import { Context, Path } from '@signalk/server-api';
/**
 * Schema information for an object-valued path
 */
export interface PathComponentSchema {
    components: Map<string, ComponentInfo>;
    timestamp: number;
}
export interface ComponentInfo {
    name: string;
    columnName: string;
    dataType: 'numeric' | 'string' | 'boolean' | 'unknown';
}
/**
 * Get the component schema for an object-valued path across all parquet files
 * Returns the union of all value_* columns found in any file for this path
 * Uses Hive-partitioned directory structure: tier=raw/context=.../path=.../
 */
export declare function getPathComponentSchema(dataDir: string, context: Context, pathStr: Path): Promise<PathComponentSchema | null>;
/**
 * Clear the schema cache (useful for testing or when data structure changes)
 */
export declare function clearSchemaCache(): void;
/**
 * Infer data type category from DuckDB type string
 */
export declare function inferDataTypeCategory(duckdbType: string): ComponentInfo['dataType'];
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