{
 "license": "CC-BY-NC-4.0; derived from the MerRec dataset, Copyright Mercari, Inc.; see LICENSE-MERREC.md in this directory",
 "name": "merrec-agent-session",
 "recorded_at_utc": "2026-10-15T15:01:09Z",
 "method": "Statements written in order by an AI agent (Claude, in Claude Code) on 2026-10-12 against a freshly started MerRec scale server over Arrow Flight SQL, each written after reading the previous response, following the GPU UDTF discovery guide. On 2026-10-15 the same statements were replayed in the same order against a freshly started server built from commit d4b48c569, with both source Parquet files in the operating-system page cache; elapsed times, query ids, execution details and rows are from that replay. Result rows of steps 1, 3, 4 and 5 are identical to the 2026-10-12 session; step 2 returns the descriptor in its current shape. The probes were sent after the session to record the planning-time errors for two wrong column names.",
 "server": {
  "config": "fixture/demo/merrec/scripts/scale/server.toml",
  "execution_mode": "native_required",
  "binary_sha256": "f11352d8a2bb6873bf466b15698bbfb67d797a55d1a1dccbfb6713ca0e422969"
 },
 "dataset": "MerRec, 1,268,092,738 events, May through October 2023",
 "steps": [
  {
   "step": 1,
   "intent": "Which graph functions can rank brands around a seed?",
   "sql": "SELECT function_name, summary\nFROM gpu_list_functions()\nWHERE provider = 'cugraph' AND (function_name LIKE '%pagerank%' OR function_name LIKE '%jaccard%')\nORDER BY function_name",
   "status": "ok",
   "elapsed_s": 0.0041826339438557625,
   "source_cache_resident_before": {
    "items.parquet": 1.0,
    "events.parquet": 1.0
   },
   "query_id": "ba9821ca-b67b-4254-8140-2ec28403e297",
   "rows": [
    {
     "function_name": "cugraph_jaccard",
     "summary": "Compare explicit vertex pairs by dividing the size of their shared-neighbor intersection by the size of their neighbor union."
    },
    {
     "function_name": "cugraph_pagerank",
     "summary": "Rank vertices by the stationary probability of a damped random walk that follows outgoing edges."
    },
    {
     "function_name": "cugraph_personalized_pagerank",
     "summary": "Rank vertices with PageRank while biasing random-walk restarts toward explicitly weighted personalization vertices."
    }
   ]
  },
  {
   "step": 2,
   "intent": "What does personalized PageRank take, and what does it return?",
   "sql": "SELECT signature, relation_roles_json, result_schemas_json\nFROM gpu_describe_function('cugraph_personalized_pagerank')",
   "status": "ok",
   "elapsed_s": 0.0027022899594157934,
   "source_cache_resident_before": {
    "items.parquet": 1.0,
    "events.parquet": 1.0
   },
   "query_id": "21a19e2a-2b3b-4143-b71d-bc023511c27f",
   "rows": [
    {
     "signature": "cugraph_personalized_pagerank(edges => (relation subquery), directed => value, renumber => value, construction_policy => value, personalization => (relation subquery), alpha => value, epsilon => value, max_iterations => value)",
     "relation_roles_json": "[{\"name\":\"edges\",\"required\":true,\"description\":\"edge relation with canonical src and dst columns, plus optional weight and edge_id columns\",\"fields\":[{\"name\":\"src\",\"required\":true,\"type\":\"vertex_id\",\"data_types\":[\"Int32\",\"Int64\",\"Utf8\",\"LargeUtf8\",\"Utf8View\"],\"description\":\"source vertex identifier\"},{\"name\":\"dst\",\"required\":true,\"type\":\"vertex_id\",\"data_types\":[\"Int32\",\"Int64\",\"Utf8\",\"LargeUtf8\",\"Utf8View\"],\"description\":\"destination vertex identifier\"},{\"name\":\"weight\",\"required\":false,\"type\":\"numeric\",\"data_types\":[\"Float32\",\"Float64\"],\"description\":\"optional