SSRS - Error

"An error occurred within the report server database. This may be due to a connection failure, timeout or low disk condition within the database. (rsReportServerDatabaseError) Get Online Help
Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding"

We get this issue from the users asking, we are unable to open the report history with attaching some links.

i just update the stats and rebuild the indexes on the table and that works. But, what might be the root cause of this to get the Timeout error.

Thank you!!

if the problem is fixed by rebuilding the indexes, then the problem is probably out-of-date stats leading to a poor execution plan. if the cardinality estimates are way off, you might get loops instead of a hash join, e.g.

As this is a temporary solution to get these report history to work. But, we need to have permanent fix for this issue.
Any thoughts on fixes/maintenance that can be performed so we don't continually get this error.

reorg indexes after 5% fragmentation and rebuild at 30%. Rebuild recomputes the stats as well