feat(nereids): add typeof scalar function by ahmedsaid47 · Pull Request #61500 · apache/doris

ahmedsaid47 · 2026-03-19T00:57:59Z

What problem does this PR solve?

Issue Number: close #48203

Related PR: #48201

Problem Summary:

Add the Trino/Presto typeof(expr) scalar function in Nereids.

Before this patch, typeof(...) was not supported in Doris Nereids and Trino/Presto compatibility queries using it could not be analyzed successfully. This implementation adds typeof(expr) -> varchar as an FE-only function and rewrites typeof(...) to a string literal during analysis, so it does not require a BE runtime function. The patch also adds Trino-compatible type display formatting for literals, casts, arrays, maps, rows, decimals, and nested types.

Release note

None

Check List (For Author)

Test
- Regression test
- Unit Test
- Manual test (add detailed scripts or steps below)
- No need to test or manual test. Explain why:
  - This is a refactor/code format and no logic has been changed.
  - Previous test can cover this change.
  - No code files have been changed.
  - Other reason

Manual test steps:

cd fe && mvn -pl fe-core -am -Dcheckstyle.skip=true -Dspotbugs.skip=true -DfailIfNoTests=false -Dtest=org.apache.doris.nereids.trees.expressions.functions.scalar.TypeOfTest test
Start a local single-node Doris cluster with 1 FE and 1 BE.
./run-regression-test.sh --run -f regression-test/suites/external_table_p0/dialect_compatible/sql/presto/scalar/TestTypeOfFunction.sql -forceGenOut -parallel 1 -times 1
./run-regression-test.sh --run -f regression-test/suites/external_table_p0/dialect_compatible/sql/presto/scalar/TestTypeOfFunction.sql -parallel 1 -times 1

Behavior changed:
- No.
- Yes. Add typeof(expr) -> varchar.
Does this need documentation?
- No.
- Yes.

Check List (For Reviewer who merge this PR)

Confirm the release note
Confirm test cases
Confirm document
Add branch pick label

hello-stephen · 2026-03-19T00:58:06Z

Thank you for your contribution to Apache Doris.
Don't know what should be done next? See How to process your PR.

Please clearly describe your PR:

What problem was fixed (it's best to include specific error reporting information). How it was fixed.
Which behaviors were modified. What was the previous behavior, what is it now, why was it modified, and what possible impacts might there be.
What features were added. Why was this function added?
Which code was refactored and why was this part of the code refactored?
Which functions were optimized and what is the difference before and after the optimization?

ahmedsaid47 · 2026-03-19T10:43:36Z

Validation completed on a real single-node Doris cluster (1 FE + 1 BE).

Executed:

mvn -pl fe-core -am -Dcheckstyle.skip=true -Dspotbugs.skip=true -DfailIfNoTests=false -Dtest=org.apache.doris.nereids.trees.expressions.functions.scalar.TypeOfTest test
./run-regression-test.sh --run -f regression-test/suites/external_table_p0/dialect_compatible/sql/presto/scalar/TestTypeOfFunction.sql -forceGenOut -parallel 1 -times 1
./run-regression-test.sh --run -f regression-test/suites/external_table_p0/dialect_compatible/sql/presto/scalar/TestTypeOfFunction.sql -parallel 1 -times 1

Result: TypeOfTest passed and TestTypeOfFunction passed with 0 failed suites on a real FE+BE runtime.

Copilot

Pull request overview

Adds Trino/Presto-compatible typeof(expr) support to the Nereids FE analyzer by rewriting typeof(...) into a VARCHAR literal during analysis, avoiding any BE runtime dependency. This also introduces Trino-style type display formatting for several Doris/Nereids data types so the returned type strings match Trino/Presto expectations.

Changes:

Introduce TypeOf scalar function (analyze-time rewrite to VarcharLiteral) and register/visit it in Nereids.
Capture original CAST/TRY_CAST type SQL text (explicitTypeSql) to improve Trino-compatible type-name display (notably for DECIMAL defaults).
Add unit tests and update Presto-dialect regression SQL + expected output for typeof.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
regression-test/suites/external_table_p0/dialect_compatible/sql/presto/scalar/TestTypeOfFunction.sql	Adds `typeof(...)` queries under Presto dialect for various types and expressions.
regression-test/data/external_table_p0/dialect_compatible/sql/presto/scalar/TestTypeOfFunction.out	Adds expected outputs matching Trino/Presto type display strings.
fe/fe-core/src/test/java/org/apache/doris/nereids/trees/expressions/functions/scalar/TypeOfTest.java	New unit tests covering analyze-time rewrite + complex type display formatting.
fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/visitor/ScalarFunctionVisitor.java	Adds visitor hook for the new `TypeOf` scalar function.
fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/TryCast.java	Threads `explicitTypeSql` through TRY_CAST construction/cloning paths.
fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/functions/scalar/TypeOfDisplayName.java	New utility to produce Trino-compatible type display names for TYPEOF.
fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/functions/scalar/TypeOf.java	New scalar function implementation: custom signature + analyze-time rewrite.
fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/Cast.java	Adds `explicitTypeSql` storage/accessor and propagates it through cloning APIs.
fe/fe-core/src/main/java/org/apache/doris/nereids/parser/LogicalPlanBuilder.java	Persists CAST/TRY_CAST original type SQL text into Cast/TryCast nodes.
fe/fe-core/src/main/java/org/apache/doris/catalog/BuiltinScalarFunctions.java	Registers `typeof` as a built-in scalar function.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

