| | 1 | = Advanced Reports AI Usage = |
| | 2 | |
| | 3 | == Name of AI service/solution that was used == |
| | 4 | |
| | 5 | '''Claude Code''' (Anthropic) |
| | 6 | |
| | 7 | * '''URL:''' `https://claude.com/claude-code` |
| | 8 | * '''Type of service/subscription:''' Claude subscription, model Claude Sonnet 5. |
| | 9 | |
| | 10 | == Final result == |
| | 11 | |
| | 12 | === Diagram === |
| | 13 | |
| | 14 | None. Both reports read `transactions`, `market_trades`, `orders`, `markets`, `crypto` and |
| | 15 | `users` exactly as they already existed after |
| | 16 | Normalization — no attribute or relation was missing, |
| | 17 | so ERModel and |
| | 18 | !RelationalDesign needed no changes and there is |
| | 19 | no new diagram for this phase. This is stated explicitly rather than left implicit because the |
| | 20 | phase rubric specifically calls out modifying the design as the fallback when a good report |
| | 21 | idea can't be answered by the data on hand — it wasn't needed here. |
| | 22 | |
| | 23 | === Results in details / description === |
| | 24 | |
| | 25 | The AI: |
| | 26 | |
| | 27 | * Turned my two fully-specified report questions (the exact P/L, ROI, consistency, volume, |
| | 28 | return, volatility and participation formulas were mine) into two single-statement SQL |
| | 29 | queries, each wrapped as a `LANGUAGE sql STABLE` function |
| | 30 | (`project.report_top_traders`, `project.report_market_performance`) in |
| | 31 | `schema_creation.sql`, so the phase's "just one SQL |
| | 32 | query" requirement is met by the query text itself, while still giving the prototype a |
| | 33 | clean, parameterised, named thing to call. |
| | 34 | |
| | 35 | The two functions, from `schema_creation.sql`: |
| | 36 | |
| | 37 | {{{ |
| | 38 | -- report_top_traders: realized trading performance per user over [p_from, p_to), |
| | 39 | -- bucketed into quarters to measure how consistently each user was profitable. |
| | 40 | CREATE OR REPLACE FUNCTION project.report_top_traders(p_from timestamptz, p_to timestamptz) |
| | 41 | RETURNS TABLE ( |
| | 42 | username varchar, |
| | 43 | realized_pl numeric, |
| | 44 | total_invested numeric, |
| | 45 | roi_pct numeric, |
| | 46 | profitable_periods bigint, |
| | 47 | losing_periods bigint, |
| | 48 | total_periods bigint, |
| | 49 | consistency_pct numeric |
| | 50 | ) |
| | 51 | LANGUAGE sql STABLE AS $$ |
| | 52 | WITH period_pl AS ( |
| | 53 | SELECT |
| | 54 | t.user_id, |
| | 55 | date_trunc('quarter', t.created_at) AS period, |
| | 56 | SUM(t.amount) AS period_pl, |
| | 57 | SUM(t.amount) FILTER (WHERE t.type = 'buy') AS period_buy |
| | 58 | FROM project.transactions t |
| | 59 | WHERE t.type IN ('buy', 'sell', 'fee') |
| | 60 | AND t.created_at >= p_from |
| | 61 | AND t.created_at < p_to |
| | 62 | GROUP BY t.user_id, date_trunc('quarter', t.created_at) |
| | 63 | ) |
| | 64 | SELECT |
| | 65 | u.username, |
| | 66 | SUM(pp.period_pl) AS realized_pl, |
| | 67 | ABS(SUM(pp.period_buy)) AS total_invested, |
| | 68 | ROUND(SUM(pp.period_pl) / NULLIF(ABS(SUM(pp.period_buy)), 0) * 100, 2) AS roi_pct, |
| | 69 | COUNT(*) FILTER (WHERE pp.period_pl > 0) AS profitable_periods, |
| | 70 | COUNT(*) FILTER (WHERE pp.period_pl < 0) AS losing_periods, |
| | 71 | COUNT(*) AS total_periods, |
| | 72 | ROUND(COUNT(*) FILTER (WHERE pp.period_pl > 0)::numeric |
| | 73 | / NULLIF(COUNT(*), 0) * 100, 2) AS consistency_pct |
| | 74 | FROM period_pl pp |
| | 75 | JOIN project.users u ON u.id = pp.user_id |
| | 76 | GROUP BY u.id, u.username |
| | 77 | ORDER BY realized_pl DESC; |
