Index: docs/P6-AdvancedReports/wiki/AdvancedReports.md
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+= Advanced Reports =
+
+This is a solo project (see [wiki:UseCaseModel]),
+so the rubric's "2 per team member" is 2 reports total. Both are implemented as
+single SQL statements, wrapped as callable SQL functions in
+`schema_creation.sql` (`report_top_traders`,
+`report_market_performance`) so they are actual reports inside the prototype — menu
+options `[10]` and `[11]` in `server/reports.go` — not just documentation. No change to
+[wiki:ERModel] or [wiki:RelationalDesign]
+was needed: both reports read `transactions`, `market_trades` and `orders`, all of which
+already carry everything required.
+
+=== Notation used below ===
+
+Both solutions need grouping, aggregation and computed attributes that plain relational
+algebra has no notation for, so the relational-algebra sections use the standard ''extended''
+operators:
+
+||= Symbol =||= Meaning =||
+|| `σ_cond(R)` || selection ||
+|| `π_list(R)` || projection — a list entry `expr → name` is a '''generalized projection''': a computed attribute, not just a column reference ||
+|| `ρ_name(R)` || rename ||
+|| `R ⋈_cond S` || inner join ||
+|| `R ⟕_cond S` || left outer join (needed wherever a group can legitimately have zero matching rows on the other side, e.g. zero profitable periods, zero participating users) ||
+|| `γ_{grouping; agg → name, …}(R)` || grouping/aggregation ||
+|| `τ_attr(R)` || sort, for the presentation order only ||
+
+== Top traders by realized performance ==
+
+=== Data requirements description ===
+
+''"Which users actually made money, how much, how efficiently, and how consistently — over
+a quarter, a year, or several years?"'' This is the natural crypto-exchange analogue of "which
+customers bring the most profit" from the phase brief: a Trader's `available_balance` and
+`invested_balance` (P1 `Users`) show a live snapshot, but they say nothing about performance
+''over a chosen window'', and nothing at all about whether a user's results are one lucky
+quarter or a repeatable pattern. All of it is derivable from
+`transactions` (defined in `schema_creation.sql`) as it already exists: every buy, sell
+and fee is one signed row there (see [wiki:UseCase0004] and
+[wiki:UseCase0005] for how each row is produced), so no new
+column or table is needed.
+
+The `transactions` table, from `schema_creation.sql`:
+
+{{{
+CREATE TABLE project.transactions (
+    id            uuid           PRIMARY KEY DEFAULT gen_random_uuid(),
+    user_id       uuid           NOT NULL REFERENCES project.users(id) ON DELETE CASCADE,
+    type          varchar(50)    NOT NULL CHECK (type IN ('deposit', 'buy', 'sell', 'fee')),
+    amount        numeric(18,4)  NOT NULL,
+    currency      char(3)        NOT NULL DEFAULT 'USD',
+    related_order uuid           REFERENCES project.orders(id),
+    created_at    timestamptz    NOT NULL DEFAULT now(),
+    description   text
+);
+}}}
+
+Given a period `[from, to)`:
+
+ * '''Realized P/L''' = `SUM(amount)` over that user's `buy`, `sell` and `fee` transactions in
+   the period (deposits excluded — they are not trading results).
+ * '''Total invested''' = absolute value of the sum of that user's `buy` transactions in the
+   period (buy amounts are stored negative, per
+   [wiki:ERModel]).
+ * '''ROI %''' = realized P/L ÷ total invested × 100.
+ * The period is additionally bucketed into '''quarters''' internally, regardless of how wide
+   `[from, to)` is, to measure:
+   * '''Profitable / losing periods''' — how many quarters inside the window had positive vs.
+     negative P/L.
+   * '''Consistency %''' = profitable periods ÷ total periods with any activity × 100 — two
+     users can have the same total P/L with very different risk profiles, and this is the
+     number that tells them apart.
