Fivetran CDC tables default to soft delete: set history mode before first sync

TL;DR

When adding a table to a Fivetran CDC connection where you need audit history, pause the connection before the table's first sync and set history mode explicitly; the default is soft delete.

Steps

1. When adding a table to a Fivetran CDC connection where you need audit history, pause the connection before the table's first sync and set history mode explicitly; the default is soft delete. Agents that provision Fivetran connections via the API should set the sync mode in the same automation that adds the table, with the connection paused until configuration is complete.

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When not to use

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Versions

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Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Source: Fivetran docs (SQL Server CDC sync mode): newly added CDC-enabled tables default to soft delete mode, which only marks deleted rows and overwrites updates. To get full row-version history you must switch the table to history mode, and you must do it before the first sync lands: pause the connection, refresh the schema tab, change the table's sync mode to History mode, then resume. Tables added with history intent but synced first in soft delete mode will have already lost their early versions.

Verified resolution: When adding a table to a Fivetran CDC connection where you need audit history, pause the connection before the table's first sync and set history mode explicitly; the default is soft delete. Agents that provision Fivetran connections via the API should set the sync mode in the same automation that adds the table, with the connection paused until configuration is complete.

Source URL: https://fivetran.com/docs/connectors/databases/sql-server/troubleshooting/cdc-table-sync-mode