Update docs

Author: gabotechs

docs/source/user-guide/channel-resolver.md

@@ -43,7 +43,7 @@ async fn main() {
     let state = SessionStateBuilder::new()
         // these two are mandatory.
         .with_distributed_worker_resolver(todo!())
-        .with_physical_optimizer_rule(Arc::new(DistributedPhysicalOptimizerRule))
+        .with_distributed_physical_optimizer_rules()
         // the CustomChannelResolver needs to be passed here once...
         .with_distributed_channel_resolver(channel_resolver.clone())
         .build();

docs/source/user-guide/concepts.md

@@ -24,14 +24,6 @@ You'll see these concepts mentioned extensively across the documentation and the
 
 Some other more tangible concepts are the structs and traits exposed publicly, the most important are:
 
-## [DistributedPhysicalOptimizerRule](https://github.com/datafusion-contrib/datafusion-distributed/blob/main/src/distributed_planner/distributed_physical_optimizer_rule.rs)
-
-A physical optimizer rule that transforms single-node DataFusion query plans into distributed query plans. It reads
-a fully formed physical plan and injects the appropriate nodes to execute the query in a distributed fashion.
-
-It builds the distributed plan from bottom to top, injecting network boundaries at appropriate locations based on
-the nodes present in the original plan.
-
 ## [Worker](https://github.com/datafusion-contrib/datafusion-distributed/blob/main/src/flight_service/worker.rs)
 
 Arrow Flight server implementation that integrates with the Tonic ecosystem and listens to serialized plans that get
@@ -70,3 +62,12 @@ data. If you are on the task with index 2, you might want to return the last 1/3
 
 Optional extension trait that allows to customize how connections are established to workers. Given one of the
 URLs returned by the `WorkerResolver`, it builds an Arrow Flight client ready for serving queries.
+
+## [NetworkBoundaryPlaceholder](https://github.com/datafusion-contrib/datafusion-distributed/blob/main/src/distributed_planner/network_boundary_placeholder.rs)
+
+A custom ExecutionPlan implementation that acts as a placeholder for the distributed planner to place network boundaries
+that spawn the specified amount of tasks.
+
+Users can create their own physical optimizer rules and place them before this project's ApplyNetworkBoundaries rule
+in order to customize their distributed plan.
+

docs/source/user-guide/getting-started.md

@@ -49,7 +49,7 @@ impl WorkerResolver for LocalhostWorkerResolver {
 }
 ```
 
-Register both the `WorkerResolver` implementation and the `DistributedPhysicalOptimizerRule` in DataFusion's
+Register both the `WorkerResolver` implementation and the distributed physical optimization rules in DataFusion's
 `SessionStateBuilder` to enable distributed query planning:
 
 ```rs
@@ -59,7 +59,7 @@ let localhost_worker_resolver = LocalhostWorkerResolver {
 
 let state = SessionStateBuilder::new()
     .with_distributed_worker_resolver(localhost_worker_resolver)
-    .with_physical_optimizer_rule(Arc::new(DistributedPhysicalOptimizerRule))
+    .with_distributed_physical_optimizer_rules()
     .build();
 
 let ctx = SessionContext::from(state);

docs/source/user-guide/worker-resolver.md

@@ -24,7 +24,7 @@ impl WorkerResolver for CustomWorkerResolver {
 async fn main() {
     let state = SessionStateBuilder::new()
         .with_distributed_worker_resolver(CustomWorkerResolver)
-        .with_physical_optimizer_rule(Arc::new(DistributedPhysicalOptimizerRule))
+        .with_distributed_physical_optimizer_rules()
         .build();
 }
 ```

src/distributed_planner/distributed_config.rs

@@ -118,8 +118,8 @@ impl ConfigExtension for DistributedConfig {
 // FIXME: Ideally, both ChannelResolverExtension and TaskEstimators would be passed as
 //  extensions in SessionConfig's AnyMap instead of the ConfigOptions. However, we need
 //  to pass this as ConfigOptions as we need these two fields to be present during
-//  planning in the DistributedPhysicalOptimizerRule, and the signature of the optimize()
-//  method there accepts a ConfigOptions instead of a SessionConfig.
+//  distributed planning, and the signature of the optimize()  method there accepts a
+//  ConfigOptions instead of a SessionConfig.
 //  The following PR addresses this: https://github.com/apache/datafusion/pull/18168
 //  but it still has not been accepted or merged.
 //  Because of this, all the boilerplate trait implementations below are needed.