+
+=== Solution SQL ===
+
+Implemented as `project.report_top_traders(p_from, p_to)` in
+`schema_creation.sql`:
+
+{{{
+CREATE OR REPLACE FUNCTION project.report_top_traders(p_from timestamptz, p_to timestamptz)
+RETURNS TABLE (
+    username            varchar,
+    realized_pl         numeric,
+    total_invested      numeric,
+    roi_pct             numeric,
+    profitable_periods  bigint,
+    losing_periods      bigint,
+    total_periods       bigint,
+    consistency_pct     numeric
+)
+LANGUAGE sql STABLE AS $$
+    WITH period_pl AS (
+        SELECT
+            t.user_id,
+            date_trunc('quarter', t.created_at)          AS period,
+            SUM(t.amount)                                AS period_pl,
+            SUM(t.amount) FILTER (WHERE t.type = 'buy')  AS period_buy
+        FROM project.transactions t
+        WHERE t.type IN ('buy', 'sell', 'fee')
+          AND t.created_at >= p_from
+          AND t.created_at <  p_to
+        GROUP BY t.user_id, date_trunc('quarter', t.created_at)
+    )
+    SELECT
+        u.username,
+        SUM(pp.period_pl)                                                       AS realized_pl,
+        ABS(SUM(pp.period_buy))                                                 AS total_invested,
+        ROUND(SUM(pp.period_pl) / NULLIF(ABS(SUM(pp.period_buy)), 0) * 100, 2)  AS roi_pct,
+        COUNT(*) FILTER (WHERE pp.period_pl > 0)                                AS profitable_periods,
+        COUNT(*) FILTER (WHERE pp.period_pl < 0)                                AS losing_periods,
+        COUNT(*)                                                                AS total_periods,
+        ROUND(COUNT(*) FILTER (WHERE pp.period_pl > 0)::numeric
+              / NULLIF(COUNT(*), 0) * 100, 2)                                   AS consistency_pct
+    FROM period_pl pp
+    JOIN project.users u ON u.id = pp.user_id
+    GROUP BY u.id, u.username
+    ORDER BY realized_pl DESC;
+$$;
+}}}
+
+One `SELECT`, one `WITH` CTE — the CTE does the quarter bucketing per user, the outer query
+rolls those buckets up into the totals, the ROI/consistency percentages and the ranking.
+
+'''Verified run.''' `reports_demo_data.sql` adds five
+quarters of round-trip trades (2025-07 through 2026-07) on top of the normal seed data
+specifically so this report has more than one period to work with — see that file's header
+(shown in full in the Demonstration data section below)
+for exactly what it inserts and why it is optional rather than part of `-init`. Run against
+PostgreSQL 16 with `data_load.sql` + `reports_demo_data.sql` loaded, through the actual CLI
+(`[10] Report: top traders`, range `2025-01-01` to `2026-09-17`):
+
+{{{
+  Username      Realized P/L        Invested       ROI %   Prof.    Loss   Total  Consist. %
+  ------------------------------------------------------------------------------------------
+  bob              +991.0000       6300.0000       15.73       3       0       3      100.00
+  alice            -475.0000      24250.0000       -1.96       2       3       5       40.00
+}}}
+
+Sorting by raw P/L alone would rank alice above bob if alice's numbers were all positive; here
+it does the opposite, and that is the point of the report — alice traded a much larger total
+(and one of her seeded round trips landed in the same quarter as the ETH buy already in
+`data_load.sql`, tipping that quarter into a loss), while bob's three quarters were smaller
+but every one of them profitable, giving him both the better ROI and a perfect consistency
+score. A single "total profit" column would have hidden that difference completely.
