[Feature] Support Spark expression: seconds_of_time #3129

What is the problem the feature request solves?

Note: This issue was generated with AI assistance. The specification details have been extracted from Spark documentation and may need verification.

Comet does not currently support the Spark seconds_of_time function, causing queries using this function to fall back to Spark's JVM execution instead of running natively on DataFusion.

The SecondsOfTime expression extracts the seconds component from a time-related value. This is a unary expression that operates on a single child expression and returns the seconds portion as an integer value.

Supporting this expression would allow more Spark workloads to benefit from Comet's native acceleration.

Describe the potential solution

Spark Specification

Syntax:

-- SQL syntax (implementation-dependent)
SECONDS(time_expression)

// DataFrame API usage
import org.apache.spark.sql.catalyst.expressions.SecondsOfTime
SecondsOfTime(child_expression)

Arguments:

Return Type: Integer type representing the seconds component (typically 0-59).

Supported Data Types:

• Timestamp types
• Time-related string formats
• Date/time structures that contain seconds information

Edge Cases:

• Null handling: Returns null if the child expression evaluates to null
• Invalid time formats: Behavior depends on the underlying time parsing implementation
• Leap seconds: Handles standard 0-59 seconds range, special leap second handling may vary
• Timezone considerations: Seconds extraction is typically timezone-independent

Examples:

-- Example SQL usage (hypothetical)
SELECT SECONDS(current_timestamp()) as current_seconds;
SELECT SECONDS('2023-12-25 14:30:45') as extracted_seconds; -- Returns 45

// Example DataFrame API usage
import org.apache.spark.sql.functions._
import org.apache.spark.sql.catalyst.expressions.SecondsOfTime

// Using in a DataFrame transformation
df.select(SecondsOfTime(col("timestamp_column")))

Implementation Approach

See the Comet guide on adding new expressions for detailed instructions.

1. Scala Serde: Add expression handler in spark/src/main/scala/org/apache/comet/serde/
2. Register: Add to appropriate map in QueryPlanSerde.scala
3. Protobuf: Add message type in native/proto/src/proto/expr.proto if needed
4. Rust: Implement in native/spark-expr/src/ (check if DataFusion has built-in support first)

Additional context

Difficulty: Medium
Spark Expression Class: org.apache.spark.sql.catalyst.expressions.SecondsOfTime

Related:

• MinutesOfTime - Extracts minutes component
• HoursOfTime - Extracts hours component
• second() - Built-in SQL function for seconds extraction
• Time extraction expressions in Spark Catalyst

This issue was auto-generated from Spark reference documentation.