edge weight\"},{\"name\":\"edge_id\",\"required\":false,\"type\":\"integer_edge_id\",\"data_types\":[\"Int32\",\"Int64\"],\"description\":\"optional edge identifier\"}],\"vertex_id_contract\":{\"numeric_endpoint_types\":[\"Int32\",\"Int64\"],\"mapped_numeric_endpoint_types\":[],\"logical_string_endpoint_types\":[\"Utf8\",\"LargeUtf8\",\"Utf8View\"],\"logical_string_output_type\":\"Utf8\",\"native_logical_mapping_type\":\"Int64\",\"edge_id_supported_for_logical_string\":false,\"call_specific_authority\":\"gpu_validate_call\"}},{\"name\":\"personalization\",\"required\":true,\"description\":\"personalization relation with vertex and numeric value columns\",\"fields\":[{\"name\":\"vertex\",\"required\":true,\"type\":\"vertex_id\",\"data_types\":[\"Int32\",\"Int64\",\"Utf8\",\"LargeUtf8\",\"Utf8View\"],\"description\":\"personalization vertex identifier\"},{\"name\":\"value\",\"required\":true,\"type\":\"numeric\",\"data_types\":[\"Float32\",\"Float64\"],\"description\":\"personalization value\"}]}]",
     "result_schemas_json": "{\"default_schema\":\"default\",\"schemas\":{\"default\":{\"fields\":[{\"name\":\"vertex\",\"data_type\":\"Int64|Utf8\",\"nullable\":false},{\"name\":\"value\",\"data_type\":\"Float64\",\"nullable\":false}]}},\"call_specific_authority\":\"gpu_validate_call\",\"note\":\"Generic registry schemas; run gpu_validate_call for the concrete table-specific output schema.\",\"field_descriptions\":[{\"name\":\"vertex\",\"description\":\"Vertex receiving the PageRank score.\"},{\"name\":\"value\",\"description\":\"PageRank score for the vertex.\"}]}"
    }
   ]
  },
  {
   "step": 3,
   "intent": "Which vertex is Barbie? Look up the brand id to seed from",
   "sql": "SELECT brand_id, COUNT(*) AS items\nFROM merrec_items\nWHERE brand_name = 'Barbie'\nGROUP BY brand_id\nORDER BY items DESC",
   "status": "ok",
   "elapsed_s": 0.5186802430544049,
   "source_cache_resident_before": {
    "items.parquet": 1.0,
    "events.parquet": 1.0
   },
   "query_id": "4addcf9e-6958-44f0-8785-ba682b563b8e",
   "rows": [
    {
     "brand_id": 2595,
     "items": 221444
    }
   ]
  },
  {
   "step": 4,
   "intent": "Before spending GPU time: will the whole query run on the GPU?",
   "sql": "EXPLAIN GPU\nWITH likes AS (\n  SELECT DISTINCT -(e.user_id + 1) AS src, CAST(i.brand_id AS BIGINT) AS dst,\n         e.event_time >= TIMESTAMP '2023-07-01 00:00:00' AS after_release\n  FROM merrec_events e JOIN merrec_items i ON i.item_id = e.item_id\n  WHERE e.event_type = 'item_like' AND i.brand_id <> 0\n    AND e.event_time >= TIMESTAMP '2023-05-01 00:00:00'\n    AND e.event_time < TIMESTAMP '2023-09-01 00:00:00'\n), lift_before AS (\n  SELECT p.vertex, p.value / r.value AS lift\n  FROM cugraph_personalized_pagerank(\n    edges => (SELECT src, dst FROM likes WHERE NOT after_release),\n    personalization => (SELECT 2595 AS vertex, 1.0 AS value),\n    directed => false) p\n  JOIN cugraph_pagerank(\n    edges => (SELECT src, dst FROM likes WHERE NOT after_release), directed => false) r\n    ON r.vertex = p.vertex\n), lift_after AS (\n  SELECT p.vertex, p.value / r.value AS lift\n  FROM cugraph_personalized_pagerank(\n    edges => (SELECT src, dst FROM likes WHERE after_release),\n    personalization => (SELECT 2595 AS vertex, 1.0 AS value),\n    directed => false) p\n  JOIN cugraph_pagerank(\n    edges => (SELECT src, dst FROM likes WHERE after_release), directed => false) r\n    ON r.vertex = p.vertex\n), fans AS (\n  SELECT dst AS brand_id,\n         SUM(CASE WHEN after_release THEN 0 ELSE 1 END) AS fans_before,\n         SUM(CASE WHEN after_release THEN 1 ELSE 0 END) AS fans_after\n  FROM likes GROUP BY dst\n), brands AS (\n  SELECT