| | 78 | $$; |
| | 79 | |
| | 80 | -- report_market_performance: trading activity and price behaviour per market |
| | 81 | -- over [p_from, p_to). Volume/trade-count/price stats come from market_trades |
| | 82 | -- (the complete tape — user fills and simulated fills alike); participating |
| | 83 | -- users can only come from orders, since market_trades has no user_id column. |
| | 84 | CREATE OR REPLACE FUNCTION project.report_market_performance(p_from timestamptz, p_to timestamptz) |
| | 85 | RETURNS TABLE ( |
| | 86 | symbol varchar, |
| | 87 | quote_currency char(3), |
| | 88 | total_volume numeric, |
| | 89 | trade_count bigint, |
| | 90 | avg_price numeric, |
| | 91 | market_return_pct numeric, |
| | 92 | participating_users bigint |
| | 93 | ) |
| | 94 | LANGUAGE sql STABLE AS $$ |
| | 95 | WITH trades AS ( |
| | 96 | SELECT |
| | 97 | market_id, price, quantity, executed_at, |
| | 98 | FIRST_VALUE(price) OVER w AS first_price, |
| | 99 | LAST_VALUE(price) OVER (PARTITION BY market_id ORDER BY executed_at |
| | 100 | ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS last_price |
| | 101 | FROM project.market_trades |
| | 102 | WHERE executed_at >= p_from AND executed_at < p_to |
| | 103 | WINDOW w AS (PARTITION BY market_id ORDER BY executed_at) |
| | 104 | ), |
| | 105 | market_stats AS ( |
| | 106 | SELECT |
| | 107 | market_id, |
| | 108 | SUM(quantity) AS total_volume, |
| | 109 | COUNT(*) AS trade_count, |
| | 110 | AVG(price) AS avg_price, |
| | 111 | MAX(first_price) AS first_price, |
| | 112 | MAX(last_price) AS last_price |
| | 113 | FROM trades |
| | 114 | GROUP BY market_id |
| | 115 | ), |
| | 116 | participation AS ( |
| | 117 | SELECT market_id, COUNT(DISTINCT user_id) AS participating_users |
| | 118 | FROM project.orders |
| | 119 | WHERE status = 'executed' AND executed_at >= p_from AND executed_at < p_to |
| | 120 | GROUP BY market_id |
| | 121 | ) |
| | 122 | SELECT |
| | 123 | c.symbol, |
| | 124 | m.quote_currency, |
| | 125 | ms.total_volume, |
| | 126 | ms.trade_count, |
| | 127 | ROUND(ms.avg_price, 6) AS avg_price, |
| | 128 | ROUND((ms.last_price - ms.first_price) / NULLIF(ms.first_price, 0) * 100, 2) AS market_return_pct, |
| | 129 | COALESCE(p.participating_users, 0) AS participating_users |
| | 130 | FROM market_stats ms |
| | 131 | JOIN project.markets m ON m.id = ms.market_id |
| | 132 | JOIN project.crypto c ON c.id = m.crypto_id |
| | 133 | LEFT JOIN participation p ON p.market_id = ms.market_id |
| | 134 | ORDER BY ms.total_volume DESC; |
| | 135 | $$; |
| | 136 | }}} |
| | 137 | |
| | 138 | * Wired both into the running CLI as real menu options — `server/reports.go`, options |
| | 139 | `[10]`/`[11]` in `server/cli.go` — rather than leaving them as documentation-only SQL, per |
| | 140 | the phase's own framing ("used as reports within your application"). |
| | 141 | * Wrote the relational-algebra equivalent of each query, including how to express |
| | 142 | `FIRST_VALUE`/`LAST_VALUE` (which have no classical RA equivalent) as an aggregation for the |
| | 143 | boundary timestamp followed by a self-join, and how to express `FILTER (WHERE …)`-style |
| | 144 | conditional counts as separate groupings recombined with left outer joins. |
| | 145 | * Noticed that the existing `data_load.sql` seed data (a few minutes of trade history) cannot |
| | 146 | demonstrate either report meaningfully — everything falls into one quarter, so "consistency" |
| | 147 | and "market return over time" have nothing to show — and wrote |
| | 148 | `reports_demo_data.sql`, an optional, separate, |
