[GitHub] [ignite] gvvinblade commented on a change in pull request #7979: IGNITE-12620 Calcite integration. Index Nested Loop Join/Hash Join

[GitBox <gi...@apache.org>]

gvvinblade commented on a change in pull request #7979:
URL: https://github.com/apache/ignite/pull/7979#discussion_r454440511



##########
File path: modules/calcite/src/main/java/org/apache/ignite/internal/processors/query/calcite/rule/logical/LogicalOrToUnionRule.java
##########
@@ -86,22 +83,14 @@ private LogicalOrToUnionRule(Class<LogicalFilter> clazz, String desc) {
      * @return UnionAll expression.
      */
     private RelNode createUnionAll(RelOptCluster cluster, RelNode input, RexNode op1, RexNode op2) {
-        final RelBuilder builder = relBuilderFactory.create(cluster, null);
-        final RexBuilder rexBuilder = cluster.getRexBuilder();
+        RelBuilder relBldr = relBuilderFactory.create(cluster, null);
 
-        builder.push(input).filter(op1);
-        builder.push(input).filter(
-            builder.and(op2,
-                // LNNVL is used here. We must treat 'null' values as valid.
-                rexBuilder.makeCall(op1.getType(), SqlStdOperatorTable.CASE,
-                    ImmutableList.of(
-                        rexBuilder.makeCall(SqlStdOperatorTable.IS_NOT_NULL, op1),
-                        RexUtil.not(op1),
-                        rexBuilder.makeLiteral(true))
-                )
-            )
-        );
-
-        return builder.union(true).build();
+        return relBldr
+            .push(input).filter(op1)
+            .push(input).filter(
+                relBldr.and(op2,
+                    relBldr.or(relBldr.isNull(op1), relBldr.not(op1))))

Review comment:
       The only reason is that OR can be simplified and reduced (unlike CASE) in case of statements like `name="One" OR name="Two"`, RexSimplifier will eliminate produced OR at all.  After such reduction a calculated cost will be much more reliable and a generated code will be simpler.




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