Thanks for using Cloudera Community. We hope the response by @balajip was helpful for your ask. Additionally, We wish to share a few details:
- Your Question points to "How To Make Query Faster". Ideally, Impala would use Parallelism for executing a Query in fragments across Executors. As such, the 1st review should be using Impala Query Profile of the SQL to identify the Time taken at each Phase of SQL Execution. Refer  &  for few Links around Impala Query Profile.
- Once the Phase taking the Most Time is identified, Fine-Tune accordingly. Simply increasing the Impala Executors Daemon or using a Dedicated Coordinator may not be helpful, unless the SQL's Slow Fragment(s) are identified.
Kindly review & let us know if you have any further ask in the Post.