CAST(brand_id AS BIGINT) AS brand_id, MIN(brand_name) AS brand_name\n  FROM merrec_items WHERE brand_id <> 0 GROUP BY brand_id\n)\nSELECT b.brand_name, f.fans_before, f.fans_after,\n       lb.lift AS lift_before, la.lift AS lift_after, la.lift / lb.lift AS lift_change\nFROM lift_after la\nJOIN lift_before lb ON lb.vertex = la.vertex\nJOIN fans f ON f.brand_id = la.vertex\nJOIN brands b ON b.brand_id = la.vertex\nWHERE la.vertex > 0 AND la.vertex <> 2595\n  AND f.fans_before >= 1000 AND f.fans_after >= 1000\nORDER BY lift_change DESC, b.brand_name\nLIMIT 25",
   "status": "ok",
   "elapsed_s": 0.08838822110556066,
   "source_cache_resident_before": {
    "items.parquet": 1.0,
    "events.parquet": 1.0
   },
   "query_id": "ca241ffd-f4db-4e1f-bdc5-0974272abf1d",
   "summary": {
    "gpu_path": "native",
    "gpu_fragments": 15,
    "cpu_boundaries": 0,
    "outcome": "accepted_replaced"
   },
   "candidates": [
    {
     "candidate_family": "sort_fetch_hash_join_input",
     "outcome": "selected"
    },
    {
     "candidate_family": "projected_global_hash_join_aggregate",
     "outcome": "selected"
    },
    {
     "candidate_family": "other_literal_input",
     "outcome": "selected"
    },
    {
     "candidate_family": "projected_global_hash_join_aggregate",
     "outcome": "selected"
    },
    {
     "candidate_family": "projected_global_hash_join_aggregate",
     "outcome": "selected"
    },
    {
     "candidate_family": "other_literal_input",
     "outcome": "selected"
    },
    {
     "candidate_family": "projected_global_hash_join_aggregate",
     "outcome": "selected"
    }
   ]
  },
  {
   "step": 5,
   "intent": "Run it: which brands moved toward Barbie's audience after the July release?",
   "sql": "WITH likes AS (\n  SELECT DISTINCT -(e.user_id + 1) AS src, CAST(i.brand_id AS BIGINT) AS dst,\n         e.event_time >= TIMESTAMP '2023-07-01 00:00:00' AS after_release\n  FROM merrec_events e JOIN merrec_items i ON i.item_id = e.item_id\n  WHERE e.event_type = 'item_like' AND i.brand_id <> 0\n    AND e.event_time >= TIMESTAMP '2023-05-01 00:00:00'\n    AND e.event_time < TIMESTAMP '2023-09-01 00:00:00'\n), lift_before AS (\n  SELECT p.vertex, p.value / r.value AS lift\n  FROM cugraph_personalized_pagerank(\n    edges => (SELECT src, dst FROM likes WHERE NOT after_release),\n    personalization => (SELECT 2595 AS vertex, 1.0 AS value),\n    directed => false) p\n  JOIN cugraph_pagerank(\n    edges => (SELECT src, dst FROM likes WHERE NOT after_release), directed => false) r\n    ON r.vertex = p.vertex\n), lift_after AS (\n  SELECT p.vertex, p.value / r.value AS lift\n  FROM cugraph_personalized_pagerank(\n    edges => (SELECT src, dst FROM likes WHERE after_release),\n    personalization => (SELECT 2595 AS vertex, 1.0 AS value),\n    directed => false) p\n  JOIN cugraph_pagerank(\n    edges => (SELECT src, dst FROM likes WHERE after_release), directed => false) r\n    ON r.vertex = p.vertex\n), fans AS (\n  SELECT dst AS brand_id,\n         SUM(CASE WHEN after_release THEN 0 ELSE 1 END) AS fans_before,\n         SUM(CASE WHEN after_release THEN 1 ELSE 0 END) AS fans_after\n  FROM likes GROUP BY dst\n), brands AS (\n  SELECT CAST(brand_id AS BIGINT) AS brand_id, MIN(brand_name) AS brand_name\n  FROM merrec_items WHERE brand_id <> 0 GROUP BY brand_id\n)\nSELECT b.brand_name, f.fans_before, f.fans_after,\n       lb.lift AS lift_before, la.lift AS lift_after, la.lift / lb.lift AS lift_change\nFROM lift_after la\nJOIN lift_before lb ON lb.vertex = la.vertex\nJOIN fans f ON f.brand_id = la.vertex\nJOIN brands b ON b.brand_id = la.vertex\nWHERE la.vertex > 0 AND la.vertex <> 2595\n  AND f.fans_before >= 1000 AND f.fans_after >= 1000\nORDER BY lift_change DESC, b.brand_name\nLIMIT 25;",
