[SPARK-49909][SQL] Fix the pretty name of some expressions

[panbingkun]

What changes were proposed in this pull request?

The pr aims to fix the pretty name of some expressions, includes: random, to_varchar, current_database, curdate, dateadd and array_agg.

Why are the changes needed?

The actual function name used does not match the displayed name, as shown below:

• Before:

• After:

Does this PR introduce any user-facing change?

Yes, Make the header of the data seen by the end-user from Spark SQL consistent with the actual function name used.

How was this patch tested?

• Pass GA.
• Update existed UT.

Was this patch authored or co-authored using generative AI tooling?

No.

[MaxGekk]

+1, LGTM. Merging to master.
Thank you, @panbingkun and @HyukjinKwon for review.

[MaxGekk]

@panbingkun I think we should backport the fix. Could you open separate PRs, please, because your changes cause conflicts in branch-3.5 (and maybe in branch-3.4).

[panbingkun]

@panbingkun I think we should backport the fix. Could you open separate PRs, please, because your changes cause conflicts in branch-3.5 (and maybe in branch-3.4).

Sure, allow me to complete it.

[gatorsmile]

The benefit of this fix is minimal, but it will disrupt the queries of many end users because they rely on the auto-generated alias.

[panbingkun]

• I overlooked another scenario in the PR description, when an error occurs, the function name prompted may not match the actual function name, eg:

spark-sql (default)> select random("1");
[DATATYPE_MISMATCH.UNEXPECTED_INPUT_TYPE] Cannot resolve "rand(1)" due to data type mismatch: The first parameter requires the ("INT" or "BIGINT") type, however "1" has the type "STRING". SQLSTATE: 42K09; line 1 pos 7;
'Project [unresolvedalias(random(1))]
+- OneRowRelation

• Because in our spark implementation, multiple function’s names often correspond to the same implementation. eg:
  

  spark/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/FunctionRegistry.scala

  Lines 404 to 405 in 78308da

  	expressionBuilder("ceil", CeilExpressionBuilder),
  	expressionBuilder("ceiling", CeilExpressionBuilder, true),

  
  

  spark/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/FunctionRegistry.scala

  Lines 433 to 434 in 78308da

  	expression[ShiftLeft]("shiftleft"),
  	expression[ShiftRight]("shiftright"),

  
  

  spark/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/FunctionRegistry.scala

  Lines 384 to 385 in 78308da

  	expression[Rand]("rand"),
  	expression[Rand]("random", true, Some("3.0.0")),

• If logic similar to getTagValue(FunctionRegistry.FUNC_ALIAS).getOrElse("...") is not used in the implementation, the above problems may occur (the actual functions used are inconsistent with the schema or error prompts).

• Of course, if we decide to revert it, I am also okay.

[panbingkun]

revert pr: #48530

[panbingkun]

After the master branch merges the revert PR, I will submit PRs to branch-3.5 and branch-3.4 respectively to revert these changes.

[panbingkun]

branch-3.5 revert: #48531
branch-3.4 revert: #48532