[Proposal]: Add batchBy() to group related records in batches

[norberttech]

Describe the Proposal

Introduce batching strategy that keeps related records together.

Current batchSize() splits data by fixed count, which breaks parent-child relationships (e.g., order line items split across batches). This causes referential integrity issues when batch processing involves DELETE+INSERT operations.

API Adjustments

Add batchBy(string $column, int $maxSize = PHP_INT_MAX) method:

data_frame()
    ->read($orders_with_line_items)
    ->batchBy('order_id', maxSize: 1000)
    ->write($destination)
    ->run();

Are you intending to also work on proposed change?

Yes

Are you interested in sponsoring this change?

None

Integration & Dependencies

No response

[norberttech]

During the implementation I realized that instead of using maxSize we actually need a minSize to keep batch sizes under control but also not split logically related batches together