   "status": "ok",
   "elapsed_s": 3.3178140989039093,
   "source_cache_resident_before": {
    "items.parquet": 1.0,
    "events.parquet": 1.0
   },
   "query_id": "4c00f57a-0cc8-44a3-b57a-0312dd4fbfa7",
   "execution": {
    "post_native_execution_path": "native",
    "native_plan_fragment_count": "11",
    "host_datafusion_boundary_count": "0",
    "peak_gib": 29.7
   },
   "rows": [
    {
     "brand_name": "NYX",
     "fans_before": 2781,
     "fans_after": 4253,
     "lift_before": 0.9702536288473614,
     "lift_after": 2.069575818786982,
     "lift_change": 2.1330255896549337
    },
    {
     "brand_name": "Amc",
     "fans_before": 2654,
     "fans_after": 2815,
     "lift_before": 0.974835772628121,
     "lift_after": 1.820914719301097,
     "lift_change": 1.8679194695450891
    },
    {
     "brand_name": "Primark",
     "fans_before": 1966,
     "fans_after": 2987,
     "lift_before": 1.100701129377499,
     "lift_after": 2.0405481221730764,
     "lift_change": 1.853862113621258
    },
    {
     "brand_name": "ALDO",
     "fans_before": 4571,
     "fans_after": 6379,
     "lift_before": 0.8514795429073221,
     "lift_after": 1.502451737505666,
     "lift_change": 1.7645188895268598
    },
    {
     "brand_name": "Taylor Swift",
     "fans_before": 15577,
     "fans_after": 18514,
     "lift_before": 0.6494634413140877,
     "lift_after": 0.9581264043999292,
     "lift_change": 1.4752584109450568
    },
    {
     "brand_name": "Stoney Clover Lane",
     "fans_before": 5156,
     "fans_after": 5420,
     "lift_before": 1.0601656087864544,
     "lift_after": 1.5021175630610628,
     "lift_change": 1.416870676252647
    },
    {
     "brand_name": "Stanley",
     "fans_before": 16209,
     "fans_after": 16642,
     "lift_before": 0.49297024461696226,
     "lift_after": 0.6880479858617968,
     "lift_change": 1.3957190994284248
    },
    {
     "brand_name": "Dunkin'",
     "fans_before": 1580,
     "fans_after": 1459,
     "lift_before": 0.7278208437624923,
     "lift_after": 1.010969176346272,
     "lift_change": 1.3890357565469487
    },
    {
     "brand_name": "Henri Bendel",
     "fans_before": 1133,
     "fans_after": 1358,
     "lift_before": 0.6493267043168143,
     "lift_after": 0.8548874439419886,
     "lift_change": 1.3165752128452102
    },
    {
     "brand_name": "Dutch Bros",
     "fans_before": 1035,
     "fans_after": 1086,
     "lift_before": 0.5347161436898036,
     "lift_after": 0.7002860869880118,
     "lift_change": 1.30964081644458
    },
    {
     "brand_name": "Fresh",
     "fans_before": 1136,
     "fans_after": 1325,
     "lift_before": 1.3315948349120303,
     "lift_after": 1.739209278059506,
     "lift_change": 1.306109961123726
    },
    {
     "brand_name": "Starbucks",
     "fans_before": 26096,
     "fans_after": 29130,
     "lift_before": 0.7560988611686769,
     "lift_after": 0.9780395291461631,
     "lift_change": 1.2935339270772608
    },
    {
     "brand_name": "BOGG BAG",
     "fans_before": 4578,
     "fans_after": 3496,
     "lift_before": 0.521001595171577,
     "lift_after": 0.672753935740426,
     "lift_change": 1.2912703952832885
    },
    {
     "brand_name": "Farm Rio",
     "fans_before": 2782,
     "fans_after": 3044,
     "lift_before": 0.5037218722608601,
     "lift_after": 0.643431593797627,
     "lift_change": 1.2773548841738922
    },
    {
     "brand_name": "Alice + Olivia",
     "fans_before": 1279,
     "fans_after": 1511,
     "lift_before": 0.6314239613818571,
     "lift_after": 0.8051047705091445,
     "lift_change": 1.2750621131754185
    },
    {
     "brand_name": "HAUS LABORATORIES",
     "fans_before": 1111,
