[YCQL] Batch operatios vs Transactions

General
1

What guarantees do I have when using batch insert|update operations?

for (...) {
  batch.add(update.bind( ... <values for bind variables> ... ));
}

If one of the batch operations fails, do the others roll back? Or is atomicity applied only if the table is created with:

WITH transactions = { 'enabled' : true };

Can I use batch operations instead of explicit transactions?

2

Hi @yarosman

Yes, you need transactions for all or nothing atomicity.

Batches are for sending multiple operations in a single RPC, there’s no rollback like when the table has transactions.

3

@yarosman - I believe batched operations in YCQL are “UNLOGGED BATCH” equivalent where each insert is atomic, but the overall operation is not. It returns a list of failed inserts - meaning you can determine which operations in the batch failed vs succeeded.

If you use the BEGIN syntax, the whole batch itself is applied atomically.

4

Hello,
That means it doesn’t matter if I write UNLOGGED, LOGGED, or COUNTER, I will always get a result with both succeeded and failed operations, without all-or-nothing semantics.

Thank you!

5

For non-transaction, yes, those are the semantics. LOGGED/UNLOGGED/COUNTER is ignored and we default to our own semantics.

Another example is writes are always QUORUM.