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| 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;
}
}
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