howto show query process path? (indexes related)

[Patrizio Bassi]

Hi,

for a database project i need to know how indexes impact on query usage.

the explain command gives me only infos if index is used or not...and
some other infos.

i need to know the file access plan.

i mean:
access the index -> find the value -> access the file page

something like a "strace" command.

Is that possibile? i'm on 5.0.18

Thanks