+
+=== Solution Relational Algebra ===
+
+{{{
+T_period  = σ_{type ∈ {buy,sell,fee} ∧ created_at ≥ from ∧ created_at < to} (Transactions)
+
+T_tagged  = π_{user_id, created_at, amount,
+               (type = 'buy' ? amount : 0) → buy_amt} (T_period)
+
+Periods   = γ_{user_id, quarter(created_at) → period ;
+               SUM(amount) → period_pl, SUM(buy_amt) → period_buy} (T_tagged)
+
+Totals      = γ_{user_id ; SUM(period_pl) → realized_pl,
+                 ABS(SUM(period_buy)) → total_invested,
+                 COUNT(*) → total_periods} (Periods)
+Profitable  = γ_{user_id ; COUNT(*) → profitable_periods} (σ_{period_pl > 0} (Periods))
+Losing      = γ_{user_id ; COUNT(*) → losing_periods}     (σ_{period_pl < 0} (Periods))
+
+Combined  = (Totals ⟕_{user_id} Profitable) ⟕_{user_id} Losing
+
+Ranked    = π_{user_id, realized_pl, total_invested,
+               (realized_pl / total_invested × 100) → roi_pct,
+               COALESCE(profitable_periods, 0) → profitable_periods,
+               COALESCE(losing_periods, 0) → losing_periods,
+               total_periods,
+               (COALESCE(profitable_periods, 0) / total_periods × 100) → consistency_pct}
+             (Combined)
+
+Result    = τ_{realized_pl ↓} (π_{username, realized_pl, total_invested, roi_pct,
+               profitable_periods, losing_periods, total_periods, consistency_pct}
+               (Ranked ⋈_{user_id = id} Users))
+}}}
+
+`Totals`/`Profitable`/`Losing` are three separate groupings of the same `Periods` relation
+because plain aggregation has no built-in "count only where X" operator; the two outer joins
+recombine them (`⟕`, not `⋈`, because a user with zero losing quarters must still appear with
+`losing_periods = 0`, not disappear from the result).
+
+== Market performance leaderboard ==
+
+=== Data requirements description ===
+
+''"Which markets were actually worth making — high volume, real price movement, real user
+interest — over a chosen period?"'' This is the "products that bring the most profit" /
+"good locations" family of question from the phase brief, translated to markets instead of
+physical products: a market with heavy volume but a dead price, or a big price swing nobody
+actually traded, are both misleading on their own; this report puts volume, trade count,
+price return and user participation side by side so a market's performance over a
+quarter/year/multi-year window can be judged as a whole, not from one number in isolation.
+Everything needed already exists: `market_trades` is the single source of truth for price and
+volume for every market ([wiki:PrototypeImplementation]),
+and `orders` is the only place a specific user is tied to a specific market
+([wiki:ERModel]) —
+`market_trades` deliberately has no `user_id` column, since it also records the market
+simulator's own fills.
+
+Given a period `[from, to)`, per market:
+
+ * '''Total volume''' = `SUM(quantity)` over its trades in the period.
+ * '''Trade count''' = `COUNT(*)` over the same trades (real fills and simulated fills alike —
+   this is activity, not just user activity).
+ * '''Average trading price''' = `AVG(price)` over the same trades.
+ * '''Market return %''' = `(last trade price − first trade price) ÷ first trade price × 100`,
+   ordering trades by `executed_at` inside the period.
+ * '''Participating users''' = `COUNT(DISTINCT user_id)` from that market's '''executed orders'''
+   in the period — the only correct source, since `market_trades` cannot answer this question
+   at all.
