Changing batch size on causes the job to skip records about maintenance_tasks

[etiennebarrie]

We simply use job-iteration CSV batch enumerator. It does use the batch index as the cursor (the call to with_index after each_slice), which explains why changing the batch size would skip records.

> 100 rows, batch size: 10
cursor: nil: rows:  0- 9, next cursor: 0
cursor:   0, rows: 10-19, next cursor: 1
> change batch size to 20
cursor:   1, rows: 40-59, next cursor: 2 # missing rows 20-39

It could and maybe should be changed to use the row index as the cursor, allowing to change the batch size while still returning the correct records on the next iteration.

> 100 rows, batch size: 10
cursor: nil: rows:  0- 9, next cursor: 9
cursor:  9, rows: 10-19, next cursor: 19
> change batch size to 20
cursor:  19, rows: 20-39, next cursor: 39

While we could paper over it by changing the cursor information on this side, the fix should ultimately be in job-iteration.