String-Similarity

• Trigram Similarity

  Jaccard similarity over character trigrams. Used by PostgreSQL pg_trgm for fast approximate matching.

• Longest Common Substring

  Longest contiguous character sequence common to two strings. Useful for plagiarism detection and similarity measurement.

• Longest Common Subsequence

  Longest sequence of characters common to two strings in order (not necessarily contiguous). Foundation for sequence alignment and diff algorithms.

• Levenshtein Distance

  Edit distance allowing insertions, deletions, and substitutions. Canonical metric for string similarity and typo tolerance.

• Jaro-Winkler Similarity

  Jaro similarity with prefix bonus for matching initial characters. Improves accuracy for name and record matching.

• Jaro Similarity

  String similarity metric for short strings based on matching characters and transpositions. Commonly used in record linkage and data quality.

• Hamming Distance

  Number of positions at which two equal-length strings differ. Efficient metric for fixed-length codes and binary data.

• Edit Distance

  Minimum number of single-character operations (insertions, deletions, substitutions) to transform one string into another. Foundation for similarity metrics.

• Damerau-Levenshtein Distance

  Edit distance including transpositions (swapping adjacent characters). Captures more common typos than Levenshtein alone.