Support for textual annotation of originating repository method in generated (sql) statements [DATAJPA-365]

[spring-projects-issues]

Thomas Darimont opened DATAJPA-365 and commented

When a database administrator observes a performance problem (e.g. a slow query) it is often difficult
to determine which part of an application (e.g. in the context of an java application with spring-data-jpa which repository/method)
is the cause of the issue.

This feature proposes an extension to the sql statement generation mechanism:
Support for textual annotation of originating repository method in a generated sql statement
e.g. in the form of a comment (similar to regular query hints) that states the (simple) class Name of
the originating spring data repository as well the method which resulted in the statement.

This gives the database administrator as well as the application developer a more detailed hint where
to look for the performance problems in the application code.

Things to consider:
The comment mechanisms can be quite database dependent.
This feature is very generic and should actually be implemented at a lower (e.g. within the jpa itself).
May be one could use the jpa query hint facilities.

Here is a short example:

Without "originating repository method":

FooRepository.findBarWhereAttr1AndAttr2(..,..)

->

select 
* 
from foo where attr1, attr2

With "originating repository method":

FooRepository.findBarWhereAttr1AndAttr2(..,..) 

->

select 
/* FooRepository.findBarWhereAttr1AndAttr2 */ 
* from foo where attr1, attr2

---

No further details from DATAJPA-365

[spring-projects-issues]

Thomas Darimont commented

Hello,

we could generalize the recently introduced @Meta annotation from Spring Data MongoDB, move it
to SD commons and then use it's "comment" attribute to generate approprirate query hints to inject
the comment into the generated query.

Hibernate:
@QueryHints({ @QueryHint(name = "org.hibernate.comment", value = "test") })

EclipseLink:
@QueryHints({ @QueryHint(name = "eclipselink.sql.hint", value = "test") })

OpenJPA: 
???
{code9}

Cheers,
Thomas