searching issues via REST results in a high number of database queries

Problem

A search via REST api call results in a high number of database queries, which could result in database performance issues.

Testing:

I ran a local test:

• Enabled SQL Logging in JIRA
• Ran search via issue navigator (HTTP)

  project = test
  

• confirm SQL logging
• Ran search via REST api

  curl -D- -u admin:admin -X GET -H "Content-Type: application/json" http://localhost:8079/rest/api/2/search?jql=project=test > restsearch-output
  

Results:

• both HTTP and REST searches returned 50 issues (there are a total 1201, but only 50 are shown at a time)
• the 50 issues are all the same issue keys in both searchs
• HTTP - 45 SQL queries
  • including checks/updates to userhistoryitem table, 12 queries
• REST - 413 SQL queries
  • including auth for the user, 20 queries
  • did not seem to check/update userhistoryitem

Edit:

• Just ran same test with com.atlassian.jira.issue.search.providers set to DEBUG
  • HTTP - 5 lines of DEBUG logging
  • REST - 77 lines of DEBUG logging
    • There seems to be extra queries relating to parenttasks. I ran a quick check and there are 10 sub-tasks in the search results.
• see attached file