andygrove commented on code in PR #7952:
URL: https://github.com/apache/arrow-datafusion/pull/7952#discussion_r1375268473
##########
docs/source/library-user-guide/building-logical-plans.md:
##########
@@ -19,4 +19,135 @@
# Building Logical Plans
-Coming Soon
+A logical plan is a structured representation of a database query that
describes the high-level operations and
+transformations needed to retrieve data from a database or data source. It
abstracts away specific implementation
+details and focuses on the logical flow of the query, including operations
like filtering, sorting, and joining tables.
+
+This logical plan serves as an intermediate step before generating an
optimized physical execution plan.
+
+## Building Logical Plans Manually
+
+DataFusion's [LogicalPlan] is an enum containing variants representing all the
supported operators, and also
+contains an `Extension` variant that allows projects building on DataFusion to
add custom logical operators.
+
+It is possible to create logical plans by directly creating instances of the
[LogicalPlan] enum as follows, but is is
+much easier to use the [LogicalPlanBuilder], which is described in the next
section.
+
+Here is an example of building a logical plan directly:
+
+<!-- source for this example is in
datafusion_docs::library_logical_plan::plan_1 -->
+
+```rust
+// create a logical table source
+let schema = Schema::new(vec![
+ Field::new("id", DataType::Int32, true),
+ Field::new("name", DataType::Utf8, true),
+]);
+let table_source = LogicalTableSource::new(SchemaRef::new(schema));
+
+// create a TableScan plan
+let projection = None; // optional projection
+let filters = vec![]; // optional filters to push down
+let fetch = None; // optional LIMIT
+let table_scan = LogicalPlan::TableScan(TableScan::try_new(
+ "person",
+ Arc::new(table_source),
+ projection,
+ filters,
+ fetch,
+)?);
+
+// create a Filter plan that wraps the TableScan
+let filter_expr = col("id").gt(lit(500));
+let plan = LogicalPlan::Filter(Filter::try_new(filter_expr,
Arc::new(table_scan))?);
+
+// print the plan
Review Comment:
I'll address this one in a future PR once I have the initial automation in
place - I need to implement some code so that I have more control over which
code from the test makes it into the docs
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