Snowflake says cross-query learning cut a long-running query to 30 seconds

Snowflake says feedback borrowed from another query helped its optimizer cut a 19-join analytics query from almost two hours to 30 seconds. In an engineering post dated Oct. 6, 2026, the company described an extension to Optima Planning that learns from shared pieces of queries, rather than relying only on previous runs of the same query.

The reported production result came on a subsequent execution, using feedback from a structurally similar but distinct query. Snowflake identifies the customer only as a large U.S.-based healthcare technology company. Separately, it says the mechanism can help a genuinely new query on its first run, provided a relevant piece of its plan has appeared in an earlier query.

The problem is one of estimation. Snowflake’s cost-based optimizer estimates how many rows each operation will produce, then uses those estimates to choose an execution plan. A bad estimate can send it toward the wrong join order or build side. In the healthcare customer’s example, Snowflake says an underestimated join produced billions of intermediate rows; feedback allowed the optimizer to choose a better join order and avoid that expansion.

To find reusable experience, Optima Planning computes hashes for plan fragments and individual operators, such as joins, after compilation. Those hashes describe the optimizer’s output—not the query’s SQL text. A different query with a matching piece can therefore draw on execution feedback even if the rest of its plan is new. An analyst adding a join to an established view is one example Snowflake gives.

A match does not automatically authorize reuse. Snowflake says the system checks whether feedback would overgeneralize from one context to another and withholds it when that transfer looks too aggressive. Cross-query feedback complements the existing per-query mechanism, which takes over when the new query runs again.

There is a visibility limitation for customers trying to identify these improvements. Query Profile and the QUERY_INSIGHTS view report when Optima Planning has helped, but Snowflake says they do not distinguish feedback borrowed from another query from feedback learned through repeats of the same one.