Hello everyone!
We have some issue with truncated pg_control file on Windows after power 
failure.My questions is : 1) Is pg_control protected from say , power crash or 
partial write? 2) How PG update pg_control? By writing in it or writing in some 
temp file and after that rename it to pg_control to be atomic?3) Can PG have  
multiple pg_control copy to be more fault tolerant?
PS During some experiments we found that at present time there is no any method 
to do crash recovery with "restored" version of pg_control (based on some 
manipulations with pg_resetxlog ). Only by using pg_resetxlog and setting it 
parameters to values taken from wal file (pg_xlogdump)we can at least start PG 
and saw that PG state is at the moment of last check point. But we have no real 
confidence that PG is in consistent state(also docs on pg_resetxlogs told us 
about it too)

Alex IgnatovPostgres Professional: http://www.postgrespro.comRussian Postgres 

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