# 06 - Convert to PostgreSQL (indexed + partitioned)

## Context / Goal
Build the production-grade relational variant: the system-of-record candidate per the existing Storage ADR (PostgreSQL primary, RDF as deferred virtual layer).

## Dependencies
03.

## Input
CSV tree.

## Processing instructions
- Local PostgreSQL 16, database `tribo`. Same logical schema as task 05 with PostgreSQL types (`INT`, `REAL`, `TIMESTAMPTZ`, `TEXT`).
- `friction_cycles` and `friction_loop_points`: declarative RANGE partitioning by `track_id` (12 partitions of 120 tracks) - models the partitioning strategy needed at 600 GB scale.
- Load via `COPY FROM STDIN` (psycopg3 `copy`), not INSERT.
- Indexes after load: PK b-trees; `tracks(environment, load_mn)`, `coupons(au_wtpct_mean)`, `nanoindentation(coupon_id)`, BRIN on `friction_cycles(cycle)` per partition.
- `track_summary` as a materialized view (`cof_ss_mean` = avg of cycles > run_in threshold; `run_in_cycles` via first cycle where |cof - cof_ss| < 2σ).
- `VACUUM ANALYZE` after load. Record `pg_total_relation_size` per table and total into `storage_sizes.csv`.
- Also export a compressed dump `./out/pg/tribo.dump` (pg_dump -Fc) for archiving-format comparison.

## Output
- Live `tribo` database + `./out/pg/tribo.dump`.
- Marker `./out/.done/06.ok`.