Improved GIS map performance 10x on PostgreSQL

Situation. The organization’s geographical map application, which supported real‑time spatial queries for many users, was experiencing severe performance bottlenecks. Latency in rendering map layers and querying location‑based data impacted both user experience and backend service reliability. The system was backed by a legacy Microsoft SQL Server (MSSQL) database that lacked native geospatial indexing.

Task. Improve the performance, scalability, and security of the map application, with a specific goal of reducing query latency and increasing throughput for spatial operations.

Action. Led a strategic migration of the database from MSSQL to PostgreSQL with the PostGIS extension to enable native geospatial support.

• Designed a new schema optimized for spatial data, introducing GiST and SP‑GiST indexes on geometry and geography columns for faster querying.
• Defined strict foreign key and check constraints to ensure relational integrity and enforce data validation rules on spatial coordinates.
• Migrated over 50 million spatial records using ETL pipelines with data transformation steps to conform to new SRID standards (EPSG:4326).
• Tuned PostgreSQL configuration parameters (e.g., work_mem, effective_cache_size) for optimal I/O performance under concurrent access.
• Implemented role‑based access controls (RBAC) and row‑level security to enforce data protection policies across multiple user groups.

Result. Achieved a 10x improvement in spatial query performance, reducing average response time from 2.5 seconds to under 250 milliseconds. Backend CPU load dropped by 65%, and system availability improved during peak usage. Security posture was also strengthened with granular access policies and data validation constraints, reducing potential for spatial data corruption.