Module: Pilipinas::Db::Concerns::StaticRecord

Extended by:

ActiveSupport::Concern

Included in:

Barangay, Pilipinas::Db::City, Province, Region

Defined in:

lib/pilipinas/db/concerns/static_record.rb

Overview

Shared ActiveRecord concern applied to every Pilipinas DB model.

What this solves

The four pilipinas_* tables hold **static reference data** that never changes after the initial seed. Plain ActiveRecord has several sources of unnecessary memory allocation for this workload:

1. **All columns are loaded by default**, including lft/rgt (nested-set hierarchy fields), longitude/latitude, income_class, etc. — most callers only ever need code + name.

2. **STI type-column checking** — AR looks for a type column on every query; these tables have none, so that check is pure overhead.

3. **Dirty-tracking and callbacks** — pointless for read-only data.

4. **Accidental writes** — a stray save or update on static data is almost always a bug; it should raise immediately.

5. **Unbatched mass loads** — loading 42 k+ barangay rows in a single SQL statement creates a huge transient Array before AR can even instantiate objects.

Optimizations applied

• readonly? returns true for persisted records only — accidental update!/save!/destroy on fetched rows raise ActiveRecord::ReadOnlyRecord; new records stay writable so the Loader and test fixtures can still call create!.

• self.inheritance_column = :_sti_disabled: removes STI type-column look-up from every query.

• .lite scope: selects only id, location_id, code, name —skips every spatial/hierarchy column, ~60 % less data per row for the barangays table (the largest one).

• .by_code / .by_name scopes: paired with .lite these give the caller a single, readable one-liner that minimises allocations.

• Association lambdas on has_many restrict the SELECT to the five columns actually needed for traversal, so region.provinces, province.cities, and city.barangays are all automatically lean.

Examples:

Lean look-up

Pilipinas::Db::Region.lite.by_name("NCR")
# SELECT id, location_id, code, name FROM pilipinas_regions
# WHERE LOWER(name) = LOWER('NCR') LIMIT 1

Traversal — no wasted columns loaded

region.provinces   # SELECT id, location_id, parent_id, code, name …
province.cities    # SELECT id, location_id, parent_id, code, name …
city.barangays     # SELECT id, location_id, parent_id, code, name …

Constant Summary

LITE_COLUMNS =

Columns loaded for associations and the lite scope. Excludes: lft, rgt, longitude, latitude, parent_id (for lite),

income_class, urban_rural, district, timestamps.

%i[id location_id code name].freeze

TRAVERSAL_COLUMNS =

%i[id location_id parent_id code name].freeze

Instance Method Summary

• #readonly? ⇒ Boolean

  Persisted instances loaded from a pilipinas_* table are permanently read-only: update!, save, and destroy all raise ActiveRecord::ReadOnlyRecord.

Instance Method Details

#readonly? ⇒ Boolean

Persisted instances loaded from a pilipinas_* table are permanently read-only: update!, save, and destroy all raise ActiveRecord::ReadOnlyRecord. New (unsaved) objects are writable so that the Loader can still call create! on the fallback path and so that specs can build fixtures with create!.

Overriding readonly? is more efficient than an after_initialize callback because it is only called when AR is about to perform a write operation — it adds zero per-record overhead on reads.

Returns:

• (Boolean) —

  true for persisted records, false for new ones

# File 'lib/pilipinas/db/concerns/static_record.rb', line 111

def readonly?
  !new_record?
end