and construct the "result" parameter to be a single attribute. The backend API already knows which composite key this secondary entry will be associated with and as such will implicitly form the data (or as you called it "value") section of the index (which will be the composite primary key passed to it).
The primary key/data should consist of the composite A1,A2,A3 with only A4,A5,A6 as data.
The secondary->get() call (within the Java API) takes a key and provides back the primary key and primary data (basically the same as the db->pget() call in the C API). Since you've already indexed individual attributes, based off of the composite key, into their own respective databases - you just query from one of your secondary indexes with whatever specific attribute as the key. You then use the filled in primary key and primary data to work off of.

HOW TO GET COUNT IN OF COMPOSITE PRIMARY KEYS USING ECLIPSELINK

Hi all,
We are currently migrating our application form oracle 10g to 11 g and hence migrating from toplink to eclipselink.
we are unable to fire the count query and getting the following exception ...
Error Code: 909
Call: SELECT COUNT() FROM T_USER_MESSAGE t0, T_USER t2, T_MESSAGE_RECIPIENT t1 WHERE ((((t2.PERSISTENT_ID = ?) AND (t2.SITE_CODE = ?)) AND (t1.DELETED_BY_RECIPIENT = ?)) AND (((t2.PERSISTENT_ID = t1.RECIPIENT_ID) AND (t2.SITE_CODE = t1.RECIPIENT_SITE)) AND ((t0.PERSISTENT_ID = t1.MESSAGE_ID) AND (t0.SITE_CODE = t1.MESSAGE_SITE))))
bind => [13398610, 1, F]
please advise .
we suspect that this could be because of the composite primary key in one of the tables .
any pointers to specify how count(*) could be used in this scenario would be of great help ..
Thanks in advance

What is the query being used, include the JPQL/expression code.
What is the error message (I assume this is a database error?).
What version are you using, can you try the latest EclipseLink 2.1 release.
James : http://www.eclipselink.org

Composite primary key and performance

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