+
+=== Solution SQL ===
+
+Implemented as `project.report_market_performance(p_from, p_to)` in
+`schema_creation.sql`:
+
+{{{
+CREATE OR REPLACE FUNCTION project.report_market_performance(p_from timestamptz, p_to timestamptz)
+RETURNS TABLE (
+    symbol               varchar,
+    quote_currency       char(3),
+    total_volume         numeric,
+    trade_count          bigint,
+    avg_price            numeric,
+    market_return_pct    numeric,
+    participating_users  bigint
+)
+LANGUAGE sql STABLE AS $$
+    WITH trades AS (
+        SELECT
+            market_id, price, quantity, executed_at,
+            FIRST_VALUE(price) OVER w AS first_price,
+            LAST_VALUE(price)  OVER (PARTITION BY market_id ORDER BY executed_at
+                                      ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS last_price
+        FROM project.market_trades
+        WHERE executed_at >= p_from AND executed_at < p_to
+        WINDOW w AS (PARTITION BY market_id ORDER BY executed_at)
+    ),
+    market_stats AS (
+        SELECT
+            market_id,
+            SUM(quantity)    AS total_volume,
+            COUNT(*)         AS trade_count,
+            AVG(price)       AS avg_price,
+            MAX(first_price) AS first_price,
+            MAX(last_price)  AS last_price
+        FROM trades
+        GROUP BY market_id
+    ),
+    participation AS (
+        SELECT market_id, COUNT(DISTINCT user_id) AS participating_users
+        FROM project.orders
+        WHERE status = 'executed' AND executed_at >= p_from AND executed_at < p_to
+        GROUP BY market_id
+    )
+    SELECT
+        c.symbol,
+        m.quote_currency,
+        ms.total_volume,
+        ms.trade_count,
+        ROUND(ms.avg_price, 6)                                                       AS avg_price,
+        ROUND((ms.last_price - ms.first_price) / NULLIF(ms.first_price, 0) * 100, 2) AS market_return_pct,
+        COALESCE(p.participating_users, 0)                                          AS participating_users
+    FROM market_stats ms
+    JOIN project.markets m ON m.id = ms.market_id
+    JOIN project.crypto  c ON c.id = m.crypto_id
+    LEFT JOIN participation p ON p.market_id = ms.market_id
+    ORDER BY ms.total_volume DESC;
+$$;
+}}}
+
+`FIRST_VALUE`/`LAST_VALUE` pick the period's opening and closing price per market without a
+self-join; `LEFT JOIN participation` is required, not optional — a market can have trades
+from the simulator alone and legitimately zero participating users, and it must still show
+`0`, not disappear from the report.
+
+'''Verified run.''' Same seed as above (`data_load.sql` + `reports_demo_data.sql`, which also
+adds a BTC/USD uptrend and an ETH/USD downtrend across the same five quarters — see that
+file in the Demonstration data section below). Run through the CLI (`[11] Report: market performance`, `2025-01-01` to `2026-09-17`):
+
+{{{
+  Symbol  Quote        Volume    Trades       Avg Price      Return %     Users
+  -----------------------------------------------------------------------------
+  DOGE    USD      29500.0000         3        0.120583         +2.95         0
+  ADA     USD       2500.0000         3        0.450750         +1.62         0
+  SOL     USD         23.5000         3      165.283333         +1.13         0
+  ETH     USD         14.3500         8     3622.312500        -12.00         2
+  BTC     USD          3.9750         9    59447.400000        +67.85         2
+}}}
+
+BTC/USD and ETH/USD are the only two markets with historical (multi-quarter) data seeded, and
+they show it: BTC's price nearly tripled over the period (`+67.85%`), while ETH quietly lost
+`12%`. ADA/SOL/DOGE only have the few minutes of `data_load.sql`'s own recent seed trades, so
+their return numbers reflect that narrow window, and their `0` participating users is correct
+— `data_load.sql` seeds trade history for every market but only ever places an ''order'' on ETH.
+
+A price-volatility column (standard deviation of trade price) was dropped from this report
+after review — with only a handful of trades per market in most periods it read as noise
+rather than signal, and total volume plus return already carry the useful information.
