feat(core): refacto graph query for perf improvement

[brandPittCode]

PR Description

What this PR Provides

This PR adds several optimizations that enable a low response time for the graph and get entity endpoint

Refactored Graph UUID Discovery via Recursive CTE

• 100% PostgreSQL CTE Compliant: Changed the query to have exactly one UNION ALL connecting the entire anchor set to the recursive set, eliminating the recursive term ordering conflict.
• Optimal Index Utilization: CROSS JOIN LATERAL forces PostgreSQL to perform direct, index-driven lookups (er.entity_id = eg.id and rte.target_entity_uuid = eg.id) for each node at the current graph frontier.

Execution Phase	Before Optimization	After Optimization	Gain
Recursive CTE Query	19 ms	3 ms	84% faster
Total Request Duration	42 ms	18 ms	57% faster

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Drop Defensive Pre-Validation for Entity Template Existence

Skipped the initial template existence pre-check (SELECT et FROM entity_template...) to query the entity table directly. If the template or entity does not exist, the domain exception is thrown immediately without wasting an initial SQL roundtrip.

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Move to EntitySummary for Graph Root Entity & Eliminate 2 Database Calls

Refactored the root entity lookup to fetch only essential entity metadata using the lightweight EntitySummary domain model. This eliminates 2 redundant SQL roundtrip calls previously used to fetch properties and relations.

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Bypass JPA Entity Mapping with PostgreSQL Native JSONB

Added EntityGraphJsonProjection subqueries to aggregate nested array structures directly inside PostgreSQL memory before network transmission, preventing Cartesian explosion in exactly 1 SQL statement. Jackson parses the JSON directly into the domain model, completely skipping Hibernate entity lifecycle overhead and lazy-loading triggers.

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Optimize Jackson Deserialization in PostgresEntityGraphAdapter

Replaced the instantiation of TypeReference objects inside per-entity loops with pre-compiled ObjectReader static instances created during Spring bean initialization. Reusing thread-safe ObjectReader instances across concurrent requests eliminates Jackson reflection setup overhead during array parsing.

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Replace Java Streams with Direct for Loops in Hot Mapping Code

Refactored hot mapping paths in EntityDtoOutFromEntityNodeMapper (which previously spent 66 ms assembling DTO trees) from functional streams (.stream().map(...).toList()) to standard for loops with pre-sized collections. This eliminates thousands of temporary iterator, stream, and lambda allocations during 1,000+ entity graph traversals, directly protecting Cloud Run containers from garbage collection CPU pauses.

Added a new optional query parameter, includeEntityRootProperties to the GraphService

This optimizes response time by changing defaults around property inclusion: includeProperties is now false by default, while includeEntityRootProperties is true by default. This keeps the root entity informative for common API consumers, but avoids loading/mapping properties across related graph nodes unless explicitly requested. In practice, this significantly reduces query/mapping overhead and payload size for graph traversals, improving average latency and tail percentiles (p90/p95) while preserving backward-friendly behavior at the root level.

Optimization results

Baseline:

Load Test Comparison: Baseline vs. Optimized

Infrastructure: 1 vCPU Cloud 2GB RAM
PostgreSQL instance in Aiven: 1 vCPU 4GB RAM

URL: api/v1/entities/supportgroup/CE-IDP?relations_depth=1

Metric	Before Optimization (baseline-depth1-c1)	After Optimization (opt--depth1-c1)	Gain / Reduction
Request Volume	5,000	5,000	—
Success Rate (200 OK)	100% (5,000/5,000)	100% (5,000/5,000)	Identical
Average (Mean)	223.21 ms	66.06 ms	-70.4%
Median (p50)	197.62 ms	62.35 ms	-68.5%
75th Percentile (p75)	233.87 ms	67.67 ms	-71.1%
90th Percentile (p90)	285.88 ms	77.24 ms	-73.0%
95th Percentile (p95)	400.23 ms	87.28 ms	-78.2%
99th Percentile (p99)	509.61 ms	119.52 ms	-76.5%
Minimum	163.18 ms	51.71 ms	-68.3%
Maximum	788.71 ms	449.96 ms	-42.9%
Standard Deviation (Std Dev)	70.77 ms	14.70 ms	-79.2%

Load Test Comparison (Concurrency = 50, 10 calls)

Metric	Non-Optimized (baseline-product-depth4-c50)	Optimized (opt-product-depth4-c50)	Gain / Reduction
Request Volume	10	10	—
Success Rate	100% (10/10)	100% (10/10)	Identical
Average (Mean)	3,860.21 ms	1,380.58 ms	-64.2%
Median (p50)	4,494.69 ms	1,574.24 ms	-65.0%
75th Percentile (p75)	4,842.10 ms	1,711.51 ms	-64.7%
90th Percentile (p90)	4,962.78 ms	1,774.91 ms	-64.2%
95th Percentile (p95)	4,965.55 ms	1,780.28 ms	-64.2%
99th Percentile (p99)	4,967.76 ms	1,784.59 ms	-64.1%
Minimum	515.77 ms	178.46 ms	-65.4%
Maximum	4,968.31 ms	1,785.66 ms	-64.1%
Standard Deviation (Std Dev)	1,564.85 ms	560.03 ms	-64.2%

Large graph results

On a single 1 vCPU Cloud Run container, processing, parsing, and mapping 1,589 full entities in memory dropped from ~300–600 ms down to just 35 ms total.

