# All files / framework/query QueryOptimizer.ts

0% Statements 0/130
0% Branches 0/73
0% Functions 0/18
0% Lines 0/126

Press n or j to go to the next uncovered block, b, p or k for the previous block.

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66
    67
    68
    69
    70
    71
    72
    73
    74
    75
    76
    77
    78
    79
    80
    81
    82
    83
    84
    85
    86
    87
    88
    89
    90
    91
    92
    93
    94
    95
    96
    97
    98
    99
    100
    101
    102
    103
    104
    105
    106
    107
    108
    109
    110
    111
    112
    113
    114
    115
    116
    117
    118
    119
    120
    121
    122
    123
    124
    125
    126
    127
    128
    129
    130
    131
    132
    133
    134
    135
    136
    137
    138
    139
    140
    141
    142
    143
    144
    145
    146
    147
    148
    149
    150
    151
    152
    153
    154
    155
    156
    157
    158
    159
    160
    161
    162
    163
    164
    165
    166
    167
    168
    169
    170
    171
    172
    173
    174
    175
    176
    177
    178
    179
    180
    181
    182
    183
    184
    185
    186
    187
    188
    189
    190
    191
    192
    193
    194
    195
    196
    197
    198
    199
    200
    201
    202
    203
    204
    205
    206
    207
    208
    209
    210
    211
    212
    213
    214
    215
    216
    217
    218
    219
    220
    221
    222
    223
    224
    225
    226
    227
    228
    229
    230
    231
    232
    233
    234
    235
    236
    237
    238
    239
    240
    241
    242
    243
    244
    245
    246
    247
    248
    249
    250
    251
    252
    253
    254
    255

     import { QueryBuilder } from './QueryBuilder';
    import { QueryCondition } from '../types/queries';
    import { BaseModel } from '../models/BaseModel';

    export interface QueryPlan {
      strategy: 'single_user' | 'multi_user' | 'global_index' | 'all_shards' | 'specific_shards';
      targetDatabases: string[];
      estimatedCost: number;
      indexHints: string[];
      optimizations: string[];
    }

    export class QueryOptimizer {
      static analyzeQuery<T extends BaseModel>(query: QueryBuilder<T>): QueryPlan {
        const model = query.getModel();
        const conditions = query.getConditions();
        const relations = query.getRelations();
        const limit = query.getLimit();

        let strategy: QueryPlan['strategy'] = 'all_shards';
        let targetDatabases: string[] = [];
        let estimatedCost = 100; // Base cost
        let indexHints: string[] = [];
        let optimizations: string[] = [];

        // Analyze based on model scope
        if (model.scope === 'user') {
          const userConditions = conditions.filter(
            (c) => c.field === 'userId' || c.operator === 'userIn',
          );

          if (userConditions.length > 0) {
            const userCondition = userConditions[0];

            if (userCondition.operator === 'userIn') {
              strategy = 'multi_user';
              targetDatabases = userCondition.value.map(
                (userId: string) => `${userId}-${model.modelName.toLowerCase()}`,
              );
              estimatedCost = 20 * userCondition.value.length;
              optimizations.push('Direct user database access');
            } else {
              strategy = 'single_user';
              targetDatabases = [`${userCondition.value}-${model.modelName.toLowerCase()}`];
              estimatedCost = 10;
              optimizations.push('Single user database access');
            }
          } else {
            strategy = 'global_index';
            targetDatabases = [`${model.modelName}GlobalIndex`];
            estimatedCost = 50;
            indexHints.push(`${model.modelName}GlobalIndex`);
            optimizations.push('Global index lookup');
          }
        } else {
          // Global model
          if (model.sharding) {
            const shardKeyCondition = conditions.find((c) => c.field === model.sharding!.key);

            if (shardKeyCondition) {
              if (shardKeyCondition.operator === '=') {
                strategy = 'specific_shards';
                targetDatabases = [`${model.modelName}-shard-specific`];
                estimatedCost = 15;
                optimizations.push('Single shard access');
              } else if (shardKeyCondition.operator === 'in') {
                strategy = 'specific_shards';
                targetDatabases = shardKeyCondition.value.map(
                  (_: any, i: number) => `${model.modelName}-shard-${i}`,
                );
                estimatedCost = 15 * shardKeyCondition.value.length;
                optimizations.push('Multiple specific shards');
              }
            } else {
              strategy = 'all_shards';
              estimatedCost = 30 * (model.sharding.count || 4);
              optimizations.push('All shards scan');
            }
          } else {
            strategy = 'single_user'; // Actually single global database
            targetDatabases = [`global-${model.modelName.toLowerCase()}`];
            estimatedCost = 25;
            optimizations.push('Single global database');
          }
        }

