> ## Documentation Index
> Fetch the complete documentation index at: https://docs.zwiron.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Match advanced settings

> Blocking mode, scoring mode, survivorship, overlap, lookup, and write-back targets for Match projects.

## Overview

Advanced Match settings refine how records are blocked, scored, and written back. You can open them:

* On **New project** / **Edit**, via **Show advanced scoring & write-back**
* On the project page, via **Advanced**

<Note>
  Change advanced settings carefully. Verify with a **Full run** or **Run delta** on representative data before **Write back approved** to a production table.
</Note>

For create / run / delete procedures, see [Match projects](/match/projects).

***

## Tightness presets

On create / edit, tightness presets apply coordinated defaults:

| Preset | Intent |
| - | - |
| **Tight** | Fewer false positives — higher thresholds, exact blocking |
| **Balanced** | Middle ground |
| **Loose** | Catch more candidates — phonetic blocking, lower minimum score |

Presets are starting points. Override individual fields afterward as needed.

***

## Blocking

| Setting | Values / purpose |
| - | - |
| **Blocking keys** | Required. Columns that form a block |
| **Blocking mode** | **Exact**, **Phonetic** (Soundex), or **Fuzzy** (prefix-style) |

Use multiple blocking keys when a single field is often missing or mistyped.

***

## Scoring and thresholds

| Setting | Values / purpose |
| - | - |
| **Compare fields** | Columns scored inside a block |
| **Scoring mode** | **Hybrid**, **Rules only**, or **Embedding only** |
| **Min score** | Drop pairs below this score (0–1) |
| **Auto-approve high-confidence groups** | Checkbox; when on, shows **Auto-approve threshold** |
| **Auto-approve threshold** | Score cutoff (0–1) used with auto-approve |

<Note>
  Confirm steward review expectations for your organization before relying on auto-approve. Review remains available on the run results pages.
</Note>

***

## Survivorship and destination

| Setting | Values / purpose |
| - | - |
| **Survivorship** | **Longest non-empty**, **First populated**, **Source priority**, or **Most recent** |
| **Timestamp field** | Column used with **Most recent** survivorship |
| **Source field** | Column naming the source system |
| **Source priority** | Ordered source values when using **Source priority** |
| **Golden table** | Destination table for write-back (placeholder example in UI: `public.customers_golden`) |
| **Destination connection** | Connection used for golden upsert (defaults to source when unset) |

See [Golden records and write-back](/match/write-back).

***

## Overlap and lookup

| Setting | Purpose |
| - | - |
| **Overlap table** | Optional second table for overlap-style matching |
| **Lookup** / generate index | Build a blocking index for **Delta** / lookup-style incremental matching (**Generate lookup** on the project page) |
| **Lookup min score** | Minimum score for lookup matching |
| **Lookup methods** | Methods used for lookup (for example blocking) |

Use **Delta** on the Projects list, or check **Delta** and click **Run delta** on the project page, when lookup is configured.

***

## Other advanced options

Depending on the **Advanced scoring & write-back** section, you may also configure:

* Field weights / score matrix
* Input normalization and cleanse options (email, phone, name, org)
* Address fields, country field, address verification
* Max cluster size and aggressive split
* Post-match rules

Confirm each control’s in-product help text for the exact behavior of your build.

***

## Related articles

* [Match overview](/match/overview)
* [Match projects](/match/projects)
* [Reviewing Match results](/match/review)
* [Golden records and write-back](/match/write-back)


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