From 855def58e8e20414fda450c32b0f10594cee124d Mon Sep 17 00:00:00 2001
From: 924060929 <lanhuajian@selectdb.com>
Date: Mon, 1 Sep 2025 14:17:23 +0800
Subject: [PATCH] [opt](nereids) improve performance of cast big string to
 complex type (#55476)

improve performance of cast big string to complex type
1. avoid throw cast exception
2. avoid compute full hash code of the big string literal


```sql
select cast('[1,2,3,4,5,6,7,8,...,99999]' as array<float>);
```
---
 .../expression/rules/FoldConstantRuleOnFE.java |  4 ++++
 .../expressions/literal/StringLikeLiteral.java | 18 ++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/expression/rules/FoldConstantRuleOnFE.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/expression/rules/FoldConstantRuleOnFE.java
index afd6e788cd10ed..d9b794707f9db6 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/expression/rules/FoldConstantRuleOnFE.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/expression/rules/FoldConstantRuleOnFE.java
@@ -494,6 +494,10 @@ public Expression visitCast(Cast cast, ExpressionRewriteContext context) {
             }
         }
         try {
+            // TODO: support no throw exception in `checkedCastTo` and return Optional<Expression>
+            if (cast.child().getDataType().isStringLikeType() && dataType.isComplexType()) {
+                return cast;
+            }
             Expression castResult = child.checkedCastTo(dataType);
             if (!Objects.equals(castResult, cast) && !Objects.equals(castResult, child)) {
                 castResult = rewrite(castResult, context);
diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/literal/StringLikeLiteral.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/literal/StringLikeLiteral.java
index d1d98fe218afd5..9c52e763a1ae6e 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/literal/StringLikeLiteral.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/literal/StringLikeLiteral.java
@@ -75,6 +75,24 @@ public boolean equals(Object o) {
         return Objects.equals(value, that.value);
     }
 
+    @Override
+    public int fastChildrenHashCode() {
+        return doComputeHashCode();
+    }
+
+    @Override
+    protected int computeHashCode() {
+        return doComputeHashCode();
+    }
+
+    private int doComputeHashCode() {
+        if (value != null && value.length() > 36) {
+            return value.substring(0, 36).hashCode();
+        } else {
+            return Objects.hashCode(getValue());
+        }
+    }
+
     @Override
     public String toString() {
         return "'" + value + "'";