DatabaseMetaData#getFunctionColumns's result has duplicate

[onacit]

Please read https://stackoverflow.com/help/minimal-reproducible-example

Describe the issue
DatabaseMetaData#getFunctionColumns()'s result has duplicate.

Driver Version?
42.7.2

Java Version?

IBM Semeru Runtime Open Edition 21.0.2.0 (build 21.0.2+13-LTS)
Eclipse OpenJ9 VM 21.0.2.0 (build openj9-0.43.0, JRE 21 Mac OS X aarch64-64-Bit 20240116_96 (JIT enabled, AOT enabled)
OpenJ9   - 2c3d78b48
OMR      - ea8124dbc
JCL      - 78c4500a434 based on jdk-21.0.2+13)

OS Version?

che Maven 3.9.6 (bc0240f3c744dd6b6ec2920b3cd08dcc295161ae)
Maven home: /Users/onacit/.m2/wrapper/dists/apache-maven-3.9.6-bin/439sdfsg2nbdob9ciift5h5nse/apache-maven-3.9.6
Java version: 21.0.2, vendor: IBM Corporation, runtime: /Library/Java/JavaVirtualMachines/ibm-semeru-open-21.jdk/Contents/Home
Default locale: en_US, platform encoding: UTF-8
OS name: "mac os x", version: "14.3.1", arch: "aarch64", family: "mac"

PostgreSQL Version?

16.1 (Debian 16.1-1.pgdg120+1)

To Reproduce
Invoke getFunctions() and getFunctionColumns().

Expected behaviour
Should not contain any duplicates.

Logs

Found duplicate(s):
  [FunctionColumn(super=AbstractMetadataType(super=com.github.jinahya.database.metadata.bind.FunctionColumn@3bd3b492, unmappedValues={}),
    functionCat=null,
    functionSchem=pg_catalog,
    functionName=pg_create_logical_replication_slot,
    columnName=slot_name,
    columnType=3,
    dataType=12,
    typeName=name,
    precision=null, length=null, scale=null, radix=null, nullable=2, remarks=null, charOctetLength=null, ordinalPosition=5, isNullable=,
    specificName=pg_create_logical_replication_slot_3786)]
in:
  [
  FunctionColumn(super=AbstractMetadataType(super=com.github.jinahya.database.metadata.bind.FunctionColumn@3bd3b492, unmappedValues={}),
    functionCat=null,
    functionSchem=pg_catalog,
    functionName=pg_create_logical_replication_slot,
    columnName=slot_name,
    columnType=1, dataType=12, typeName=name, precision=null, length=null, scale=null, radix=null, nullable=2, remarks=null, charOctetLength=null, ordinalPosition=1, isNullable=,
    specificName=pg_create_logical_replication_slot_3786),
  FunctionColumn(super=AbstractMetadataType(super=com.github.jinahya.database.metadata.bind.FunctionColumn@43c8832f, unmappedValues={}), functionCat=null, functionSchem=pg_catalog, functionName=pg_create_logical_replication_slot, columnName=plugin, columnType=1, dataType=12, typeName=name, precision=null, length=null, scale=null, radix=null, nullable=2, remarks=null, charOctetLength=null, ordinalPosition=2, isNullable=, specificName=pg_create_logical_replication_slot_3786),
  FunctionColumn(super=AbstractMetadataType(super=com.github.jinahya.database.metadata.bind.FunctionColumn@10deff19, unmappedValues={}), functionCat=null, functionSchem=pg_catalog, functionName=pg_create_logical_replication_slot, columnName=temporary, columnType=1, dataType=-7, typeName=bool, precision=null, length=null, scale=null, radix=null, nullable=2, remarks=null, charOctetLength=null, ordinalPosition=3, isNullable=, specificName=pg_create_logical_replication_slot_3786),
  FunctionColumn(super=AbstractMetadataType(super=com.github.jinahya.database.metadata.bind.FunctionColumn@e0e95cc3, unmappedValues={}), functionCat=null, functionSchem=pg_catalog, functionName=pg_create_logical_replication_slot, columnName=twophase, columnType=1, dataType=-7, typeName=bool, precision=null, length=null, scale=null, radix=null, nullable=2, remarks=null, charOctetLength=null, ordinalPosition=4, isNullable=, specificName=pg_create_logical_replication_slot_3786),
  FunctionColumn(super=AbstractMetadataType(super=com.github.jinahya.database.metadata.bind.FunctionColumn@3bd3b492, unmappedValues={}),
    functionCat=null,
    functionSchem=pg_catalog,
    functionName=pg_create_logical_replication_slot,
    columnName=slot_name,
    columnType=3, dataType=12, typeName=name, precision=null, length=null, scale=null, radix=null, nullable=2, remarks=null, charOctetLength=null, ordinalPosition=5, isNullable=,
    specificName=pg_create_logical_replication_slot_3786),
  FunctionColumn(super=AbstractMetadataType(super=com.github.jinahya.database.metadata.bind.FunctionColumn@ccb2a14b, unmappedValues={}), functionCat=null, functionSchem=pg_catalog, functionName=pg_create_logical_replication_slot, columnName=lsn, columnType=3, dataType=1111, typeName=pg_lsn, precision=null, length=null, scale=null, radix=null, nullable=2, remarks=null, charOctetLength=null, ordinalPosition=6, isNullable=, specificName=pg_create_logical_replication_slot_3786)
  ]

[davecramer]

Running

 try (ResultSet rsfuncs = metaData.getFunctions(null, null, null)){
                while (rsfuncs.next()) {
                    System.out.println("Function Name: " + rsfuncs.getString("FUNCTION_NAME"));
                }
            }

prints out exactly one function named `pg_create_logical_replication_slot'

Function Name: pg_copy_physical_replication_slot
Function Name: pg_create_logical_replication_slot
Function Name: pg_create_physical_replication_slot