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ZavaHospital – SQL Server 2025 + NVIDIA NIM on AKS

Architecture

• SQL Server 2025 on localhost, Windows auth, database zavahospital
• NVIDIA NIM embeddings: nvidia/nv-embedqa-e5-v5-query (1024 dims, T4 GPU on AKS)
• NVIDIA NIM chat: meta/llama-3.2-3b-instruct (T4 GPU on AKS)
• AKS cluster: aks-nvidianim in rg-nvidianim-westus2, 2x NC4as_T4_v3 GPU nodes
• TLS: Self-signed cert (CN=nim-aks.local) via AKS Web App Routing (managed NGINX ingress)
• Hostname: nim-aks.local → <aks-ingress-ip> via hosts file
• Content-Type fix: NGINX annotation proxy_set_header Content-Type "application/json"

Flow

SQL Server 2025 → HTTPS → AKS Ingress (nim-aks.local) → NIM pods

• Embeddings: AI_GENERATE_EMBEDDINGS(@prompt USE MODEL NIMEmbeddingModel) → 1024-dim vector
• Chat: sp_invoke_external_rest_endpoint → https://nim-aks.local/v1/chat/completions
• Vector search: VECTOR_SEARCH() with DiskANN index (cosine metric)

Critical Facts

• PREVIEW_FEATURES = ON is REQUIRED — 01_schema.sql sets ALTER DATABASE SCOPED CONFIGURATION SET PREVIEW_FEATURES = ON; which is mandatory for CREATE VECTOR INDEX and VECTOR_SEARCH() in SQL Server 2025
• Embedding model name MUST use -query suffix: nvidia/nv-embedqa-e5-v5-query. The -query suffix bakes in the input_type=query parameter server-side — AI_GENERATE_EMBEDDINGS cannot send input_type.
• Vector dimensions are 1024 (not 1536)
• sp_invoke_external_rest_endpoint max timeout is 120 seconds
• NIM rejects application/json;charset=utf-8 — the NGINX annotation strips the charset suffix
• Chat model (llama-3.2-3b) is small — system prompt MUST include grounding facts for quality answers
• 01_schema.sql runs against master (creates the database). All other scripts run against zavahospital.
• Script 08 and 13 call NIM to generate embeddings — they take longer than other scripts
• Post-filter compensation: VECTOR_SEARCH() applies JOINs/WHERE after the ANN scan, so procs over-fetch 3x

Database Design

• Schemas: ref (reference), core (patients/encounters), clinical (vitals/notes/orders/alerts), sec (RLS)
• Ledger: clinical.DoctorNotes uses LEDGER = ON (APPEND_ONLY = ON) for audit immutability
• RLS: Row-Level Security predicates scope data by building/ward via SESSION_CONTEXT
• ADR: ACCELERATED_DATABASE_RECOVERY = ON
• Optimized Locking: OPTIMIZED_LOCKING = ON
• Data compression: clinical.VitalsSnapshots uses DATA_COMPRESSION = ROW

Stored Procedures

Embedding Tables

Script Execution Order

# Against master (creates database):
sqlcmd -S localhost -d master -E -i 01_schema.sql

# Against zavahospital (all remaining):
sqlcmd -S localhost -d zavahospital -E -i 02_seeding.sql
sqlcmd -S localhost -d zavahospital -E -i 03_procs.sql
sqlcmd -S localhost -d zavahospital -E -i 05_dbcreds.sql -v MasterKeyPassword="<your-strong-password>"
sqlcmd -S localhost -d zavahospital -E -i 06_ai_model.sql
sqlcmd -S localhost -d zavahospital -E -i 07_embedding_table.sql
sqlcmd -S localhost -d zavahospital -E -i 08_genembeddings.sql      # calls NIM
sqlcmd -S localhost -d zavahospital -E -i 09_create_vector_index.sql
sqlcmd -S localhost -d zavahospital -E -i 10_find_similar_cases.sql
sqlcmd -S localhost -d zavahospital -E -i 11_clinical_recommendation.sql
sqlcmd -S localhost -d zavahospital -E -i 13_embeddingtable.sql     # calls NIM
sqlcmd -S localhost -d zavahospital -E -i 14_create_notes_vector_index.sql
sqlcmd -S localhost -d zavahospital -E -i 15_search_doctor_notes.sql

Demo Scripts (run after deployment)

sqlcmd -S localhost -d zavahospital -E -i 04_call_procs.sql
sqlcmd -S localhost -d zavahospital -E -i 12_call_recommendation.sql
sqlcmd -S localhost -d zavahospital -E -i 12_vector_search_exmple.sql
sqlcmd -S localhost -d zavahospital -E -i 16_call_search_doctor_notes.sql

Prerequisites (before running scripts)

1. NIM on AKS deployed and pods running (see nvidianim/SKILL.md)
2. Hosts file: <aks-ingress-ip> nim-aks.local (get the IP from kubectl get ingress -n nim)
3. NIM TLS cert imported into Local Machine Trusted Root CAs
4. SQL Server restarted after cert import
5. sp_invoke_external_rest_endpoint enabled (sp_configure)
6. Verify NIM endpoints respond: .\test-embedding.ps1, .\test-chat.ps1 in nvidianim/

Troubleshooting

• AI_GENERATE_EMBEDDINGS TLS error → import nvidianim\k8s\tls.cer to Trusted Root CAs, restart SQL
• Vector search returns fewer rows than expected → increase @SearchTopN (procs already over-fetch 3x)
• nim-aks.local unreachable → check hosts file, AKS ingress IP, pods running
• EXTERNAL MODEL fails → use API_FORMAT = 'OpenAI', URL must end in /v1/embeddings
• NIM pod OOM → use llama-3.2-3b (not 8B) for chat on T4
• Chat hallucinations → add grounding facts to system prompt (3B model needs explicit context)
• 02_seeding.sql "already seeded" → script has guard clause; drop+recreate via 01_schema.sql first
• Script 08/13 slow → these call NIM for each row; normal for initial population

Demo Narrative

Edge AI pattern: hospital runs SQL Server 2025 + NIM on Azure Local in their data center. Patient data never leaves the building — zero cloud API calls. Same code, same containers, same T-SQL works in cloud AKS or on-premises Azure Local.

Source: microsoft/bobsql — distributed by TomeVault.