SecondsOfTime¶

Overview¶

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.

Syntax¶

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

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

Arguments¶

Argument	Type	Description
child	Expression	The input expression containing time data from which to extract seconds

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

Algorithm¶

Evaluates the child expression to obtain the input time value
Extracts the seconds component from the time representation
Returns the seconds value as an integer
Handles null propagation from the child expression
Utilizes the withNewChildrenInternal method for expression tree manipulation

Partitioning Behavior¶

How this expression affects partitioning:

Preserves partitioning as it's a deterministic transformation
Does not require shuffle operations
Can be pushed down in query optimization

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

Code Generation¶

This expression likely supports Spark's Tungsten code generation for optimized execution, though the specific implementation would depend on the complete class definition and any codegen-related methods.

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")))