| | 149 | idempotent script adding five quarters of synthetic transactions, market trades and executed |
| | 150 | orders, deliberately excluded from `-init`/`-load-data` so it cannot disturb the balances the |
| | 151 | other use cases' documented "verified run" sections depend on. |
| | 152 | |
| | 153 | `reports_demo_data.sql`: |
| | 154 | |
| | 155 | {{{ |
| | 156 | -- reports_demo_data.sql |
| | 157 | -- EduBerza - optional historical data for the P6 reports |
| | 158 | -- Course: Databases 2025/2026 Winter, FINKI UKIM |
| | 159 | -- |
| | 160 | -- data_load.sql only seeds ~10 minutes of trade history, which is enough to |
| | 161 | -- demonstrate UC0001-UC0007 but not enough to show report_top_traders() or |
| | 162 | -- report_market_performance() doing anything interesting: everything falls |
| | 163 | -- into a single quarter, so "number of profitable periods" and "consistency" |
| | 164 | -- are trivial and "market return" has almost no history to work with. |
| | 165 | -- |
| | 166 | -- This script adds five quarters of synthetic transactions, market trades and |
| | 167 | -- executed orders on top of an already-loaded data_load.sql, spanning |
| | 168 | -- 2025-07 to 2026-07, so the two P6 reports have several periods and two |
| | 169 | -- markets with opposite price trends to actually compare. |
| | 170 | -- |
| | 171 | -- Deliberately NOT part of -init / -load-data: it only inserts into |
| | 172 | -- transactions, market_trades and orders, and does not touch |
| | 173 | -- users.available_balance/invested_balance or holdings, so it does not |
| | 174 | -- disturb the balances the other use cases' documented "verified run" |
| | 175 | -- sections depend on. Run it by hand, after data_load.sql, only to exercise |
| | 176 | -- the two reports: |
| | 177 | -- |
| | 178 | -- psql "$DATABASE_URL" -f server/db/schema_creation.sql |
| | 179 | -- psql "$DATABASE_URL" -f server/db/data_load.sql |
| | 180 | -- psql "$DATABASE_URL" -f server/db/reports_demo_data.sql |
| | 181 | -- |
| | 182 | -- Idempotent: deletes its own previously-inserted rows (tagged via |
| | 183 | -- description/source) before re-inserting. |
| | 184 | |
| | 185 | SET search_path TO project, public; |
| | 186 | |
| | 187 | DELETE FROM transactions WHERE description = 'P6 demo data'; |
| | 188 | DELETE FROM orders WHERE id IN ( |
| | 189 | 'e1111111-1111-1111-1111-111111111111', 'e2222222-2222-2222-2222-222222222222', |
| | 190 | 'e3333333-3333-3333-3333-333333333333', 'e4444444-4444-4444-4444-444444444444', |
| | 191 | 'e5555555-5555-5555-5555-555555555555' |
| | 192 | ); |
| | 193 | DELETE FROM market_trades WHERE source = 'p6_demo'; |
| | 194 | |
| | 195 | -- ============================================================================ |
| | 196 | -- Alice: five quarterly round trips, 3 profitable / 2 losing (60% consistency) |
| | 197 | -- ============================================================================ |
| | 198 | INSERT INTO transactions (user_id, type, amount, currency, created_at, description) VALUES |
| | 199 | ('b1111111-1111-1111-1111-111111111111', 'buy', -5000.0000, 'USD', '2025-07-15 10:00', 'P6 demo data'), |
| | 200 | ('b1111111-1111-1111-1111-111111111111', 'sell', 5800.0000, 'USD', '2025-07-20 10:00', 'P6 demo data'), |
| | 201 | ('b1111111-1111-1111-1111-111111111111', 'fee', -5.0000, 'USD', '2025-07-20 10:00', 'P6 demo data'), |
| | 202 | |
| | 203 | ('b1111111-1111-1111-1111-111111111111', 'buy', -4000.0000, 'USD', '2025-10-15 10:00', 'P6 demo data'), |
