Hi all,
I use OJB/ JDO API. I know i should forget here thinking the relational
way, but i wonder if my DB indexes are used when i execute a JDOQL query
on a field that is not a primary Key but just indexed field. (I ask this
because in case of Primary Key i suppose people here would suggest using
getObjectById())
Adding the index in my DB doesn't change anything so i suppose it is not
used, and wonder about querying a large table?
(Forgot to say : newbie question:-))
Here is my quick sample: Zip codes table with (stupid but for example)
idzip as PK meaning nothing, and the zip code as a String field on
which i added index in databse :
CREATE INDEX testIndex ON ZIP(zip);
JAVA CLASS
public class Zip implements Serializable {
private int idzip;
private String zip;
public void setIdzip(int newIdzip) {
this.idzip = newIdzip;
}
public void setZip(String newZip) {
this.zip = newZip;
}
}
REPOSITORY
<class-descriptor class="net.talkgroups.model.bean.Usazip"
table="USAZIP">
<field-descriptor name="idzip"
column="idzip" jdbc-type="VARCHAR" primarykey="true"/>
<field-descriptor name="zip" column="zip"
jdbc-type="VARCHAR" indexed="true" access="readonly"/>
<!-- also tried this
<index-descriptor name= "testIndex" unique= "true">
<index-column name= "zip"/>
</index-descriptor>
-->
</class-descriptor>
JDO QUERY
Query query = persistenceManager.newQuery(Usazip.class, "zip==param");
query.declareParameters("String param");
Collection collection = (Collection) query.execute("10001"); // 10001 is
zip code
I get these logs from DB:
050528 19:56:05 27 Query SELECT 1
27 Query SET autocommit=0
27 Query SELECT A0.IDZIP,A0.ZIP FROM ZIP A0
050528 19:56:15 27 Query commit
It is slow in all cases (with or without index), and much faster with
SQL in my DB client. (table is US zip codes)
Regards
Phil
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