users@jpa-spec.java.net

[jpa-spec users] Re: Full text search

From: Christian Beikov <christian.beikov_at_gmail.com>
Date: Tue, 29 May 2012 14:10:20 +0200

Hello!

I have just read some lines of the documentation of hibernate search and
found out that the index is written transactional if a transaction
exists. In other words, the implementation would have to participate in
a JDBC or JTA transaction.

Here a little excerpt of the documentation(also see
http://docs.jboss.org/hibernate/search/3.2/reference/en/html_single/#d0e488):

    To be more efficient, Hibernate Search batches the write
    interactions with the Lucene index. There is currently two types of
    batching depending on the expected scope. Outside a transaction, the
    index update operation is executed right after the actual database
    operation. This scope is really a no scoping setup and no batching
    is performed. However, it is recommended - for both your database
    and Hibernate Search - to execute your operation in a transaction be
    it JDBC or JTA. When in a transaction, the index update operation is
    scheduled for the transaction commit phase and discarded in case of
    transaction rollback. The batching scope is the transaction. There
    are two immediate benefits:

      *

        Performance: Lucene indexing works better when operation are
        executed in batch.

      *

        ACIDity: The work executed has the same scoping as the one
        executed by the database transaction and is executed if and only
        if the transaction is committed. This is not ACID in the strict
        sense of it, but ACID behavior is rarely useful for full text
        search indexes since they can be rebuilt from the source at any
        time.

    You can think of those two scopes (no scope vs transactional) as the
    equivalent of the (infamous) autocommit vs transactional behavior.
     From a performance perspective, the /in transaction/ mode is
    recommended. The scoping choice is made transparently. Hibernate
    Search detects the presence of a transaction and adjust the scoping.

Adapting this would fulfill your requirement, wouldn't it?

Mit freundlichen Grüßen,
------------------------------------------------------------------------
*Christian Beikov*

Am 29.05.2012 09:08, schrieb Christian Romberg:
> Hi Christian,
>
> Normal indexes in standard ACID databases (regardless whether an RDBMS
> or an ODBMS like ours) are transactionally consistent.
>
> With full text indexes this becomes a problem, and I think this is the
> point, which would need to be discussed before discussing any
> integration in JPA.
>
> Regards,
>
> Christian
>
> On Sun, May 27, 2012 at 9:31 PM, Christian Beikov
> <christian.beikov_at_gmail.com <mailto:christian.beikov_at_gmail.com>> wrote:
>
> Before adding another issue to JIRA I wanted to discuss the following.
> Mark Struberg has added the issue for indices,
> http://java.net/jira/browse/JPA_SPEC-22
> Depending on this issue I would like to see something like full
> text search support/integration in JPA.
>
> Hibernate has the possibility, via hibernate search, to create
> full text queries. The entity manager interface would probably
> have to be extended if a similar approach would be offered in JPA.
> I would really like to see a standaradized way of integrating full
> text search in JPA via search providers or so.
>
> What do you think?
> --
> Mit freundlichen Grüßen,
> ------------------------------------------------------------------------
> *Christian Beikov*
>
>
>
>
> --
> Christian Romberg
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