---
title: "Data clean rooms collaboration"
excerpt: "Data clean rooms collaboration on hashed IDs: aggregate-only joins on Snowflake, AWS, and in-house columnar stores."
authors: "Tinybird"
categories: "AI Resources"
createdOn: "2026-09-07 00:00:00"
publishedOn: "2026-09-07 00:00:00"
updatedOn: "2026-09-07 00:00:00"
status: "published"
---

**Data clean rooms collaboration** lets a retailer and a CPG brand measure campaign lift without either side downloading the other's customer list. The join runs in an environment both contracts trust. Outputs are aggregates with suppression rules, not row-level exports. When it works, attribution improves and legal sleep improves. When it fails, someone exported a "summary" CSV with reversible keys.

Clean rooms are policy-wrapped compute, not a magic compliance checkbox. Success depends on identifier rules, allowed query templates, egress controls, and audit logs someone actually reads.

## What a clean room guarantees (and what it does not)

| Guarantee | Typical mechanism | Not covered |
| --- | --- | --- |
| No raw row export | Query result policies, blocked COPY | Screenshots and manual notes |
| Minimum cohort size | HAVING count >= k | Analyst subqueries that bypass templates |
| Allowed join keys | Hashed email / loyalty ID only | New keys added without DPA update |
| Audit trail | Per-query logs with identity | Shared login credentials |
| Time-bound access | Room expiration dates | Forgotten service principals |

Clean rooms **collaborate on intersection statistics**. They do not replace DPAs, brand safety review, or your own identity resolution quality.

## Vendor landscape in plain terms

**Snowflake Clean Rooms** run inside Snowflake accounts with native policies and consumer/provider roles. Familiar when both parties already warehouse there.

**AWS Clean Rooms** target AWS-centric data with cryptographic controls and analysis templates. Common when S3 and Glue already hold partner feeds.

**Google Ads Data Hub / PAIR-style flows** focus on ads measurement with publisher and advertiser separation.

**Habu, InfoSum, and specialist vendors** package policy UI, identity translation, and billing for media use cases.

**In-house ClickHouse® or BigQuery projects** with row policies, private service connect, and manual query review when neither side wants a third platform.

Pick based on **where data already lives** and **who owns audit**, not based on the flashiest zero-trust diagram in the sales deck.

## Collaboration workflow that survives legal review

1. **Define the question.** "Overlap count by campaign" is in scope. "Give me emails of buyers" is not.
2. **Agree hashing v1.** Normalization, salt scope, rotation policy. Document in the contract appendix.
3. **Upload or grant read** to tokenized tables only. Raw PII never enters the room if avoidable.
4. **Run templated queries** or stored procedures both sides pre-approved.
5. **Export aggregates** that pass k-anonymity. Log who exported what.
6. **Expire the room** or rotate keys when the campaign ends.

Skipping step one is why rooms fill with exploratory SQL that compliance has to unwind.

## Identity inside the room

Clean room collaboration assumes both parties tokenized identifiers the same way **or** a third-party identity provider translated keys inside the room. Mismatch examples:

- Partner A hashes lowercase email with salt X
- Partner B strips plus-tags differently
- Overlap counts read zero while business knows traffic existed

Run **hash validation queries** on known test vectors before campaign SQL. [Privacy-preserving identity resolution](https://www.tinybird.co/blog/privacy-preserving-identity-resolution) covers deterministic vs probabilistic links and confidence metadata. Clean rooms consume those rules; they do not invent them.

## Query patterns: allowed vs blocked

**Allowed:**

```sql
SELECT
    campaign_id,
    count() AS exposed_users,
    countIf(converted) AS converters
FROM joined_events
GROUP BY campaign_id
HAVING exposed_users >= 250
```

**Blocked or policy-rejected:**

```sql
SELECT user_token, purchase_amount
FROM joined_events
WHERE campaign_id = 'spring_sale'
LIMIT 100000
```

Good rooms enforce blocked patterns at the platform layer. Great rooms only expose parameterized templates so free-form SQL never enters the UI.