Step-by-Step Breakdown of the 993 ms Server Request

Step	Component	Duration	What Is Happening
Auth Check	JitProvisioningFilter	15 ms	Pre-controller service account validation
Root Lookup	PostgresEntityAdapter	5 ms	Index seek for root entity UUID
CTE Discovery	PostgresEntityGraphAdapter	374 ms	PostgreSQL 4-level deep recursive CTE graph traversal
JSONB Fetch	PostgresEntityGraphAdapter	145 ms	PostgreSQL native jsonb_agg query for 1,589 entities
Projection Mapping	PostgresEntityGraphAdapter	33 ms	Jackson ObjectReader parses 1,589 entity payloads in JVM RAM
Template Lookup	EntityDtoOutFromEntityNodeMapper	46 ms	DB Query 4: Uncached schema lookup for entity_template
DTO Mapping	EntityDtoOutFromEntityNodeMapper	2 ms	Pre-sized HashMap & imperative for loop graph assembly
HTTP Serialization	EntityController	373 ms	Spring MVC encoding & writing the 140.48 KiB JSON string to the socket
TOTAL SERVER	EntityController	993 ms	Complete Spring Boot Server Time (< 1.0s)

Fixes

Review

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• The reviewer has tested the feature
• The reviewer has reviewed the implementation of the feature
• The documentation has been updated
• The feature implementation respects the Technical Doc / ADR previously produced
• The Pull Request title has a ! after the type/scope to identify the breaking
  change in the release note and ensure we will release a major version.

How to test

Please refer (copy/paste) the test section from the User Story. This should include

• Run unit tests

Breaking changes (if any)

• N/A

Context of the Breaking Change

For example: we redefined the component types list in the DPAC referential

Result of the Breaking Change

For example: your component of type xxx will migrate to the type yyy

[github-code-quality]

Code Coverage Overview

Languages: Java

Java / code-coverage/jacoco

The overall line coverage in commit 3693dd9 in the feat/improve-graph-p... branch remains at 91%, unchanged from commit fcfb416 in the main branch.

Show a line coverage summary of the most impacted files.

File	main fcfb416	feat/improve-graph-p... 3693dd9	+/-
com/decathlon/i...oOutMapper.java	97%	95%	-2%
com/decathlon/i...raphHelper.java	95%	95%	0%
com/decathlon/i...gProcessor.java	81%	81%	0%
com/decathlon/i...NodeMapper.java	92%	92%	0%
com/decathlon/i...oOutMapper.java	87%	87%	0%
com/decathlon/i...figuration.java	100%	100%	0%
com/decathlon/i...yValidator.java	100%	100%	0%
com/decathlon/i...aphService.java	88%	90%	+2%
com/decathlon/i...aphAdapter.java	73%	89%	+16%
com/decathlon/i...eryOptions.java	0%	100%	+100%

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_{Updated October 13, 2026 12:36 UTC}

[Copilot]

🟡 Changes recommended

The implementation ignores property-loading controls, permits recursive path multiplication, and changes established validation and ordering behavior.

6 open findings

• Restore null and empty-input guard before CTE execution · New
• Restore fail-fast template validation · New
• Honor includeProperties to avoid unnecessary property aggregation · New
• Preserve canonical ordering in JSON projections · New
• Deduplicate recursive frontier with UNION · New
• Add adapter tests for JSON projections and property loading · New

What changed in this PR

Optimizes entity graph retrieval through UUID summaries, recursive SQL traversal, and native JSONB projection mapping.

Changes:

• Reworks graph traversal and entity loading for fewer database round trips.
• Adds UUIDs to entity summaries and uses summaries for root lookup.
• Reduces mapping allocations and removes unused logging.

File	Description
RelationValidationServiceTest.java	Updates summary fixtures with UUIDs.
EntityServiceTest.java	Updates summary construction.
EntityGraphServiceTest.java	Adapts graph tests to summary-based root lookup.
application.yml	Adds whitespace.
application-local.yml	Enables local SQL logging.
JpaEntityRepository.java	Adds UUID projections, optimized CTE, and JSONB query.
PostgresEntityGraphAdapter.java	Maps native JSON projections into domain entities.
EntityGraphJsonProjection.java	Defines the native graph projection.
HmacSha256SecurityValidator.java	Removes unused logging support.
DecodingProcessor.java	Removes unused logging support.
EntityDtoOutMapper.java	Removes unused logging support.
EntityDtoOutFromEntityNodeMapper.java	Removes unused logging support.
EntityGraphFlatDtoOutMapper.java	Uses imperative property mapping.
EntityGraphController.java	Removes redundant whitespace.
SecurityConfiguration.java	Removes unused logging support.
EntityGraphService.java	Uses lightweight summaries for graph roots.
EntitySummary.java	Adds the entity UUID.

🧠 Review effort: Balanced

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[Copilot]

🟡 Changes recommended

Domain validation, CI formatting, and native traversal test coverage issues remain unresolved.

3 open findings

• Reject null traversal mode in options constructor · New
• Add database tests for traversal directions and inbound LATERAL · New
• Format source according to Spotless requirements · New

6 resolved since last review

• Restore null and empty-input guard before CTE execution
• Deduplicate recursive frontier with UNION
• Preserve canonical ordering in JSON projections
• Honor includeProperties to avoid unnecessary property aggregation
• Restore fail-fast template validation
• Add adapter tests for JSON projections and property loading

🧠 Review effort: Balanced

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
83.8% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud