olap_guide

OLAP Analytics Usage Guide

Version: v1.3.0 Phase 2
Status: Production-Ready
Last Updated: December 22, 2025

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Overview

ThemisDB's OLAP (Online Analytical Processing) Analytics engine provides powerful analytical capabilities for complex data analysis tasks. The engine supports GROUP BY operations, CUBE/ROLLUP queries, window functions, and advanced aggregations with columnar processing for optimal performance.

Key Features

1. Flexible Grouping Operations

• Simple GROUP BY with single or multiple dimensions
• CUBE for generating all possible grouping combinations
• ROLLUP for hierarchical aggregations
• GROUPING SETS for custom grouping combinations

2. Window Functions

• ROW_NUMBER: Sequential row numbering within partitions
• RANK: Ranking with gaps for ties
• DENSE_RANK: Ranking without gaps
• LAG: Access previous row values
• LEAD: Access next row values

3. Advanced Aggregations

• Standard: COUNT, SUM, AVG, MIN, MAX
• Statistical: STDDEV, VARIANCE, MEDIAN, PERCENTILE
• Specialized: COUNT_DISTINCT, FIRST, LAST

4. Performance Optimization

• Columnar storage for efficient scanning
• Query plan optimization
• Apache Arrow integration (optional)
• Parallel processing support

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See full documentation at https://github.com/makr-code/ThemisDB

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Last Updated: December 22, 2025
Version: v1.3.0 Phase 2
Status: Production-Ready