Related guide: dv-link.

A link hub source connects one catalog DV_SOURCE feed to the link table. It answers: from this relationship source table, which columns identify each participating hub?

Hop generates one link update pipeline per hub source entry on the link’s Hub sources tab.

When you need this dialog

Open it from the link editor → Hub sources tab → select a source row → Edit hub source mappings…

You need at least one hub source for every Hop-managed link. Check model reports an error when hub sources are missing.

Data Vault Source

Select the catalog DV_SOURCE that supplies relationship rows — typically a bridge, junction, or fact table containing foreign keys to the participating hubs (e.g. order_line with order_id and product_id).

This is a catalog feed name, not a raw database connection. Configure the physical table, field list, and record source indicator in the Data Catalog perspective before mapping.

Hub key field mappings

For each participating hub listed on the link’s Options tab, add one hub mapping row and click Edit mappings to open the per-hub detail dialog.

Business key mappings (required)

Map each hub business key to a column in this source:

Hub business key field Source field name

Column on the hub definition (e.g. order_id)

Column in the link source (e.g. order_id or cust_order_fk)

Rules:

  • Include every business key on the hub, in the same order as on the hub’s Keys tab.

  • Composite hubs need one mapping row per business key column.

  • Mappings are per source — the same hub can use different column names in different feeds.

  • If names differ between hub and link source (very common), map explicitly; do not assume the loader will guess.

Example: hub_customer uses business key customer_id, but the order header source has cust_fk. Map customer_id → cust_fk.

Driving key mappings (when applicable)

If the link defines driving keys on its Driving keys tab, map each driving key to a source column in the same per-hub dialog:

Driving key Source field name

Target driving key name (e.g. FROM_LOCATION_HK)

Source column supplying that value

Driving keys disambiguate when the same hub appears multiple times in one link.

Step-by-step workflow

  1. On the link Options tab, list all participating hubs (at least two).

  2. On Hub sources, add a row and pick the catalog DV_SOURCE.

  3. Click Edit hub source mappings…

  4. Click Add hub mapping for each participating hub (or select an existing row and Edit mappings).

  5. In the hub key field dialog, fill business key → source column for every hub key.

  6. Add driving key → source column rows when the link uses driving keys.

  7. Confirm with OK on each dialog.

Repeat steps 2–7 for additional catalog feeds (multi-source links).

What the pipeline reads

For the selected source, the generated SQL selects only:

  • Mapped business key columns (per hub)

  • Mapped driving key columns (when configured)

  • The record source indicator (static value or indicator column from the catalog source)

Those values are hashed into hub keys, then into the link hash key. Unmapped columns are ignored for link loading.

A link can have several hub source rows — one per catalog feed that supplies relationships. Each feed gets its own pipeline (link-<table>-<source>). Use Record source group on Data Vault Update when you want to load only selected feeds in a run.

Validation

Check model verifies:

  • Every hub source has a catalog source name

  • Mapped source columns exist in the catalog field list

  • Business key fields exist on the referenced hub

  • Source and hub business key types are compatible (when detailed type checking is enabled)

Fix catalog field lists and mappings before running updates.

Tips

  • Define and load hubs first; link pipelines hash business keys the same way hub pipelines do.

  • One hub mapping row per participating hub — missing a hub causes pipeline generation to fail.

  • Column names in relationship tables often differ from hub staging tables; explicit mappings avoid extra SQL views.

  • The record source value comes from the catalog DV_SOURCE (indicator or indicator field), not from this mapping dialog.