Code is not generated for LocalTableScanExec although proper situations.
If a LocalTableScanExec plan has the direct parent plan which supports WholeStageCodegen,
the LocalTableScanExec plan also should be within a WholeStageCodegen domain.
But code is not generated for LocalTableScanExec and InputAdapter is inserted for now.
```
val df1 = spark.createDataset(1 to 10).toDF
val df2 = spark.createDataset(1 to 10).toDF
val df3 = df1.join(df2, df1("value") === df2("value"))
df3.explain(true)
...
== Physical Plan ==
*(1) BroadcastHashJoin [value#1], [value#6], Inner, BuildRight
:- LocalTableScan [value#1] // LocalTableScanExec is not within a WholeStageCodegen domain
+- BroadcastExchange HashedRelationBroadcastMode(List(cast(input[0, int, false] as bigint)))
+- LocalTableScan [value#6]
```
```
scala> df3.queryExecution.executedPlan.children.head.children.head.getClass
res4: Class[_ <: org.apache.spark.sql.execution.SparkPlan] = class org.apache.spark.sql.execution.InputAdapter
```
For the current implementation of LocalTableScanExec, codegen is enabled in case `parent` is not null
but `parent` is set in `consume`, which is called after `insertInputAdapter` so it doesn't work as intended.
After applying this cnahge, we can get following plan, which means LocalTableScanExec is within a WholeStageCodegen domain.
```
== Physical Plan ==
*(1) BroadcastHashJoin [value#63], [value#68], Inner, BuildRight
:- *(1) LocalTableScan [value#63]
+- BroadcastExchange HashedRelationBroadcastMode(List(cast(input[0, int, false] as bigint)))
+- LocalTableScan [value#68]
## How was this patch tested?
New test cases are added into WholeStageCodegenSuite.
Closes#25260 from sarutak/localtablescan-improvement.
Authored-by: Kousuke Saruta <sarutak@oss.nttdata.com>
Signed-off-by: Takeshi Yamamuro <yamamuro@apache.org>
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