Postgresql not able to start I am facing below error during postgresql db start.
FATAL: the database system is starting up
FATAL: failed to re-find parent key in index &quot;16619&quot; for split pages 915114/915115

What is the solution of this error?
You are facing data corruption, and it seems that your database had crashed before and now the recovery process is failing.
If you cannot restore from a backup, you will have to find a professional who can salvage as much from the wreck as possible. A Q&amp;A forum will not be able to guide you through this.
Apart from that, you should figure out what may have caused the data corruption, so that you can avoid it in the future. Often the cause is hardware problems.