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[question] difference between vm_extend and fsm_extend - Mailing list pgsql-hackers

From Junwang Zhao
Subject [question] difference between vm_extend and fsm_extend
Date
Msg-id CAEG8a3K_zajxhWMpJO=f1Z70kBjwe3RiMb9_Jyv4=8M9sSJEow@mail.gmail.com
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Hey hacks,

I'm looking the code of free space map and visibility map, both the module
call  `ExtendBufferedRelTo` to extend its file when necessary, what confused
me is that `vm_extend` has an extra step that send a shared message to force
other backends to close other smgr references.

My question is why does `fsm_extend` not need the invalidation step?

-- 
Regards
Junwang Zhao

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