+
+=== Solution Relational Algebra ===
+
+{{{
+MT_period  = σ_{executed_at ≥ from ∧ executed_at < to} (MarketTrades)
+
+Bounds     = γ_{market_id ; MIN(executed_at) → t_first, MAX(executed_at) → t_last} (MT_period)
+
+FirstPx    = π_{market_id, price → first_price}
+               (MT_period ⋈_{MT_period.market_id = Bounds.market_id
+                              ∧ executed_at = t_first} Bounds)
+LastPx     = π_{market_id, price → last_price}
+               (MT_period ⋈_{MT_period.market_id = Bounds.market_id
+                              ∧ executed_at = t_last} Bounds)
+
+Stats      = γ_{market_id ; SUM(quantity) → total_volume, COUNT(*) → trade_count,
+                AVG(price) → avg_price} (MT_period)
+
+MarketStats = (Stats ⋈_{market_id} FirstPx) ⋈_{market_id} LastPx
+
+O_period      = σ_{status = 'executed' ∧ executed_at ≥ from ∧ executed_at < to} (Orders)
+Participation = γ_{market_id ; COUNT_DISTINCT(user_id) → participating_users} (O_period)
+
+Joined = ((MarketStats ⟕_{market_id} Participation)
+            ⋈_{market_id = id} Markets) ⋈_{crypto_id = id} Crypto
+
+Result = τ_{total_volume ↓} (
+           π_{symbol, quote_currency, total_volume, trade_count, avg_price,
+              (last_price − first_price) / first_price × 100 → market_return_pct,
+              COALESCE(participating_users, 0) → participating_users}
+             (Joined) )
+}}}
+
+`FirstPx`/`LastPx` express `FIRST_VALUE`/`LAST_VALUE` — which have no classical relational-
+algebra equivalent — as an aggregation for the boundary timestamp per market followed by a
+self-join back to `MarketTrades` to recover the price at that timestamp; this is the standard
+way to express "value at the extreme of a group" in extended relational algebra.
+
+== Demonstration data ==
+
+`reports_demo_data.sql`, the optional script both verified runs above were produced with:
+
+{{{
+-- reports_demo_data.sql
+-- EduBerza - optional historical data for the P6 reports
+-- Course: Databases 2025/2026 Winter, FINKI UKIM
+--
+-- data_load.sql only seeds ~10 minutes of trade history, which is enough to
+-- demonstrate UC0001-UC0007 but not enough to show report_top_traders() or
+-- report_market_performance() doing anything interesting: everything falls
+-- into a single quarter, so "number of profitable periods" and "consistency"
+-- are trivial and "market return" has almost no history to work with.
+--
+-- This script adds five quarters of synthetic transactions, market trades and
+-- executed orders on top of an already-loaded data_load.sql, spanning
+-- 2025-07 to 2026-07, so the two P6 reports have several periods and two
+-- markets with opposite price trends to actually compare.
+--
+-- Deliberately NOT part of -init / -load-data: it only inserts into
+-- transactions, market_trades and orders, and does not touch
+-- users.available_balance/invested_balance or holdings, so it does not
+-- disturb the balances the other use cases' documented "verified run"
+-- sections depend on. Run it by hand, after data_load.sql, only to exercise
+-- the two reports:
+--
+--   psql "$DATABASE_URL" -f server/db/schema_creation.sql
+--   psql "$DATABASE_URL" -f server/db/data_load.sql
+--   psql "$DATABASE_URL" -f server/db/reports_demo_data.sql
+--
+-- Idempotent: deletes its own previously-inserted rows (tagged via
+-- description/source) before re-inserting.
+
+SET search_path TO project, public;
+
+DELETE FROM transactions  WHERE description = 'P6 demo data';
+DELETE FROM orders        WHERE id IN (
+    'e1111111-1111-1111-1111-111111111111', 'e2222222-2222-2222-2222-222222222222',
+    'e3333333-3333-3333-3333-333333333333', 'e4444444-4444-4444-4444-444444444444',
+    'e5555555-5555-5555-5555-555555555555'
+);
