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https://issues.apache.org/jira/browse/DRILL-7503?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17007025#comment-17007025
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ASF GitHub Bot commented on DRILL-7503:
---------------------------------------
ihuzenko commented on pull request #1944: DRILL-7503: Refactor the project
operator
URL: https://github.com/apache/drill/pull/1944#discussion_r362452176
##########
File path:
exec/java-exec/src/main/java/org/apache/drill/exec/physical/impl/project/ProjectMemoryManager.java
##########
@@ -42,307 +44,310 @@
import java.util.Map;
/**
- *
- * ProjectMemoryManager(PMM) is used to estimate the size of rows produced by
ProjectRecordBatch.
- * The PMM works as follows:
- *
- * Setup phase: As and when ProjectRecordBatch creates or transfers a field,
it registers the field with PMM.
- * If the field is a variable width field, PMM records the expression that
produces the variable
- * width field. The expression is a tree of LogicalExpressions. The PMM walks
this tree of LogicalExpressions
- * to produce a tree of OutputWidthExpressions. The widths of Fixed width
fields are just accumulated into a single
- * total. Note: The PMM, currently, cannot handle new complex fields, it just
uses a hard-coded estimate for such fields.
- *
- *
- * Execution phase: Just before a batch is processed by Project, the PMM walks
the tree of OutputWidthExpressions
- * and converts them to FixedWidthExpressions. It uses the RecordBatchSizer
and the function annotations to do this conversion.
- * See OutputWidthVisitor for details.
+ * ProjectMemoryManager(PMM) is used to estimate the size of rows produced by
+ * ProjectRecordBatch. The PMM works as follows:
+ * <p>
+ * Setup phase: As and when ProjectRecordBatch creates or transfers a field, it
+ * registers the field with PMM. If the field is a variable width field, PMM
Review comment:
```suggestion
* registers the field with PMM. If the field is a variable-width field, PMM
```
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> Refactor project operator
> -------------------------
>
> Key: DRILL-7503
> URL: https://issues.apache.org/jira/browse/DRILL-7503
> Project: Apache Drill
> Issue Type: Improvement
> Affects Versions: 1.17.0
> Reporter: Paul Rogers
> Assignee: Paul Rogers
> Priority: Minor
> Fix For: 1.18.0
>
>
> Work on another ticket revealed that the Project operator ("record batch")
> has grown quite complex. The setup phase lives in the operator as one huge
> function. The function combines the "logical" tasks of working out the
> projection expressions and types, the code gen for those expressions, and the
> physical setup of vectors.
> The refactoring breaks up the logic so that it is easier to focus on the
> specific bits of interest.
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