Incorrect table name in Meta-Data Schema appendix [BATCH-2853]

[spring-projects-issues]

Luigi Quitadamo opened BATCH-2853 and commented

Index suggested in docs (https://docs.spring.io/spring-batch/docs/current/reference/html/schema-appendix.html#recommendationsForIndexingMetaDataTables) doesn't match with tables created by spring batch.

 

Default Table Name	Where Clause	Frequency	MATCH
BATCH_JOB_INSTANCE	JOB_NAME = ? and JOB_KEY = ?	Every time a job is launched	For SqlServer this index already exists (created by constraint)
BATCH_JOB_EXECUTION	JOB_INSTANCE_ID = ?	Every time a job is restarted
BATCH_EXECUTION_CONTEXT	EXECUTION_ID = ? and KEY_NAME = ?	On commit interval, a.k.a. chunk	This table doesn't exist
BATCH_STEP_EXECUTION	VERSION = ?	On commit interval, a.k.a. chunk (and at start and end of step)
BATCH_STEP_EXECUTION	STEP_NAME = ? and JOB_EXECUTION_ID = ?	Before each step execution	Is it correct the order for index? JOB_EXECUTION_ID is a foreign key so probably a better index should be (JOB_EXECUTION_ID, STEP_NAME)

 

 Furthermore, probably system needs index on BATCH_JOB_EXECUTION_PARAMS.JOB_EXECUTION_ID because it has a foreign key constraint.

 

 

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Affects: 3.0.10, 4.2.0, 4.1.1

Referenced from: pull request #748

[fmbenhassine]

Index suggested in docs (...) doesn't match with tables created by spring batch.

There are no indexes suggested in this section, on the contrary, it mentions that DDL scripts do not include indexes:

Index declarations are not included in that DDL,  because there are too many
variations in how users may want to index, [..].
The following provides **some indication** [..], so that individual projects
can make up their own minds about indexing

So based on this statement, I would leave any decision about indexing to the user.

That said, I agree on the following:

BATCH_EXECUTION_CONTEXT | This table doesn't exist

Indeed, this table does not exist anymore (it has been removed in d272105#diff-9df3d792ac9c1d09e598d04018ee1f6eL71-L80). So the documentation should be updated accordingly (there is a PR for that, see #748).

[fmbenhassine]

Fixed in #748 and backported to 4.2.2 and 4.1.4.