+DELETE FROM market_trades WHERE source = 'p6_demo';
+
+-- ============================================================================
+-- Alice: five quarterly round trips, 3 profitable / 2 losing (60% consistency)
+-- ============================================================================
+INSERT INTO transactions (user_id, type, amount, currency, created_at, description) VALUES
+    ('b1111111-1111-1111-1111-111111111111', 'buy',  -5000.0000, 'USD', '2025-07-15 10:00', 'P6 demo data'),
+    ('b1111111-1111-1111-1111-111111111111', 'sell',  5800.0000, 'USD', '2025-07-20 10:00', 'P6 demo data'),
+    ('b1111111-1111-1111-1111-111111111111', 'fee',      -5.0000, 'USD', '2025-07-20 10:00', 'P6 demo data'),
+
+    ('b1111111-1111-1111-1111-111111111111', 'buy',  -4000.0000, 'USD', '2025-10-15 10:00', 'P6 demo data'),
+    ('b1111111-1111-1111-1111-111111111111', 'sell',  3500.0000, 'USD', '2025-10-20 10:00', 'P6 demo data'),
+    ('b1111111-1111-1111-1111-111111111111', 'fee',      -5.0000, 'USD', '2025-10-20 10:00', 'P6 demo data'),
+
+    ('b1111111-1111-1111-1111-111111111111', 'buy',  -6000.0000, 'USD', '2026-01-15 10:00', 'P6 demo data'),
+    ('b1111111-1111-1111-1111-111111111111', 'sell',  6700.0000, 'USD', '2026-01-20 10:00', 'P6 demo data'),
+    ('b1111111-1111-1111-1111-111111111111', 'fee',      -5.0000, 'USD', '2026-01-20 10:00', 'P6 demo data'),
+
+    ('b1111111-1111-1111-1111-111111111111', 'buy',  -3000.0000, 'USD', '2026-04-15 10:00', 'P6 demo data'),
+    ('b1111111-1111-1111-1111-111111111111', 'sell',  2600.0000, 'USD', '2026-04-20 10:00', 'P6 demo data'),
+    ('b1111111-1111-1111-1111-111111111111', 'fee',      -5.0000, 'USD', '2026-04-20 10:00', 'P6 demo data'),
+
+    ('b1111111-1111-1111-1111-111111111111', 'buy',  -4500.0000, 'USD', '2026-07-15 10:00', 'P6 demo data'),
+    ('b1111111-1111-1111-1111-111111111111', 'sell',  5200.0000, 'USD', '2026-07-20 10:00', 'P6 demo data'),
+    ('b1111111-1111-1111-1111-111111111111', 'fee',      -5.0000, 'USD', '2026-07-20 10:00', 'P6 demo data');
+
+-- ============================================================================
+-- Bob: three quarterly round trips, all profitable (100% consistency),
+-- smaller total P/L than Alice but a higher ROI.
+-- ============================================================================
+INSERT INTO transactions (user_id, type, amount, currency, created_at, description) VALUES
+    ('b2222222-2222-2222-2222-222222222222', 'buy',  -2000.0000, 'USD', '2025-10-10 10:00', 'P6 demo data'),
+    ('b2222222-2222-2222-2222-222222222222', 'sell',  2300.0000, 'USD', '2025-10-12 10:00', 'P6 demo data'),
+    ('b2222222-2222-2222-2222-222222222222', 'fee',      -3.0000, 'USD', '2025-10-12 10:00', 'P6 demo data'),
+
+    ('b2222222-2222-2222-2222-222222222222', 'buy',  -2500.0000, 'USD', '2026-01-10 10:00', 'P6 demo data'),
+    ('b2222222-2222-2222-2222-222222222222', 'sell',  2900.0000, 'USD', '2026-01-12 10:00', 'P6 demo data'),
+    ('b2222222-2222-2222-2222-222222222222', 'fee',      -3.0000, 'USD', '2026-01-12 10:00', 'P6 demo data'),
+
+    ('b2222222-2222-2222-2222-222222222222', 'buy',  -1800.0000, 'USD', '2026-04-10 10:00', 'P6 demo data'),
+    ('b2222222-2222-2222-2222-222222222222', 'sell',  2100.0000, 'USD', '2026-04-12 10:00', 'P6 demo data'),
+    ('b2222222-2222-2222-2222-222222222222', 'fee',      -3.0000, 'USD', '2026-04-12 10:00', 'P6 demo data');
+
+-- ============================================================================
+-- Market trades: BTC/USD trending up, ETH/USD trending down, five quarters.
+-- source='p6_demo' keeps these separate from data_load.sql's own rows and
+-- from live user/bot fills so this script can clean up after itself.
