after updating change workflow in database, the changes which in front end takes 30 min approx what could be the reason ?
Which product are you referring to ? Whether it's SDM or Catalog, you should not update records directly in the Database, that's not the correct way to modify records.
CA Service Desk 14.4.04
Why are you updating records directly via the database?
What table(s) are you updating?
This is not recommended.
We are workflow table , i think my approach is worn i should rather use rest API.
Have you tried a cache refresh on the impacted tables?
For example, pdm_cache_refresh -t Workflow_Task
Retrieving data ...