| | 204 | ('b1111111-1111-1111-1111-111111111111', 'sell', 3500.0000, 'USD', '2025-10-20 10:00', 'P6 demo data'), |
| | 205 | ('b1111111-1111-1111-1111-111111111111', 'fee', -5.0000, 'USD', '2025-10-20 10:00', 'P6 demo data'), |
| | 206 | |
| | 207 | ('b1111111-1111-1111-1111-111111111111', 'buy', -6000.0000, 'USD', '2026-01-15 10:00', 'P6 demo data'), |
| | 208 | ('b1111111-1111-1111-1111-111111111111', 'sell', 6700.0000, 'USD', '2026-01-20 10:00', 'P6 demo data'), |
| | 209 | ('b1111111-1111-1111-1111-111111111111', 'fee', -5.0000, 'USD', '2026-01-20 10:00', 'P6 demo data'), |
| | 210 | |
| | 211 | ('b1111111-1111-1111-1111-111111111111', 'buy', -3000.0000, 'USD', '2026-04-15 10:00', 'P6 demo data'), |
| | 212 | ('b1111111-1111-1111-1111-111111111111', 'sell', 2600.0000, 'USD', '2026-04-20 10:00', 'P6 demo data'), |
| | 213 | ('b1111111-1111-1111-1111-111111111111', 'fee', -5.0000, 'USD', '2026-04-20 10:00', 'P6 demo data'), |
| | 214 | |
| | 215 | ('b1111111-1111-1111-1111-111111111111', 'buy', -4500.0000, 'USD', '2026-07-15 10:00', 'P6 demo data'), |
| | 216 | ('b1111111-1111-1111-1111-111111111111', 'sell', 5200.0000, 'USD', '2026-07-20 10:00', 'P6 demo data'), |
| | 217 | ('b1111111-1111-1111-1111-111111111111', 'fee', -5.0000, 'USD', '2026-07-20 10:00', 'P6 demo data'); |
| | 218 | |
| | 219 | -- ============================================================================ |
| | 220 | -- Bob: three quarterly round trips, all profitable (100% consistency), |
| | 221 | -- smaller total P/L than Alice but a higher ROI. |
| | 222 | -- ============================================================================ |
| | 223 | INSERT INTO transactions (user_id, type, amount, currency, created_at, description) VALUES |
| | 224 | ('b2222222-2222-2222-2222-222222222222', 'buy', -2000.0000, 'USD', '2025-10-10 10:00', 'P6 demo data'), |
| | 225 | ('b2222222-2222-2222-2222-222222222222', 'sell', 2300.0000, 'USD', '2025-10-12 10:00', 'P6 demo data'), |
| | 226 | ('b2222222-2222-2222-2222-222222222222', 'fee', -3.0000, 'USD', '2025-10-12 10:00', 'P6 demo data'), |
| | 227 | |
| | 228 | ('b2222222-2222-2222-2222-222222222222', 'buy', -2500.0000, 'USD', '2026-01-10 10:00', 'P6 demo data'), |
| | 229 | ('b2222222-2222-2222-2222-222222222222', 'sell', 2900.0000, 'USD', '2026-01-12 10:00', 'P6 demo data'), |
| | 230 | ('b2222222-2222-2222-2222-222222222222', 'fee', -3.0000, 'USD', '2026-01-12 10:00', 'P6 demo data'), |
| | 231 | |
| | 232 | ('b2222222-2222-2222-2222-222222222222', 'buy', -1800.0000, 'USD', '2026-04-10 10:00', 'P6 demo data'), |
| | 233 | ('b2222222-2222-2222-2222-222222222222', 'sell', 2100.0000, 'USD', '2026-04-12 10:00', 'P6 demo data'), |
| | 234 | ('b2222222-2222-2222-2222-222222222222', 'fee', -3.0000, 'USD', '2026-04-12 10:00', 'P6 demo data'); |
| | 235 | |
| | 236 | -- ============================================================================ |
| | 237 | -- Market trades: BTC/USD trending up, ETH/USD trending down, five quarters. |
| | 238 | -- source='p6_demo' keeps these separate from data_load.sql's own rows and |
| | 239 | -- from live user/bot fills so this script can clean up after itself. |
| | 240 | -- ============================================================================ |
| | 241 | INSERT INTO market_trades (market_id, executed_at, price, quantity, side, source) VALUES |
| | 242 | ('a1111111-1111-1111-1111-111111111111', '2025-07-15 10:00', 40000.000000, 0.500000, 'buy', 'p6_demo'), |
| | 243 | ('a1111111-1111-1111-1111-111111111111', '2025-10-15 10:00', 45000.000000, 0.800000, 'buy', 'p6_demo'), |
