Database / Google Spanner Database Interview questions
What is the difference between batch DML and partitioned DML?
| Batch DML | Partitioned DML |
| Groups several DML statements into one transaction. | Splits one large DML statement across many transactions internally. |
| Fully atomic - all statements commit or none do. | Not atomic as a whole - executes as independent sub-ranges. |
| Bound by normal transaction size and lock limits. | Designed for bulk updates/deletes across millions of rows. |
Batch DML is the right tool when you have several related, moderate-size statements that must succeed or fail together, like updating a handful of related tables in one logical change. Partitioned DML is built for maintenance-style operations, such as deleting rows older than a retention window across an entire large table, where wrapping the whole thing in a single transaction would exceed transaction limits or hold locks far too long.
Which DML mode is fully atomic across all its statements?
Which is designed for bulk deletes across millions of rows?
More Related questions...