     "fans_after": 1361,
     "lift_before": 0.7191215607652373,
     "lift_after": 0.9158310521539136,
     "lift_change": 1.2735413622967338
    },
    {
     "brand_name": "Interscope Records",
     "fans_before": 1630,
     "fans_after": 2218,
     "lift_before": 0.9198744687519776,
     "lift_after": 1.169039965503048,
     "lift_change": 1.27086902095361
    },
    {
     "brand_name": "MacKenzie-Childs",
     "fans_before": 1270,
     "fans_after": 1758,
     "lift_before": 0.5764184248206329,
     "lift_after": 0.7286124379092185,
     "lift_change": 1.2640339144883244
    },
    {
     "brand_name": "ZARA",
     "fans_before": 38166,
     "fans_after": 48545,
     "lift_before": 0.6506154623226323,
     "lift_after": 0.820134820739725,
     "lift_change": 1.2605523050619263
    },
    {
     "brand_name": "Bombshell Sportswear",
     "fans_before": 1113,
     "fans_after": 1285,
     "lift_before": 0.5058789068498597,
     "lift_after": 0.6375117200629787,
     "lift_change": 1.2602061707470766
    },
    {
     "brand_name": "OPI",
     "fans_before": 2406,
     "fans_after": 3063,
     "lift_before": 0.7159357090239905,
     "lift_after": 0.8989143480968065,
     "lift_change": 1.2555797074604145
    },
    {
     "brand_name": "Dagne Dover",
     "fans_before": 1823,
     "fans_after": 2390,
     "lift_before": 0.4315092577405609,
     "lift_after": 0.5392955031503286,
     "lift_change": 1.2497889523254972
    },
    {
     "brand_name": "Rothy's",
     "fans_before": 4272,
     "fans_after": 4756,
     "lift_before": 0.44114877255991186,
     "lift_after": 0.5506279056182595,
     "lift_change": 1.2481682821490325
    },
    {
     "brand_name": "Brahmin",
     "fans_before": 4044,
     "fans_after": 4290,
     "lift_before": 0.4785214128868047,
     "lift_after": 0.5964184233767231,
     "lift_change": 1.2463777112473904
    },
    {
     "brand_name": "Golden Goose",
     "fans_before": 2855,
     "fans_after": 3436,
     "lift_before": 0.3848386153784122,
     "lift_after": 0.4752099059134255,
     "lift_change": 1.234829060608045
    }
   ]
  }
 ],
 "probes": [
  {
   "label": "personalization columns named after the source table",
   "sql": "SELECT vertex, value\nFROM cugraph_personalized_pagerank(\n  edges => (SELECT DISTINCT -(e.user_id + 1) AS src, CAST(i.brand_id AS BIGINT) AS dst\n            FROM merrec_events e JOIN merrec_items i ON i.item_id = e.item_id\n            WHERE e.event_type = 'item_like' AND i.brand_id <> 0\n              AND e.event_time >= TIMESTAMP '2023-07-01 00:00:00' AND e.event_time < TIMESTAMP '2023-09-01 00:00:00'),\n  personalization => (SELECT 2595 AS brand_id, 1.0 AS weight),\n  directed => false)\nORDER BY value DESC LIMIT 5",
   "status": "error",
   "elapsed_s": 0.0024795071221888065,
   "error": "Flight returned invalid argument error, with message: cuGraph side-input child is missing canonical column 'vertex'"
  },
  {
   "label": "output column named by guess",
   "sql": "SELECT vertex, score\nFROM cugraph_personalized_pagerank(\n  edges => (SELECT DISTINCT -(e.user_id + 1) AS src, CAST(i.brand_id AS BIGINT) AS dst\n            FROM merrec_events e JOIN merrec_items i ON i.item_id = e.item_id\n            WHERE e.event_type = 'item_like' AND i.brand_id <> 0\n              AND e.event_time >= TIMESTAMP '2023-07-01 00:00:00' AND e.event_time < TIMESTAMP '2023-09-01 00:00:00'),\n  personalization => (SELECT 2595 AS vertex, 1.0 AS value),\n  directed => false)\nORDER BY score DESC LIMIT 5",
   "status": "error",
   "elapsed_s": 0.002592553850263357,
   "error": "Flight returned invalid argument error, with message: No field named score. Valid fields are vertex, value."
  }
 ]
}
