Is there any difference between starting the compilation by execute_flow -compile and by running its individual parts e.g. --analysis_and_elaboration etc. Do they both do the same exact thing? What about PRE_FLOW_SCRIPT_FILE, and other such settings.
The execute_flow command allows you to run some or all the executables in commonly-used combinations.
execute_flow -compile --> Perform a full compilation of the design
execute_flow --analysis_and_elaboration --> Only run analysis and elaboration of the design
Regarding the PRE_FLOW_SCRIPT_FILE, you can refer to the document Automating Script Execution.
Let me know if it helps.