| | 244 | ('a1111111-1111-1111-1111-111111111111', '2026-01-15 10:00', 55000.000000, 1.200000, 'buy', 'p6_demo'), |
| | 245 | ('a1111111-1111-1111-1111-111111111111', '2026-04-15 10:00', 60000.000000, 1.000000, 'buy', 'p6_demo'), |
| | 246 | |
| | 247 | ('a2222222-2222-2222-2222-222222222222', '2025-07-15 10:00', 4000.000000, 3.000000, 'sell', 'p6_demo'), |
| | 248 | ('a2222222-2222-2222-2222-222222222222', '2025-10-15 10:00', 3800.000000, 2.500000, 'sell', 'p6_demo'), |
| | 249 | ('a2222222-2222-2222-2222-222222222222', '2026-01-15 10:00', 3600.000000, 2.000000, 'sell', 'p6_demo'), |
| | 250 | ('a2222222-2222-2222-2222-222222222222', '2026-04-15 10:00', 3550.000000, 1.800000, 'sell', 'p6_demo'); |
| | 251 | |
| | 252 | -- ============================================================================ |
| | 253 | -- Executed orders: who participated in which market, across the same quarters. |
| | 254 | -- ============================================================================ |
| | 255 | INSERT INTO orders (id, user_id, market_id, side, type, status, quantity, price, placed_at, executed_at) VALUES |
| | 256 | ('e1111111-1111-1111-1111-111111111111', 'b1111111-1111-1111-1111-111111111111', |
| | 257 | 'a1111111-1111-1111-1111-111111111111', 'buy', 'market', 'executed', 0.5000, 40000.000000, |
| | 258 | '2025-07-15 10:00', '2025-07-15 10:00'), |
| | 259 | ('e2222222-2222-2222-2222-222222222222', 'b1111111-1111-1111-1111-111111111111', |
| | 260 | 'a2222222-2222-2222-2222-222222222222', 'sell', 'market', 'executed', 3.0000, 4000.000000, |
| | 261 | '2025-10-15 10:00', '2025-10-15 10:00'), |
| | 262 | ('e3333333-3333-3333-3333-333333333333', 'b2222222-2222-2222-2222-222222222222', |
| | 263 | 'a1111111-1111-1111-1111-111111111111', 'buy', 'market', 'executed', 1.2000, 55000.000000, |
| | 264 | '2026-01-15 10:00', '2026-01-15 10:00'), |
| | 265 | ('e4444444-4444-4444-4444-444444444444', 'b2222222-2222-2222-2222-222222222222', |
| | 266 | 'a1111111-1111-1111-1111-111111111111', 'buy', 'market', 'executed', 1.0000, 60000.000000, |
| | 267 | '2026-04-15 10:00', '2026-04-15 10:00'), |
| | 268 | ('e5555555-5555-5555-5555-555555555555', 'b3333333-3333-3333-3333-333333333333', |
| | 269 | 'a2222222-2222-2222-2222-222222222222', 'sell', 'market', 'executed', 2.0000, 3600.000000, |
| | 270 | '2026-01-15 10:00', '2026-01-15 10:00'); |
| | 271 | }}} |
| | 272 | |
| | 273 | * Ran both reports against a live PostgreSQL 16 database with that demo data loaded, through |
| | 274 | the actual CLI, and used the real output (including a run where alice's seeded quarter |
| | 275 | interacted with a pre-existing `data_load.sql` transaction and flipped a profitable quarter |
| | 276 | into a loss) as the verified evidence in !AdvancedReports, rather |
| | 277 | than inventing example numbers. |
| | 278 | |
| | 279 | == Summary of AI involvement == |
| | 280 | |
| | 281 | || ||= This session — 2026-09-16 =|| |
| | 282 | ||= What I brought =|| The phase rubric, plus both report questions fully specified down to the exact aggregate formulas || |
| | 283 | ||= What the AI did =|| Wrote the SQL, wrote the relational algebra, wired the reports into the CLI, designed and ran the demonstration data, verified everything against a live database || |
| | 284 | ||= What I decided =|| To keep both reports as SQL functions rather than plain ad-hoc queries so they are actually usable from the application; to accept the AI's synthetic multi-quarter demo dataset rather than wait for enough real usage history to accumulate || |
| | 285 | |
