📁Auto-Clustering Agent

Helps you choose the right clustering keys and decide where to enable clustering, where to keep it, and where to remove it to save money.

Overview

Auto-Clustering Agent helps you choose and maintain the right clustering keys for your tables—so you can improve performance for queries running on top of those tables (better pruning, less scanning) while also reducing overall cost.

A big part of the cost optimization is identifying tables where Snowflake Automatic Clustering (auto-clustering) is enabled but not providing enough value, and recommending to disable auto-clustering (and in some cases also drop clustering keys) to avoid unnecessary spend.

What problem it solves

Choosing clustering keys is one of the highest-leverage optimizations in Snowflake—but it’s also easy to get wrong.

Common issues:

• clustering keys are defined, but don’t match real query filters, so queries still scan too much

• Snowflake auto-clustering is enabled on tables that don’t benefit, which increases cost

• clustering keys are a poor fit due to cardinality, so pruning value is limited

• the “right” key changes as workloads change, and manual tuning doesn’t keep up

Auto-Clustering Agent helps you continuously select better clustering keys (to improve performance), and also highlights where auto-clustering should be disabled to reduce cost.

Prerequisites

To start using Auto-Clustering Agent, please follow the following documentation page to provide Seemore the following permissions

• Agent enablement permissions (ability to start/run the agent in your environment)

• Permission to execute a customer-created function we use to fetch clustering health metadata (column/table clustering status) — not table data

Clustering concepts (quick refresher)

Snowflake stores data in micro-partitions and maintains micro-partition metadata that enables pruning (skipping irrelevant partitions during scans).

To cluster a table, you define the clustering key (using CLUSTER BY). The key can include multiple columns/expressions, and the order you specify matters.

Snowflake Automatic Clustering (auto-clustering) is the service that reclusters a table over time to maintain clustering based on the key you defined—and this service is what can incur additional cost.

Clustering is generally most cost-effective for tables that are queried frequently and don’t change frequently—start with a small set of tables and measure impact before expanding.

What the Auto-Clustering Agent does

List the tables currently using auto-clustering

The agent lists the tables where Snowflake auto-clustering is enabled, and provides an analysis for the top 10 tables by default.

For the rest of the tables, you can generate analysis ad hoc by clicking Generate analysis.

For each table, the agent provides:

• a Health Score

• a recommendation to Optimize, Keep, or Disable auto-clustering (and in some cases Drop clustering keys)

• an explanation for the decision (impact on query performance + auto-clustering cost)

• an estimated cost impact for applying the change (focused on the savings from disabling Snowflake auto-clustering)

Generating a report

If you want to handle the top recommendations first (instead of going one-by-one), use the report.

We provide a report for:

• Top 10 tables with auto-clustering enabled Recommendations focused mainly on disabling Snowflake auto-clustering where it doesn’t pay off, and on optimizing/keeping clustering keys where they do improve performance.

• Top 10 tables without auto-clustering enabled Recommendations to cluster the tables (including suggested clustering keys). You choose the approach:

  • Manual clustering (define clustering keys and manage it yourself)

  • Enable Snowflake auto-clustering (define clustering keys and then clustering is maintained automatically)

This helps you prioritize the biggest wins: better keys for performance, and disable auto-clustering where it’s wasting money.

Recommendation types

• For tables enabled with Auto-Clustering

  • Optimize Improve performance by adjusting clustering keys (or key order) to match real query filters—so pruning is better across queries.

  • Keep Auto-clustering is providing value and is likely cost-effective for this table.

  • Disable auto-clustering (and sometimes drop keys) Recommended when the ongoing Snowflake auto-clustering cost outweighs the benefit. In some cases, the agent also recommends dropping the clustering keys if they provide little/no value.

• For tables that are not clustered

  • Add to Auto-Clustering - including suggested clustering keys and full analysis of the reason

  • Don't Add - the table is not a good fit for Auto-Clustering

How to act on recommendations

For every recommendation, we provide the exact SQL commands you need — just copy-paste them into your Snowflake worksheet and run.

If the agent recommends disabling auto-clustering (and sometimes dropping keys)

Typical reasons:

• auto-clustering cost outweighs performance benefit (table is not queried enough, or pruning gains are low)

• clustering keys don’t match real query filters, so queries still scan too much

• column cardinality isn’t a good fit for clustering (too high or too low), so clustering provides little to no pruning value

• clustering keys themselves provide little/no value, so the agent may also recommend dropping the keys

Recommended actions:

• disable Snowflake auto-clustering for the table

• optionally drop clustering keys (if recommended)

If the agent recommends adding/optimizing clustering keys

Typical reasons:

• the table is frequently queried and better pruning can improve performance

• filters/usage patterns suggest strong pruning benefits

Recommended actions:

• define or optimize clustering keys by using the agent recommendations

• optionally enable Snowflake auto-clustering if you want Snowflake to maintain clustering automatically (with associated cost)

FAQ

• Will Auto-Clustering Agent change anything automatically? By default, the agent provides analysis + suggested clustering keys and generates copy-paste SQL. Applying changes depends on your workflow and permissions.

• What’s the main cost saving? Reducing unnecessary spend from Snowflake auto-clustering by recommending where to disable auto-clustering when it doesn’t provide enough value.

• Why do you sometimes recommend dropping clustering keys too? If the keys provide little/no pruning value (for example due to poor fit or cardinality), dropping them can simplify maintenance—especially when auto-clustering is being disabled anyway.