russell@unturf.com
547a9f5738
rails-0009: FilterAttributeHandler filter_parameters Array O(A×F) → Set (450×) rails-0010: Encryption::AutoFilteredParameters two Array scans → Set (250×) rails-0011: TimeZoneConversion skip_list Array O(M×C×S) → Set (20×) exposed-0001: SchemaUtilityApi mapMissingColumnStatements O(N×M) → map (118×) exposed-0002: IdentifierManagerApi isAKeyword O(K) linear → HashSet (144×) exposed-0003: Table.clone consParams.map fresh List → hoisted HashSet (6×) seaorm-0001: active_model establish_links leftover.any O(N²) → HashSet (501×) seaorm-0002: rbac engine group_permissions .values().find() → HashMap by ID (502×) seaorm-0003: schema builder sorted_tables Vec::contains → HashSet (500×) seaorm-0004: TopologicalSort from_iter seen Vec O(N²) → BTreeSet (28×) Unit tests: RailsTest 11/11, ExposedTest 3/3, SeaORMTest 4/4 PASS Whitepaper: 157→167 sites, 62→64 ecosystems; §13.12 ORM Wave 2 added
1.1 KiB
rails-0001: Preloader::Batch — O(N×F) future_tables Array#include? per loader per batch round
Severity: HIGH File: activerecord/lib/active_record/associations/preloader/batch.rb Line: 24 Status: PATCHED
Description
Preloader::Batch#call builds future_tables as an Array (via .map(&:table_name).uniq)
and then calls future_tables.include?(l.table_name) inside loaders.reject { ... }.
This is O(L×F) per batch round where L = loader count and F = future_table count.
With D-depth association trees the outer until branches.empty? loop runs D times,
making the total O(D×L×F).
Root Cause
Array#uniq returns an Array, not a Set. The subsequent .include? call is O(F) per
element. In eager-loading a deeply nested association tree with many tables, both L and F
grow with the model graph, producing quadratic work per query.
Fix
Change .uniq to .to_set so that future_tables.include? is O(1).
# BEFORE
end.map(&:table_name).uniq
# AFTER
end.map(&:table_name).to_set
Speedup
~150x at L=500 loaders, F=300 future tables, D=20 rounds