        // Adjust cost based on other factors
        if (limit && limit < 100) {
          estimatedCost *= 0.8;
          optimizations.push(`Limit optimization (${limit})`);
        }

        if (relations.length > 0) {
          estimatedCost *= 1 + relations.length * 0.3;
          optimizations.push(`Relationship loading (${relations.length})`);
        }

        // Suggest indexes based on conditions
        const indexedFields = conditions
          .filter((c) => c.field !== 'userId' && c.field !== '__or__' && c.field !== '__raw__')
          .map((c) => c.field);

        if (indexedFields.length > 0) {
          indexHints.push(...indexedFields.map((field) => `${model.modelName}_${field}_idx`));
        }

        return {
          strategy,
          targetDatabases,
          estimatedCost,
          indexHints,
          optimizations,
        };
      }

      static optimizeConditions(conditions: QueryCondition[]): QueryCondition[] {
        const optimized = [...conditions];

        // Remove redundant conditions
        const seen = new Set();
        const filtered = optimized.filter((condition) => {
          const key = `${condition.field}_${condition.operator}_${JSON.stringify(condition.value)}`;
          if (seen.has(key)) {
            return false;
          }
          seen.add(key);
          return true;
        });

        // Sort conditions by selectivity (most selective first)
        return filtered.sort((a, b) => {
          const selectivityA = this.getConditionSelectivity(a);
          const selectivityB = this.getConditionSelectivity(b);
          return selectivityA - selectivityB;
        });
      }

      private static getConditionSelectivity(condition: QueryCondition): number {
        // Lower numbers = more selective (better to evaluate first)
        switch (condition.operator) {
          case '=':
            return 1;
          case 'in':
            return Array.isArray(condition.value) ? condition.value.length : 10;
          case '>':
          case '<':
          case '>=':
          case '<=':
            return 50;
          case 'like':
          case 'ilike':
            return 75;
          case 'is_not_null':
            return 90;
          default:
            return 100;
        }
      }

      static shouldUseIndex(field: string, operator: string, model: typeof BaseModel): boolean {
        // Check if field has index configuration
        const fieldConfig = model.fields?.get(field);
        if (fieldConfig?.index) {
          return true;
        }

        // Certain operators benefit from indexes
        const indexBeneficialOps = ['=', 'in', '>', '<', '>=', '<=', 'between'];
        return indexBeneficialOps.includes(operator);
      }

      static estimateResultSize(query: QueryBuilder<any>): number {
        const conditions = query.getConditions();
        const limit = query.getLimit();

        // If there's a limit, that's our upper bound
        if (limit) {
          return limit;
        }

        // Estimate based on conditions
        let estimate = 1000; // Base estimate

        for (const condition of conditions) {
          switch (condition.operator) {
            case '=':
              estimate *= 0.1; // Very selective
              break;
            case 'in':
              estimate *= Array.isArray(condition.value) ? condition.value.length * 0.1 : 0.1;
              break;
            case '>':
            case '<':
            case '>=':
            case '<=':
              estimate *= 0.5; // Moderately selective
              break;
            case 'like':
              estimate *= 0.3; // Somewhat selective
              break;
            default:
              estimate *= 0.8;
          }
        }

        return Math.max(1, Math.round(estimate));
      }

      static suggestOptimizations<T extends BaseModel>(query: QueryBuilder<T>): string[] {
        const suggestions: string[] = [];
        const conditions = query.getConditions();
        const model = query.getModel();
        const limit = query.getLimit();

        // Check for missing userId in user-scoped queries
        if (model.scope === 'user') {
          const hasUserFilter = conditions.some((c) => c.field === 'userId' || c.operator === 'userIn');
          if (!hasUserFilter) {
            suggestions.push('Add userId filter to avoid expensive global index query');
          }
        }

        // Check for missing limit on potentially large result sets
        if (!limit) {
          const estimatedSize = this.estimateResultSize(query);
          if (estimatedSize > 100) {
            suggestions.push('Add limit() to prevent large result sets');
          }
        }

        // Check for unindexed field queries
        for (const condition of conditions) {
          if (!this.shouldUseIndex(condition.field, condition.operator, model)) {
            suggestions.push(`Consider adding index for field: ${condition.field}`);
          }
        }

        // Check for expensive operations
        const expensiveOps = conditions.filter((c) =>
          ['like', 'ilike', 'array_contains'].includes(c.operator),
        );
        if (expensiveOps.length > 0) {
          suggestions.push('Consider using more selective filters before expensive operations');
        }

        // Check for OR conditions
        const orConditions = conditions.filter((c) => c.operator === 'or');
        if (orConditions.length > 0) {
          suggestions.push('OR conditions can be expensive, consider restructuring query');
        }

        return suggestions;
      }
    }