> ## 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.

# Data Catalog

> Auto-inventory every table and column across Zwiron connections — searchable, tagged, and always current.

The **Data Catalog** gives your team a unified view of all data assets connected to Zwiron. Every schema, table, and column discovered during [connection profiling](/concepts/connection-profiling) is indexed here with row counts, sizes, column types, and nullability — no manual entry required.

***

## How the catalog is populated

The catalog is built from connection profiles. When you run a profile on a connection, the agent connects read-only to your database, discovers all schemas and tables, inspects every column, and writes the results back. The catalog reflects the state of your database at the time of the last profile.

To refresh stale data, run a new profile on the connection.

<Info>Profiling runs through your agent — schema metadata never flows through Zwiron's cloud.</Info>

***

## Browsing assets

Go to **Catalog** in the sidebar.

### Sidebar tree

The left panel shows a source tree grouped by connection. Expand any connection to see its schemas. Clicking a schema filters the main list to that schema's tables.

Additional filters:

| Filter         | Options                             |
| -------------- | ----------------------------------- |
| **Type**       | `table`, `schema`, `column`         |
| **Connection** | Filter to one specific connection   |
| **Tags**       | Filter by any tag applied to assets |

### Search

The search bar performs full-text search across table names, column names, and schema names. Results update as you type.

### Asset list columns

| Column          | Description                                                  |
| --------------- | ------------------------------------------------------------ |
| **Name**        | Asset name                                                   |
| **Connection**  | Which connection it belongs to                               |
| **Rows**        | Row count at last profile                                    |
| **Size**        | On-disk size at last profile                                 |
| **Last synced** | When a Zwiron pipeline last moved data from or to this table |
| **Profiled**    | How long ago this connection was profiled                    |
| **Tags**        | Applied tags                                                 |

***

## Asset detail

Click any table to open its detail page.

### Overview

Displays the asset's qualified name (e.g. `production.public.orders`), connection, row count, size, profiled timestamp, and last sync time.

### Columns

A virtualized list of every column in the table. Each row shows:

| Field                   | Description                                           |
| ----------------------- | ----------------------------------------------------- |
| **#**                   | Ordinal position                                      |
| **Name**                | Column name                                           |
| **Type**                | SQL data type (e.g. `varchar`, `int8`, `timestamptz`) |
| **PK**                  | Present if the column is part of the primary key      |
| **NOT NULL / nullable** | Nullability constraint                                |

Click a column to apply **governance tags** to that column (for example, tag `email` as `Email` instead of labeling the whole table). Matching policies for the column’s tags appear in the same panel.

Use the inline search to filter columns by name or type.

### Stats

Column-level statistics collected during profiling:

* Null percentage
* Distinct value count
* Min / max / average (for numeric columns)
* Most common values

### Applicable policies

Open the **Policies** tab on the asset detail page for the full list of matching table and column policies (scrollable — safe when many policies apply). The Catalog peek panel only shows a one-line count that links here.

***

## Tags

Tags come from your **Governance → Tag Classifications** taxonomy. Apply them on tables (peek panel or Profile) or on individual columns (Columns tab).

### Add a tag

1. Open any table in the Catalog
2. Use the Tags picker (taxonomy search + optional classification filter)
3. Select a tag from the list

### Filter by tag

Click any tag chip in the asset list to filter to all assets with that tag.

### Remove a tag

Click **×** on any tag chip on an asset.

<Info>Define classifications and allowed tags under [Governance](/platform/governance). The Catalog is where you apply them to tables and columns.</Info>

***

## Deleting an asset

1. Open the asset detail page
2. Click the trash icon in the top-right corner
3. Confirm the deletion

<Warning>Deletion is permanent. If the underlying table still exists in the database, it will reappear the next time the connection is profiled.</Warning>

***

## Keeping the catalog current

The catalog reflects your database at the time of the last profile. Tables added after the last profile do not appear until a new profile runs.

**To trigger a profile:**

1. Go to **Connections**
2. Select the connection
3. Click **Profile**

***

## Permissions

| Role       | Access                         |
| ---------- | ------------------------------ |
| **Admin**  | Browse, tag, and delete assets |
| **Editor** | Browse and manage tags         |
| **Viewer** | Browse only                    |

***

## Related

* [Connection Profiling](/concepts/connection-profiling) — how catalog data is collected
* [Governance](/platform/governance) — structured classification tags
* [Data Quality](/platform/data-quality) — test rules on catalog tables