Theory

Risk pooling: premiums in, claims and expenses out.

Policyholder, coverage, limit, deductible, policy period, renewal and lapse.

Written, earned and unearned premium, and exposure.

The event versus the request for payment, and a claim's life.

Paid versus incurred, case reserves and IBNR.

Frequency, severity, loss ratio, combined ratio and retention.

Development triangles and a first look at the chain ladder.

Direct sales, brokers and commission.

Red flags, and how constraints protect the numbers.

Personal data, least privilege and regulatory reporting.

Tables, keys, types, null, and the parts of SQL.

The logical order of a SELECT, three-valued logic and types.

One to many, many to many, the kinds of join and the fan-out trap.

Aggregates, nulls, WHERE against HAVING, ratios and subqueries.

Constraints, normal forms and B-tree indexes.

Saved queries, named steps, and calculations over related rows.

PL/pgSQL, volatility, BEFORE and AFTER, and when to use a constraint.

Statistics, scans, join methods and sargable conditions.

json against jsonb, containment, GIN indexes and trigrams.

ACID, MVCC, roles, row-level security and backups.