# Decimal column policy

Use the bare `numeric` column type for ordinary exact base-10 values. It stores
the value without a schema-defined decimal-place limit and is the recommended
choice for quantities, percentages, rates, ratios and measurements. Use
`money` for currency amounts; its currency and rounding policy are separate
from this document.

`decimal(p,s)` is an advanced, opt-in compatibility type for strict external
data contracts. `p` limits the total digits and `s` limits the fractional
digits. It is hidden from the normal table-designer type list until fixed-scale
decimal is enabled for that editing session.

Fixed scale is intentionally strict:

- API input outside the declared precision or scale is rejected, never
  silently rounded by PostgreSQL.
- A table script targeting a fixed-scale column must round explicitly before
  returning its value.
- A fixed-scale type cannot be changed through the table editor after the
  table contains data.
- Display precision, allowed increments, minimums and maximums are business
  validation concerns; `decimal(p,s)` is not a substitute for them.

Existing fixed-scale columns remain supported. The opt-in changes discovery,
not storage compatibility.