Query runs 1 operator; returns 600 rows in 0.42 ms. No warnings.

Total time
419 µs
Rows returned
600
Rows examined
600
Operators
1

SQL

select testdb.users.id AS id,testdb.users.email AS email
from testdb.users
where (testdb.users.country = 'US')

Execution plan (diagram)

Click a plan operator to inspect details.

MySQL Query Plan Execution plan (left → right) · Total: 419.5 µs · Yellow → Purple = faster → slower · Red SLOWEST badge = fix first Fast Slow SLOWEST = contention point Search Click a node to pin details · +/− to zoom · Drag to pan · Dbl-click to reset · Ctrl+F to search Index lookup on users using idx_country (country='US'), with index con… · Total: 419.5 µs · Cost: 70.50 · Rows: 600 · Loops: 1 · Table: users · Index: idx_country · Est.rows: 600 · Covering: no 419.5 µs Non-Unique Key Lookup users idx_country 600 rows SLOWEST 600 rows Total: 419.5 µs | Cost: 70.50 query_block #1 419.5 µs + − ↺

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Raw sidecar (JSON)

 
{
  "$schema": "https://myflames.dev/schemas/sidecar-v1.json",
  "schema_version": "1.3",
  "generated_at": "2026-04-25T12:51:24Z",
  "myflames_version": "1.5.0",
  "source": {
    "type": "file"
  },
  "plan_summary": {
    "total_time_ms": 0.419,
    "rows_sent": 600,
    "rows_examined_estimate": 600,
    "operator_count": 1,
    "max_depth": 1
  },
  "optimizer_switches": [
    {
      "name": "index_condition_pushdown",
      "value": "on",
      "explanation": "Parts of the WHERE clause are evaluated inside the storage engine using index columns before fetching the full row — reduces rows handed to the server layer.",
      "node_labels": [
        "Index lookup [users.idx_country]"
      ]
    }
  ],
  "warnings": [],
  "suggestions": [],
  "executive_summary": "Query runs 1 operator; returns 600 rows in 0.42 ms. No warnings.",
  "plan_tree": {
    "node_id": "n:72251d1a01c9",
    "short_label": "Index lookup [users.idx_country]",
    "folded_label": "INDEX LOOKUP [users.idx_country] starts=1 rows=600",
    "children": []
  },
  "query": {
    "raw": "/* select#1 */ select `testdb`.`users`.`id` AS `id`,`testdb`.`users`.`email` AS `email` from `testdb`.`users` where (`testdb`.`users`.`country` = 'US')",
    "beautified": "select testdb.users.id AS id,testdb.users.email AS email\nfrom testdb.users\nwhere (testdb.users.country = 'US')"
  },
  "teach_hooks": [
    {
      "lesson": "non_unique_lookup",
      "match": {
        "folded_label": "INDEX LOOKUP [users.idx_country] starts=1 rows=600",
        "short_label": "Index lookup [users.idx_country]"
      },
      "controls": {
        "rows": 600,
        "selectivity": 40.0,
        "covering": false
      },
      "note": "Index lookup on users using idx_country (country='US'), with index condition: (users.country = 'US') (users)",
      "query_sql": "/* select#1 */ select `testdb`.`users`.`id` AS `id`,`testdb`.`users`.`email` AS `email` from `testdb`.`users` where (`testdb`.`users`.`country` = 'US')"
    }
  ],
  "operator_complexities": [
    {
      "node_id": "n:72251d1a01c9",
      "folded_label": "INDEX LOOKUP [users.idx_country] starts=1 rows=600",
      "short_label": "Index lookup [users.idx_country]",
      "complexity": {
        "big_o": "O(log n + k)",
        "short": "log n + k",
        "severity": "good",
        "rationale": "Index lookup (ref): one B+tree descent then a sequential walk over k matching index entries. k = matching rows for the indexed predicate.",
        "confidence": "exact",
        "learn_more": "index_lookup"
      }
    }
  ]
}

Teach: Operator deep dive