| | 286 | The two ideas and their formulas were mine, specified in enough detail (P/L as the sum of |
| | 287 | buy+sell+fee transactions, ROI relative to total buys, consistency as a share of profitable |
| | 288 | quarters, market return as first-vs-last trade price, volatility as price standard deviation, |
| | 289 | participation from orders rather than trades) that there was no separate "AI alternative |
| | 290 | idea" to borrow from and document a change against, unlike the more open-ended P1–P3 phases — |
| | 291 | the AI's job here was implementation and verification of a fully-specified design, which is |
| | 292 | what is logged above and in the prompt below. |
| | 293 | |
| | 294 | == Entire AI usage log == |
| | 295 | |
| | 296 | === 2026-09-16 === |
| | 297 | |
| | 298 | '''Intent:''' hand over the P6 rubric together with both report ideas, fully specified, and |
| | 299 | have the whole phase — SQL, relational algebra, prototype integration, and demonstration data |
| | 300 | — produced and verified in one pass. |
| | 301 | |
| | 302 | '''Prompt (student, verbatim):''' |
| | 303 | > Phase P6: Complex DB Reports (SQL, Stored Procedures, Relational Algebra) |
| | 304 | > [the full phase rubric was pasted: 2 complex analytical reports solvable each with one SQL |
| | 305 | > query, usable as reports within the application, with a note that helper views/functions/ |
| | 306 | > procedures are acceptable when pure SQL isn't enough, that the design should be extended if |
| | 307 | > a good idea needs data that doesn't exist yet, a requirement for the corresponding relational |
| | 308 | > algebra, the exact `AdvancedReports`/`AdvancedReportsAIUsage` wiki templates, and the phase's |
| | 309 | > AI-use rules] |
| | 310 | > |
| | 311 | > I will describe for you the 2 more complex sql queries: |
| | 312 | > 1. Find the users who performed the best in a selected quarter, year, or multi-year period |
| | 313 | > based on their realized trading performance, and show their total profit/loss, total |
| | 314 | > amount invested, ROI, number of profitable and losing periods, and consistency of |
| | 315 | > returns. Calculate realized P/L as SUM(sell transactions + buy transactions + fee |
| | 316 | > transactions), calculate ROI as realized P/L / absolute value of total buy transactions × |
| | 317 | > 100, and calculate consistency as profitable periods / total periods × 100. |
| | 318 | > 2. Find which cryptocurrency markets performed best during a selected quarter, year, or |
| | 319 | > multi-year period based on trading activity and price behavior, and report the markets |
| | 320 | > with the highest trading volume, number of trades, number of participating users, and |
| | 321 | > price return. Calculate total volume as SUM(trade quantity), average trading price as |
| | 322 | > AVG(price), market return as (last trade price − first trade price) / first trade price × |
| | 323 | > 100, price volatility as standard deviation of trade prices, and user participation as |
| | 324 | > COUNT(DISTINCT user_id) from the related executed orders. |
| | 325 | |
| | 326 | '''Response (AI, summarised):''' |
| | 327 | * Confirmed both report questions were answerable from the existing schema with no new |
| | 328 | columns or tables, and said so explicitly rather than silently skipping that check. |
| | 329 | * Wrote `report_top_traders` and `report_market_performance` as SQL functions, added to |
| | 330 | `schema_creation.sql` under a new `REPORTS (P6)` section. |
| | 331 | * Wrote `server/reports.go` (`ShowTopTraders`, `ShowMarketPerformance`, a shared |
