With the Replace update method, this Dataflow Gen2 option keeps the existing destination table and swaps only its contents, so any relationships and measures survive. Warehouse destinations offer nothing else; the Dynamic schema alternative drops and rebuilds the table.
Read more: Microsoft Learn
In the Ultra Transcenders books
Each book explains Fixed schema in context, with comparison tables and the common traps.
Terms in this definition
- CRUD
Shorthand for create, read, update and delete, the four basic things you do with data. Data-plane roles in Azure Cosmos DB, for instance, authorise those operations on items.
- Dataflow Gen2
A visual, low-code Microsoft Fabric item for preparing data, based on Power Query. It links to data sources, transforms the data and writes the output to targets like a lakehouse or a warehouse.
- Event
Table in Log Analytics where entries from Windows event logs are kept.
- Warehouse
Fabric item offering complete T-SQL support (DML, DDL, multi-table transactions) over Delta tables held in OneLake; lakehouse SQL analytics endpoints, by contrast, are read-only.
- Dynamic schema
If the shape of incoming data changes, this Dataflow Gen2 option throws away the target table and builds it afresh, which means any relationships or measures layered on top may disappear. It is offered only when Replace is the update method; choosing Fixed schema instead preserves the table and swaps just its rows.
Related terms
- Azure Table Storage
Holds structured NoSQL records without a fixed schema, using keys and attributes; think device details, contact lists or user records. It now sits within the Azure Cosmos DB family, where Azure Cosmos DB for Table is the premium step up.