You can also share your feedback on Copilot code review. Take the survey.

ahmedsaid47 · 2026-03-19T12:24:58Z

fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/Cast.java

+    public Optional<String> getExplicitTypeSql() {
+        return Optional.ofNullable(explicitTypeSql);
+    }


Fixed in 0cbb1d9. Cast.equals() and computeHashCode() now include both isExplicitType and explicitTypeSql, so casts with the same analyzed target type but different explicit type text no longer collide in expression-keyed rewrites/CSE.

ahmedsaid47 · 2026-03-19T12:24:58Z

fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/TryCast.java

    public TryCast withChildren(List<Expression> children) {
        Preconditions.checkArgument(children.size() == 1);
-        return new TryCast(children, targetType, isExplicitType);
+        return new TryCast(children, targetType, isExplicitType, explicitTypeSql);
    }


Fixed in 0cbb1d9 as well. TryCast now inherits the metadata-aware equality semantics from Cast, and its hash code also includes the explicit type metadata so TRY_CAST expressions stay consistent with their behavior in rewrite/CSE paths.

ahmedsaid47 · 2026-03-19T12:24:58Z

...re/src/test/java/org/apache/doris/nereids/trees/expressions/functions/scalar/TypeOfTest.java

+    @Test
+    void testAnalyzeTimeRewriteForTrinoExamples() {
+        assertTypeOfRewrite("typeof(123)", "integer");
+        assertTypeOfRewrite("typeof('cat')", "varchar(3)");
+        assertTypeOfRewrite("typeof(cast(1 as bigint))", "bigint");
+        assertTypeOfRewrite("typeof(cast(1 as varchar))", "varchar");
+        assertTypeOfRewrite("typeof(cast(null as varchar(10)))", "varchar(10)");
+        assertTypeOfRewrite("typeof(try_cast(null as varchar(10)))", "varchar(10)");
+        assertTypeOfRewrite("typeof(cast(null as char(3)))", "char(3)");
+        assertTypeOfRewrite("typeof(cast(null as decimal(5,1)))", "decimal(5,1)");
+        assertTypeOfRewrite("typeof(cast(null as decimal))", "decimal(38,0)");
+        assertTypeOfRewrite("typeof(try_cast(null as decimal))", "decimal(38,0)");
+        assertTypeOfRewrite("typeof(concat('ala', 'ma', 'kota'))", "varchar");
+        assertTypeOfRewrite("typeof(typeof(123))", "varchar");
+        assertTypeOfRewrite("typeof(2 + sin(2) + 2.3)", "double");
+    }


Added targeted assertions in 0cbb1d9 for the remaining mappings introduced by TypeOfDisplayName, including float -> real, varbinary -> varbinary, datev2 -> date, and timev2 -> time(0).

ahmedsaid47 · 2026-03-19T12:26:22Z

Pushed follow-up commit 0cbb1d90 to address the review feedback on Cast/TryCast equality-hash semantics and to add the missing TypeOfDisplayName mapping assertions. Re-ran TypeOfTest on the latest head and it passed.

ahmedsaid47 added 2 commits March 18, 2026 23:47

feat(nereids): add typeof scalar function

d4055e6

test(regression): add typeof outputs

d8de512

ahmedsaid47 marked this pull request as ready for review March 19, 2026 10:42

Copilot AI review requested due to automatic review settings March 19, 2026 10:42

Copilot AI reviewed Mar 19, 2026

View reviewed changes

fix(nereids): include cast type metadata in equality

0cbb1d9

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

feat(nereids): add typeof scalar function#61500

feat(nereids): add typeof scalar function#61500
ahmedsaid47 wants to merge 3 commits intoapache:masterfrom
ahmedsaid47:feat/typeof

ahmedsaid47 commented Mar 19, 2026 •

edited

Loading

Uh oh!

hello-stephen commented Mar 19, 2026

Uh oh!

ahmedsaid47 commented Mar 19, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

ahmedsaid47 Mar 19, 2026

Uh oh!

ahmedsaid47 Mar 19, 2026

Uh oh!

ahmedsaid47 Mar 19, 2026

Uh oh!

ahmedsaid47 commented Mar 19, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Conversation

ahmedsaid47 commented Mar 19, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

What problem does this PR solve?

Release note

Check List (For Author)

Check List (For Reviewer who merge this PR)

Uh oh!

hello-stephen commented Mar 19, 2026

Uh oh!

ahmedsaid47 commented Mar 19, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

ahmedsaid47 Mar 19, 2026

Choose a reason for hiding this comment

Uh oh!

ahmedsaid47 Mar 19, 2026

Choose a reason for hiding this comment

Uh oh!

ahmedsaid47 Mar 19, 2026

Choose a reason for hiding this comment

Uh oh!

ahmedsaid47 commented Mar 19, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

ahmedsaid47 commented Mar 19, 2026 •

edited

Loading