A flow that executes a single time and repeats only if the pipeline is fully refreshed. It's a common choice for a first full load ahead of a change feed, and that refresh becomes dangerous once the original files no longer exist.
Also called ONCE.
Read more: Databricks docs
In the Ultra Transcenders books
Each book explains Once flow in context, with comparison tables and the common traps.
Terms in this definition
- Flow
The unit of work inside a Lakeflow pipeline that takes data from a source, transforms it and lands it in a destination like a streaming table. Streaming flows either append or update, and
CREATE FLOWlets you declare a flow apart from the table it feeds. - Pipeline
Groups activities logically so that, together, they move and transform data, either one after another or side by side; found in both Azure Data Factory and Microsoft Fabric.
- FIRST
A DAX function available only inside visual calculations. It fetches the value at the start of one axis of the visual's matrix, which makes it handy for comparing each point with the first; its opposite is LAST.
- Full load
An approach where each run reloads all of the source data. It is easy to build and corrects itself, but becomes expensive for big tables and should never be used for dimensions whose surrogate keys are generated.
- Change feed
A log, in order, of changes made to blobs; point-in-time restore for block blobs depends on it.
Related terms
- AADRiskyUsers
A Log Analytics table listing the users that Microsoft Entra ID Protection flags as risky, with each user's risk level and state. It is populated once you export the RiskyUsers category through diagnostic settings.
- AADUserRiskEvents
A Log Analytics table recording the user risk detections raised by Microsoft Entra ID Protection. Data arrives once the UserRiskEvents category is exported through diagnostic settings.
- ABAC
An access-control approach in Unity Catalog where governed tags determine what a policy covers. A single policy set on a metastore, catalog, schema or table can therefore filter rows, mask columns, or grant or deny access across many objects at once.
- Access keys
Pair of 512-bit keys belonging to a storage account; every account SAS and service SAS is signed with one of them. Once both are regenerated, direct key access and all those SAS tokens stop working.
- Access mode
Set on each compute resource, this controls which people can attach and what data they reach. Dedicated (once called single user) belongs to a single user or group, standard (once called shared) keeps many users apart from each other, and Auto leaves the choice to the runtime.
- Access package
Bundle in entitlement management that groups apps, groups and sites together with request policies and an expiry. Access to the resources is withdrawn once an assignment expires.
- ACPI
A standard that lets a hypervisor tell a guest operating system about power and device events. AHV's
vm.rebootsends one of these events, and removing a vNIC finishes only once the guest answers the request. - acr purge
A container command, currently in preview, that runs as an ACR task either on demand or on a schedule. It removes tags matching a repository and tag regex once they pass a given age, can also clear untagged manifests, and anything it deletes is gone for good.