[
https://issues.apache.org/jira/browse/HIVE-26524?focusedWorklogId=813657&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-813657
]
ASF GitHub Bot logged work on HIVE-26524:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 30/Sep/22 10:46
Start Date: 30/Sep/22 10:46
Worklog Time Spent: 10m
Work Description: kasakrisz commented on code in PR #3588:
URL: https://github.com/apache/hive/pull/3588#discussion_r984464007
##########
ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/translator/ASTConverter.java:
##########
@@ -121,7 +127,87 @@ public static ASTNode convert(final RelNode relNode,
List<FieldSchema> resultSch
return c.convert();
}
+ // TOK_QUERY
+ // TOK_INSERT
+ // TOK_DESTINATION
+ // TOK_DIR
+ // TOK_TMP_FILE
+ // TOK_SELECT
+ // TOK_SELEXPR
+ // TOK_FUNCTION
+ // TOK_<type>
+ // TOK_NULL
+ // alias0
+ // ...
+ // TOK_SELEXPR
+ // TOK_FUNCTION
+ // TOK_<type>
+ // TOK_NULL
+ // aliasn
+ // TOK_LIMIT
+ // 0
+ // 0
+ public static ASTNode emptyPlan(RelDataType dataType) {
+ if (dataType.getFieldCount() == 0) {
+ throw new IllegalArgumentException("Schema is empty.");
+ }
+
+ ASTBuilder select = ASTBuilder.construct(HiveParser.TOK_SELECT,
"TOK_SELECT");
+ for (int i = 0; i < dataType.getFieldCount(); ++i) {
+ RelDataTypeField fieldType = dataType.getFieldList().get(i);
+ if (fieldType.getValue().getSqlTypeName() == SqlTypeName.NULL) {
+ select.add(ASTBuilder.selectExpr(
+ ASTBuilder.construct(HiveParser.TOK_NULL, "TOK_NULL").node(),
+ fieldType.getName()));
+ } else {
+ ASTNode typeNode = createCast(fieldType);
+ select.add(ASTBuilder.selectExpr(
+ ASTBuilder.construct(HiveParser.TOK_FUNCTION, "TOK_FUNCTION")
+ .add(typeNode)
+ .add(ASTBuilder.construct(HiveParser.TOK_NULL,
"TOK_NULL").node()).node(),
+ fieldType.getName()));
+ }
+ }
+
+ ASTNode insert = ASTBuilder.
+ construct(HiveParser.TOK_INSERT, "TOK_INSERT").
+ add(ASTBuilder.destNode()).
+ add(select).
+ add(ASTBuilder.limit(0, 0)).
+ node();
+
+ return ASTBuilder.
+ construct(HiveParser.TOK_QUERY, "TOK_QUERY").
+ add(insert).
+ node();
+ }
+
+ private static ASTNode createCast(RelDataTypeField fieldType) {
+ HiveToken ht = TypeConverter.hiveToken(fieldType.getType());
+ ASTNode typeNode;
+ if (ht == null) {
+ typeNode = ASTBuilder.construct(
+ HiveParser.Identifier,
fieldType.getType().getSqlTypeName().getName().toLowerCase()).node();
+ } else {
+ ASTBuilder typeNodeBuilder = ASTBuilder.construct(ht.type, ht.text);
+ if (ht.args != null) {
+ for (String castArg : ht.args) {
+ typeNodeBuilder.add(HiveParser.Identifier, castArg);
+ }
+ }
+ typeNode = typeNodeBuilder.node();
+ }
+ return typeNode;
+ }
+
private ASTNode convert() throws CalciteSemanticException {
+ if (root instanceof HiveValues) {
+ HiveValues values = (HiveValues) root;
+ if (isEmpty(values)) {
+ select = values;
+ return emptyPlan(values.getRowType());
+ }
Review Comment:
No it can't. Theoretically non-empty `HiveValues` are not created currently.
How about throwing an exception? My problem with assertions is that it does
not evaluates in production environments and I had some difficulties to repro
issues locally from q test: so the q test failed with assertion error but
something different exception was thrown from a different place in prod.
Issue Time Tracking
-------------------
Worklog Id: (was: 813657)
Time Spent: 4h 40m (was: 4.5h)
> Use Calcite to remove sections of a query plan known never produces rows
> ------------------------------------------------------------------------
>
> Key: HIVE-26524
> URL: https://issues.apache.org/jira/browse/HIVE-26524
> Project: Hive
> Issue Type: Improvement
> Components: CBO
> Reporter: Krisztian Kasa
> Assignee: Krisztian Kasa
> Priority: Major
> Labels: pull-request-available
> Time Spent: 4h 40m
> Remaining Estimate: 0h
>
> Calcite has a set of rules to remove sections of a query plan known never
> produces any rows. In some cases the whole plan can be removed. Such plans
> are represented with a single {{Values}} operators with no tuples. ex.:
> {code:java}
> select y + 1 from (select a1 y, b1 z from t1 where b1 > 10) q WHERE 1=0
> {code}
> {code:java}
> HiveValues(tuples=[[]])
> {code}
> Other cases when plan has outer join or set operators some branches can be
> replaced with empty values moving forward in some cases the join/set operator
> can be removed
> {code:java}
> select a2, b2 from t2 where 1=0
> union
> select a1, b1 from t1
> {code}
> {code:java}
> HiveAggregate(group=[{0, 1}])
> HiveTableScan(table=[[default, t1]], table:alias=[t1])
> {code}
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