+-- ============================================================================
+INSERT INTO market_trades (market_id, executed_at, price, quantity, side, source) VALUES
+    ('a1111111-1111-1111-1111-111111111111', '2025-07-15 10:00', 40000.000000, 0.500000, 'buy',  'p6_demo'),
+    ('a1111111-1111-1111-1111-111111111111', '2025-10-15 10:00', 45000.000000, 0.800000, 'buy',  'p6_demo'),
+    ('a1111111-1111-1111-1111-111111111111', '2026-01-15 10:00', 55000.000000, 1.200000, 'buy',  'p6_demo'),
+    ('a1111111-1111-1111-1111-111111111111', '2026-04-15 10:00', 60000.000000, 1.000000, 'buy',  'p6_demo'),
+
+    ('a2222222-2222-2222-2222-222222222222', '2025-07-15 10:00',  4000.000000, 3.000000, 'sell', 'p6_demo'),
+    ('a2222222-2222-2222-2222-222222222222', '2025-10-15 10:00',  3800.000000, 2.500000, 'sell', 'p6_demo'),
+    ('a2222222-2222-2222-2222-222222222222', '2026-01-15 10:00',  3600.000000, 2.000000, 'sell', 'p6_demo'),
+    ('a2222222-2222-2222-2222-222222222222', '2026-04-15 10:00',  3550.000000, 1.800000, 'sell', 'p6_demo');
+
+-- ============================================================================
+-- Executed orders: who participated in which market, across the same quarters.
+-- ============================================================================
+INSERT INTO orders (id, user_id, market_id, side, type, status, quantity, price, placed_at, executed_at) VALUES
+    ('e1111111-1111-1111-1111-111111111111', 'b1111111-1111-1111-1111-111111111111',
+     'a1111111-1111-1111-1111-111111111111', 'buy', 'market', 'executed', 0.5000, 40000.000000,
+     '2025-07-15 10:00', '2025-07-15 10:00'),
+    ('e2222222-2222-2222-2222-222222222222', 'b1111111-1111-1111-1111-111111111111',
+     'a2222222-2222-2222-2222-222222222222', 'sell', 'market', 'executed', 3.0000, 4000.000000,
+     '2025-10-15 10:00', '2025-10-15 10:00'),
+    ('e3333333-3333-3333-3333-333333333333', 'b2222222-2222-2222-2222-222222222222',
+     'a1111111-1111-1111-1111-111111111111', 'buy', 'market', 'executed', 1.2000, 55000.000000,
+     '2026-01-15 10:00', '2026-01-15 10:00'),
+    ('e4444444-4444-4444-4444-444444444444', 'b2222222-2222-2222-2222-222222222222',
+     'a1111111-1111-1111-1111-111111111111', 'buy', 'market', 'executed', 1.0000, 60000.000000,
+     '2026-04-15 10:00', '2026-04-15 10:00'),
+    ('e5555555-5555-5555-5555-555555555555', 'b3333333-3333-3333-3333-333333333333',
+     'a2222222-2222-2222-2222-222222222222', 'sell', 'market', 'executed', 2.0000, 3600.000000,
+     '2026-01-15 10:00', '2026-01-15 10:00');
+}}}
+
+== AI usage ==
+
+AI was used in this phase and is logged in full, per the course rule for P1 onward.
+
+ * '''Phase log:''' [wiki:AdvancedReportsAIUsage] — service used, what
+   the AI produced, and what I decided myself.
+
+'''Service:''' Claude Code (Anthropic), `https://claude.com/claude-code` — Claude subscription,
+model Claude Sonnet 5.
+
+'''In short:''' I specified both report questions in full — including the exact formulas for
+P/L, ROI, consistency, market return, volatility and user participation — and asked the AI to
+turn them into working SQL, wire them into the prototype as real reports, build the
+relational-algebra equivalents, and produce demonstration data rich enough to show the
+reports doing something non-trivial. In a follow-up, I asked for the price-volatility column
+to be dropped from the market performance report — see the "Follow-up — 2026-09-17" section of
+[wiki:AdvancedReportsAIUsage] for that change.
