Avoid multiple DB Calls during sequence generation

aliabbasb · **Joined:** Fri Dec 17, 2004 3:08 pm **Posts:** 3

Hi,

I'm using the Oracle sequence generation to insert a new row into my detail tables.
I noticed that Hibernate generates 2 calls to the db for each insert..
1. To generate sequence.nextval
2. The actual insert

Is there any way that I could reduce this to just one call, and still continue using sequences? We have a home-grown persistence layer that I want to replace and that uses the sequence.nextval within the insert statement, thereby reducing one call. This is having a decent performance impact if I try to insert 100 + rows (about 2 seconds slower).

Thank you for your help..

Hibernate version: 2.1

Code:

Mapping documents:
    <id
        name="tradeOrderDetailId"
        type="java.lang.Integer"
        column="TRADE_ORDER_DETAIL_ID"
    >
        <meta attribute="field-description">
           @hibernate.id
            generator-class="sequence"
            type="java.lang.Integer"
            column="TRADE_ORDER_DETAIL_ID"

           @hibernate.generator-param
           name="sequence"
           value="trade_order_detail_seq"
        </meta>
        <generator class="sequence">
            <param name="sequence">trade_order_detail_seq</param>
        </generator>
    </id>

Name and version of the database you are using: Oracle 9i

The generated SQL (show_sql=true):

[java] Hibernate: select trade_order_detail_seq.nextval from dual
[java] Hibernate: insert into TRADE_ORDER_DETAIL (TRADER_NAME, SUIT_CHECK, SOLICITATION, SETTLEMENT_TYPE, DEALER_PR
ICE, QTY_TYPE, PRICING_METHOD, CUSTOMER_CONTACT, ORDER_DURATION, NOTIFY_ISSUER, IS_PROJECTED_SETTLEMENT, INFLATION_ACCRU
AL, INDEX_FACTOR, FACTOR_DATE, COMMISSION_TYPE, CREATION_DATE, UPDATE_DATE, CREATED_BY, DEALER_CONTACT, EXCHANGE, OPEN_Q
TY, QUOTE_DISCOUNT, RECORD_LOCKED_TIME, INVENTORY_ACCOUNT, COMMENTS, AGENT_DEALER, ERROR_CODE, ERROR, NUMBER_OF_SUB_ACCO
UNTS, CHANNEL, CONFIRM_MESSAGE, IS_BOOKED, UPDATED_BY, LORD_MESSAGE, BOOKING_MESSAGE, TRADE_ORDER_ID, TRADE_ORDER_DETAIL
_ID) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?,
?)
[/code]

anthony · **Posted:** Fri Dec 17, 2004 3:29 pm

http://blog.hibernate.org/cgi-bin/blosx ... find&path=

pretty sure this overhead is not only due to the sequence call.

max · **Posted:** Fri Dec 17, 2004 5:09 pm

hibernate need to get the id of the generated value somehow otherwise your object won't be equal to what is stored in the db.

I don't know if the JDBC3 generatedkeys can be used here ? (haven't played with that yet - but that is supported in H2)

michael · **Posted:** Fri Dec 17, 2004 10:28 pm

using SeqHiLo would also be a possibility