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Data Mining And Data Warehousing

Frequent Pattern Growth

Frequent Pattern Growth (FP-Growth) in Association Analysis

FP-Growth is an advanced and efficient algorithm for frequent itemset mining, commonly used in association rule learning. It addresses the performance limitations of the Apriori algorithm by avoiding costly candidate generation and repeated database scans.

What is FP-Growth?

FP-Growth stands for Frequent Pattern Growth. It finds frequent itemsets directly from the database using a special structure called an FP-tree (Frequent Pattern Tree).

How FP-Growth Works (in 2 Main Steps):
  • Step 1: Build the FP-Tree
    • Scan the database once to determine item frequencies.
    • Sort items in descending order of frequency.
    • Build a compressed tree structure (FP-tree) where paths represent itemsets.
    • Items shared by multiple transactions share nodes (saves space!).
  • Step 2: Extract Frequent Patterns
    • Start from the bottom of the tree, find frequent items and grow patterns recursively.
    • Use conditional FP-trees to mine larger patterns without candidate generation.
Why FP-Growth is Better than Apriori
FeatureAprioriFP-Growth
ApproachGenerate-and-test (candidates)Divide-and-conquer (FP-tree)
Memory usageHigh (due to candidates)Lower (compact tree structure)
SpeedSlower for large datasetsFaster and more scalable
DB ScansMultipleUsually 2