GlideSystem (gs) - the utility belt

GlideSystem is the utility API available in all server-side scripts via the gs global object. It provides methods that are used constantly across the platform.

• Logging - gs.info(), gs.warn(), gs.error(), gs.debug() - the correct way to log information from server-side scripts. Logs appear in the System Log and are filterable by level. gs.debug() messages only appear when debug logging is enabled - use it for development-time information that should not appear in production logs.
• User context - gs.getUserID(), gs.getUserName(), gs.hasRole() - methods that return information about the current session user. Used in access control logic, personalisation, and audit trail creation.
• System properties - gs.getProperty() - reads values from System Properties (sys_properties) - the platform's configuration store. Hard-coding values in scripts is bad practice. Storing configurable values in System Properties and reading them with gs.getProperty() makes scripts maintainable without code changes.
• Date and time - gs.now(), gs.nowDateTime(), gs.daysAgo() - utility methods for date calculations. ServiceNow's date/time handling has specific requirements - using gs methods ensures timezone and format consistency.

GlideAggregate - counting and summing at scale

GlideAggregate performs aggregate database operations - COUNT, SUM, AVG, MIN, MAX - without loading individual records into memory. It is the correct tool when you need statistics about a set of records rather than the records themselves.

The performance difference between counting records in a GlideRecord loop versus using GlideAggregate.addAggregate('COUNT') can be dramatic on large tables. A GlideRecord count loop on 10,000 records loads all 10,000 into memory. GlideAggregate returns a single count from the database without loading any records. In reporting scripts, Scheduled Jobs, and any context where you need aggregate data, GlideAggregate is the correct choice.