To create a flamegraph for Postgres, you follow these steps:

1. Install tools to collect data for analysis using eBPF or perf.
   
2. Install packages with debug symbols for Postgres.
   
3. Clone the FlameGraph repository.
   
4. Get the process ID of the Postgres backend to be analyzed.
   
5. Collect data for analysis with the chosen tool.
   
6. Generate a flamegraph using the flamegraph.pl script.
   

For complete instructions, including example commands and details for each step, check out this comprehensive howto on creating Postgres FlameGraphs. Note that the guide is authored by Nikolay Samokhvalov from Postgres.ai. Please ensure all recommendations are tested before applying them to production environments.