[SDP] StreamingFlow.mustBeAppend flag (ignored)

Author: jaceklaskowski

docs/declarative-pipelines/AppendOnceFlow.md

@@ -2,7 +2,7 @@
 
 `AppendOnceFlow` is a [ResolvedFlow](ResolvedFlow.md) with [once](Flow.md#once) enabled.
 
-`AppendOnceFlow` is [created](#creating-instance) for a [UnresolvedFlow](UnresolvedFlow.md) with [once](UnresolvedFlow.md#once) flag enabled.
+`AppendOnceFlow` is [created](#creating-instance) for an [UnresolvedFlow](UnresolvedFlow.md) with [once](UnresolvedFlow.md#once) flag enabled.
 
 ## Creating Instance
 

docs/declarative-pipelines/StreamingFlow.md

@@ -2,16 +2,33 @@
 
 `StreamingFlow` is a [ResolvedFlow](ResolvedFlow.md) that may or may not be [append](#mustBeAppend).
 
-`StreamingFlow` is planned for execution as [StreamingTableWrite](StreamingTableWrite.md) by [FlowPlanner](FlowPlanner.md#plan).
+`StreamingFlow` is [planned for execution](FlowPlanner.md#plan) as [StreamingTableWrite](StreamingTableWrite.md) (assuming that the [Output](DataflowGraph.md#output) of [this flow](#flow)'s [destination](ResolutionCompletedFlow.md#destinationIdentifier) is a [Table](Table.md)).
 
 ## Creating Instance
 
 `StreamingFlow` takes the following to be created:
 
-* <span id="flow"> [UnresolvedFlow](UnresolvedFlow.md)
-* <span id="funcResult"> `FlowFunctionResult`
-* <span id="mustBeAppend"> `mustBeAppend` flag (default: `false`)
+* <span id="flow"> [UnresolvedFlow](ResolutionCompletedFlow.md#flow)
+* <span id="funcResult"> [FlowFunctionResult](ResolutionCompletedFlow.md#funcResult)
+* [mustBeAppend](#mustBeAppend) flag
 
 `StreamingFlow` is created when:
 
 * `FlowResolver` is requested to [convertResolvedToTypedFlow](FlowResolver.md#convertResolvedToTypedFlow) (for [UnresolvedFlow](UnresolvedFlow.md)s with their results being streaming dataframes)
+
+### mustBeAppend Flag { #mustBeAppend }
+
+```scala
+mustBeAppend: Boolean
+```
+
+`StreamingFlow` is given `mustBeAppend` flag when [created](#creating-instance).
+
+Default: `false`
+
+The value of `mustBeAppend` flag is based on whether there are more than one flow to [this flow](#flow)'s [destination](UnresolvedFlow.md#destinationIdentifier) in a dataflow graph or not.
+
+When enabled (`true`), [this UnresolvedFlow](#flow) is planned for execution with the `Append` output mode (as the other flows will then get their results overwritten).
+
+!!! note "StreamingTableWrite ignores mustBeAppend"
+    `StreamingFlow` is planned for execution as [StreamingTableWrite](StreamingTableWrite.md) with no execution differences based on the `mustBeAppend` flag.