## When clean rooms feel slow

Vendor rooms charge for scan volume and cross-cloud egress. A naive join between billion-row logs and hundred-million-row CRM extracts gets expensive fast. Mitigations teams use in production:

- **Pre-aggregate** each side to campaign × day × token before the room join
- **Filter date windows** aggressively in policy templates
- **Partition** by market so rooms stay regional
- **Materialize overlap daily** instead of rejoining raw history per ad hoc question

Columnar OLAP outside the vendor room often holds pre-aggregated partner tables for operational dashboards while the clean room remains the legal venue for official measurement.

[ClickHouse for time series metrics, rollups, and SLOs](https://www.tinybird.co/blog/clickhouse-time-series-data) describes rollup tiers that keep collaboration queries off raw fact scans.

## In-house collaboration on ClickHouse-class storage

Not every partnership justifies Snowflake Clean Rooms fees. Teams with existing ClickHouse clusters sometimes run **private collaboration projects**:

- Separate database per partner with row policies on `partner_id`
- Shared read-only role executing only approved query IDs
- Object storage ingress via short-lived credentials
- Suppression enforced in SQL views wrapping fact tables

Example view wrapping exports:

```sql
CREATE VIEW partner_campaign_summary AS
SELECT
    campaign_id,
    count() AS users
FROM collaboration_joined
WHERE partner_id = currentSetting('partner_id')
GROUP BY campaign_id
HAVING users >= 100;
```

You own the audit plumbing. Legal must still sign off. This pattern suits high-frequency operational metrics; the vendor clean room remains the system of record for contractual reporting when required.

## Tinybird after the clean room exports aggregates

Clean rooms produce **approved summary tables**: overlap counts, lift estimates, reach by segment. Product and ops teams want those numbers in dashboards and alerting, not quarterly CSV drops.

Tinybird ingests daily aggregate exports from S3 or streams smaller refresh batches via Kafka. Pipes publish HTTPS endpoints marketing tools call without JDBC access to the collaboration cluster.

```sql
NODE campaign_reach_by_partner
SQL >
    SELECT
        campaign_id,
        reach,
        conversions,
        measured_at
    FROM clean_room_exports
    WHERE partner_id = {{ String(partner_id, required=True) }}
      AND measured_at >= today() - 90
    ORDER BY measured_at DESC

TYPE endpoint
```

JWT **fixed_params** lock partner scope. **Service Data Sources** alert when today's export file never landed. [Build real-time APIs on ClickHouse](https://www.tinybird.co/blog/build-real-time-apis-clickhouse-tinybird) covers SQL-to-HTTP without custom glue services.

Canva processes 3.6 PB/month on Tinybird. SOC 2 Type II matters when aggregate exports feed customer-facing reporting UIs.

## Collaboration mistakes that burn trust

**Letting each analyst write free-form SQL.** One SELECT * away from a policy incident.

**Reusing salts across rooms.** Partner A's breach becomes Partner B's relinking risk.

**Confusing clean room with anonymization.** k-threshold aggregates can still be sensitive at small populations.

**No test vectors.** Zero overlap reports erode trust before anyone debugs hashing.

**Operational metrics only in the room.** Teams export unofficial copies because official path takes days.

**Permanent rooms.** Campaign ended; credentials did not.

## Choosing your collaboration stack

Use **vendor clean rooms** when contracts mandate them, both parties already sit in that cloud, and audit export is required. Use **in-house columnar projects** when you control both tokenized datasets and need daily operational endpoints. Use **Tinybird** to serve approved aggregates fast after either path produces summary tables.

Data clean rooms collaboration is joined measurement with enforced floors, not shared spreadsheets. Design queries, hashes, and exports before you design the press release.

## Frequently Asked Questions (FAQs)

### Is a clean room the same as a data warehouse share?

No. Shares can expose tables. Clean rooms restrict outputs to approved aggregates and log queries.

### Who pays for compute in vendor clean rooms?

Contracts vary. Define scan and egress costs before production campaigns.

### Can you run ML inside a clean room?

Some vendors support federated or templated ML. Most partnerships start with aggregate SQL only.

### What if overlap is always zero?

Validate hashing rules with test emails and devices both sides agree on before changing campaign logic.

### Do clean rooms replace CDPs?

No. CDPs collect and activate first-party data. Clean rooms measure overlap with partner data under policy.

### Where does Tinybird fit?

Downstream serving of approved aggregate exports via HTTP endpoints and monitoring, not inside the legal clean room boundary itself.

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