[Database] db.operation.batch.size records number of queries

[lmolkova]

semantic-conventions/model/registry/db.yaml

Lines 79 to 82 in d9842e5

	- id: db.operation.batch.size
	type: int
	stability: experimental
	brief: The number of queries included in a [batch operation](/docs/database/database-spans.md#batch-operations).

Number of queries and number of records could be different. I think we can make attribute name more descriptive to reflect this.

• If the intention is to record number of queries, we can do db.query.batch.size
• to record number of items, we can use something like db.request.records.count or db.response.records.count

Also, it seems we have the attribute defined in the registry, but not referenced in the conventions - we should probably reference it.

[lmolkova]

From some past discussion in database WG:

I was confused with the naming db.operation.batch.size, but db.query.batch.size would be even more confusing. So taking this concern back.

The last concern remains - we forgot to add db.operation.batch.size into span attributes table and only have it in the registry - that's the only action item remaining in this issue.