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Chapter 5: Query Execution and Scoring

Learn how queries are planned, executed, and scored for optimal performance.

Chapter Overview​

When a query arrives at a search engine, a complex series of operations transforms it from text into ranked results. This chapter covers query parsing, planning, and execution, along with the scoring algorithms that determine relevance.

Mastering query execution is critical for optimizing search latency, understanding why certain results rank higher, and debugging unexpected query behavior.

5.1 Query Execution Models​

5.1.1 Query trees

5.1.2 Query planning

5.1.3 Scorers and iterators

5.2 Query-Time Analysis​

5.2.1 Analysis chains

5.2.2 Impedance mismatches

5.2.3 Read amplification and segment fanout

5.3 Accuracy and Efficiency​

5.3.1 Early termination

5.3.2 Filtering vs. ranking

5.3.3 Boosting and tradeoffs

Examples​

Examples coming soon.

Code examples for this chapter will demonstrate query planning, scoring mechanics, and performance optimization techniques using Lucenia's query APIs.