UnresolvedRelation.isStreaming + STREAM SQL clause

Author: jaceklaskowski

docs/logical-operators/UnresolvedRelation.md

@@ -14,7 +14,7 @@ title: UnresolvedRelation
 
 * <span id="multipartIdentifier"> Multi-part identifier
 * <span id="options"> Options
-* <span id="isStreaming"> [isStreaming](LogicalPlan.md#isStreaming) flag (default:`false`)
+* [isStreaming](#isStreaming) flag
 
 `UnresolvedRelation` is created (possibly indirectly using [apply](#apply) factory) when:
 
@@ -27,6 +27,19 @@ title: UnresolvedRelation
 * `DataStreamReader.table` ([Spark Structured Streaming]({{ book.structured_streaming }}/DataStreamReader#table)) operator is used
 * [table](../catalyst-dsl/index.md#table) ([Catalyst DSL](../catalyst-dsl/index.md)) operator is used
 
+### isStreaming Flag { #isStreaming }
+
+`UnresolvedRelation` is given [isStreaming](LogicalPlan.md#isStreaming) flag when [created](#creating-instance).
+
+`isStreaming` can be specified with [apply](#apply) factory method.
+
+`isStreaming` is disabled (`false`) by default.
+
+`isStreaming` is enabled (`true`) when:
+
+* `AstBuilder` is requested to [parse STREAM relation clause](../sql/AstBuilder.md#visitStreamTableName)
+* `DataStreamReader.table` ([Spark Structured Streaming]({{ book.structured_streaming }}/DataStreamReader/#table)) operator is used
+
 ## Creating UnresolvedRelation { #apply }
 
 ```scala
@@ -49,7 +62,7 @@ apply(
 
 ## Name { #name }
 
-??? note "Signature"
+??? note "NamedRelation"
 
  ```scala
  name: String
@@ -69,7 +82,7 @@ tableName: String
 
 ## resolved
 
-??? note "Signature"
+??? note "LogicalPlan"
 
  ```scala
  resolved: Boolean
@@ -81,7 +94,7 @@ tableName: String
 
 ## nodePatterns { #nodePatterns }
 
-??? note "Signature"
+??? note "TreeNode"
 
  ```scala
  nodePatterns: Seq[TreePattern]

docs/sql/AstBuilder.md

@@ -698,8 +698,8 @@ Creates an [UnresolvedRelation](../logical-operators/UnresolvedRelation.md) logi
 
 ```antlr
 streamRelationPrimary
- : STREAM multipartIdentifier [WITH options]? (AS? strictIdentifier identifierList?)? #streamTableName
- | STREAM '(' multipartIdentifier ')' [WITH options]? (AS? strictIdentifier identifierList?)? #streamTableName
+ : STREAM multipartIdentifier [WITH options]? [WATERMARK colName DELAY OF delay] (AS? strictIdentifier identifierList?)? #streamTableName
+ | STREAM '(' multipartIdentifier ')' [WITH options]? [WATERMARK colName DELAY OF delay] (AS? strictIdentifier identifierList?)? #streamTableName
  ;
 ```
 
@@ -1149,6 +1149,25 @@ With no `namedArgumentExpression` used, `extractNamedArgument` creates an [Expre
 
 * `AstBuilder` is requested to [visitFunctionCall](#visitFunctionCall) and [visitTableValuedFunction](#visitTableValuedFunction)
 
+## createUnresolvedRelation { #createUnresolvedRelation }
+
+```scala
+createUnresolvedRelation(
+ ctx: IdentifierReferenceContext,
+ optionsClause: Option[OptionsClauseContext] = None,
+ writePrivileges: Seq[TableWritePrivilege] = Nil): LogicalPlan // (1)!
+createUnresolvedRelation(
+ ctx: ParserRuleContext,
+ ident: Seq[String],
+ optionsClause: Option[OptionsClauseContext],
+ writePrivileges: Seq[TableWritePrivilege],
+ isStreaming: Boolean): UnresolvedRelation
+```
+
+1. Creates an [UnresolvedRelation](../logical-operators/UnresolvedRelation.md) logical operator with [isStreaming](../logical-operators/UnresolvedRelation.md#isStreaming) flag disabled (`false`)
+
+`createUnresolvedRelation` creates an [UnresolvedRelation](../logical-operators/UnresolvedRelation.md) logical operator.
+
 ## Create UnresolvedTable Logical Operator { #createUnresolvedTable }
 
 ```scala