Glossary Entry

Fivetran for the lakehouse: loading Iceberg tables, and Fivetran vs Airbyte

Fivetran is a managed ELT service that copies data from SaaS apps and databases into warehouses and lakes. See how it loads Iceberg and compares to Airbyte.

Written by Alex Merced

Fivetran is a managed data integration service. It provides prebuilt connectors that extract data from SaaS applications (Salesforce, Zendesk, Stripe), databases (PostgreSQL, MySQL, SQL Server, Oracle), and files, then load it into a destination such as a cloud warehouse or a data lakehouse. Fivetran maintains the connectors, so API changes and source schema changes are its problem rather than yours. In June 2026 Fivetran completed its merger with dbt Labs, the company behind dbt.

Extract and load, then transform

Fivetran follows the ELT pattern: it lands source data in the destination with a schema close to the source, and transformation happens afterward in the destination engine, typically with dbt. Fivetran’s job is the E and the L.

Schema drift

Source systems change. Columns get added, tables get dropped, types change. Fivetran detects these changes on sync and applies schema changes in the destination according to the connection’s schema change settings, for example adding a new customer_tier column instead of failing the sync. You can also choose to block new tables or columns until someone approves them.

Change data capture and incremental syncs

After the initial historical sync, Fivetran syncs incrementally. For databases it uses log-based change data capture where available (for example PostgreSQL logical replication or the MySQL binlog), reading inserts, updates, and deletes from the log instead of rescanning tables. This keeps load on the production database low. Some sources fall back to cursor or full-table methods.

Normalized output and safe retries

For API sources, Fivetran publishes a documented schema per connector and unpacks nested objects into related tables where the connector’s schema calls for it. Syncs track cursors so that a failed sync can be retried without creating duplicate rows.

Loading Iceberg with Fivetran

Fivetran’s Managed Data Lake Service writes to your own object storage (Amazon S3, ADLS, or Google Cloud Storage). It always creates Apache Iceberg metadata for the tables it maintains and can optionally create Delta Lake metadata too. Tables are registered in the Fivetran Catalog, which Fivetran describes as a managed implementation of Apache Polaris that works with any Iceberg REST catalog client, or in a cloud catalog such as AWS Glue, OneLake, or BigLake Metastore. From there, Dremio, Trino, Spark, or Snowflake can query the same tables, and these become the bronze layer of a medallion architecture.

Fivetran vs Airbyte for loading Iceberg

FivetranAirbyte
ModelFully managed SaaSOpen-source platform (ELv2) you self-host, plus Airbyte Cloud
Iceberg destinationManaged Data Lake Service on S3, ADLS, or GCSS3 Data Lake destination on S3 or S3-compatible storage
CatalogsFivetran Catalog (Polaris based), Glue, OneLake, BigLake; Unity and Snowflake integrationsREST, Glue, Nessie, Polaris
Table maintenanceFivetran manages the lake tablesWrites data; you run compaction and snapshot expiry
Custom connectorsConnector SDKConnector Builder and CDK; large community catalog
PricingUsage based on monthly active rowsFree to self-host (open-source edition); Airbyte Cloud is paid

Choose Fivetran when you want the least operational work and your sources are covered by its connectors. Choose Airbyte when you need to self-host, need a long-tail or custom connector, or want to control cost by running it yourself.

Learn More

To learn more about the Data Lakehouse, read The Lakehouse Built for Everyone by Alex Merced. You can find this and other books by Alex Merced at books.alexmerced.com.

Work with Alex