| | 332 | `promptPeriod` helper) and added menu options `[10]`/`[11]` to `server/cli.go`. |
| | 333 | * Wrote `server/db/reports_demo_data.sql` for a richer, multi-quarter demonstration, and |
| | 334 | documented in its own header exactly why it is optional and what it deliberately does not |
| | 335 | touch (user balances, holdings). |
| | 336 | * Built the prototype, ran both reports against the live database with the demo data loaded, |
| | 337 | cross-checked the SQL output against hand-computed expected values for both seeded users, |
| | 338 | and used that real output as the verified evidence. |
| | 339 | * Wrote out the relational-algebra derivation for each query and !AdvancedReports. |
| | 340 | |
| | 341 | '''What I decided:''' to keep the demo dataset out of `-init`/`-load-data` rather than merge it |
| | 342 | into `data_load.sql`, since the other phases' documented expected values (specific balances in |
| | 343 | !BuildInstructions) depend on the seed data staying |
| | 344 | exactly as it is. |
| | 345 | |
| | 346 | > '''Student action required.''' Read !AdvancedReports end to end |
| | 347 | > before the defense, and be ready to compute one period's realized P/L or one market's return |
| | 348 | > by hand from the raw `transactions`/`market_trades` rows — the numbers in the verified run |
| | 349 | > are real output, not invented, so they can be checked against |
| | 350 | > `reports_demo_data.sql` (shown above) directly. Append any further |
| | 351 | > prompts here if you ask for revisions. |
| | 352 | |
| | 353 | === Follow-up — 2026-09-17 === |
| | 354 | |
| | 355 | '''Intent:''' simplify the market performance report after seeing it run — with only a handful |
| | 356 | of trades per market in most periods, price volatility read as noise rather than a useful |
| | 357 | signal. |
| | 358 | |
| | 359 | '''Prompt (student, verbatim):''' |
| | 360 | > Can you tell me the exact database_url so I can execute the schema creating and the data_load? |
| | 361 | > |
| | 362 | > From the Market Performance can we remove Volatility, I don't think that is that useful, also |
| | 363 | > can you tell me what is users column? |
| | 364 | |
| | 365 | '''Response (AI, summarised):''' |
| | 366 | * Gave the local dev connection string (`postgresql://bp_project:1234@localhost:5433/bp_database`, |
| | 367 | from `.env`) and explained `participating_users` is `COUNT(DISTINCT user_id)` from that |
| | 368 | market's executed orders, not from `market_trades` (which has no `user_id`). |
| | 369 | * Removed `price_volatility`/`STDDEV(price)` from `report_market_performance()` in |
| | 370 | `schema_creation.sql`, from its `RETURNS TABLE` and its `SELECT`, and from the corresponding |
| | 371 | column in `server/reports.go`'s `ShowMarketPerformance`. |
| | 372 | * Updated the relational algebra (`Stats`, `Result`) and the SQL listing, verified run output, |
| | 373 | and prose in !AdvancedReports to match, and added a short note |
| | 374 | explaining why the column was dropped. |
| | 375 | * Rebuilt, re-ran `-init` and `reports_demo_data.sql` against the live database, and |
| | 376 | re-verified the market performance report through the actual CLI before and after the |
| | 377 | change to confirm only the one column disappeared and every other number is unchanged. |
| | 378 | |
| | 379 | '''What I decided:''' to drop the column entirely rather than keep it computed-but-hidden, |
| | 380 | since an unused computation left in the query is exactly the kind of thing that should not |
| | 381 | survive a review. |