Re: pg_standby -l might destory the archived file

Simon Riggs wrote:
> On Mon, 2009-06-01 at 14:47 +0900, Fujii Masao wrote:
> 
>> pg_standby can use ln command to restore an archived file,
>> which might destroy the archived file as follows.
>>
>> 1) pg_standby creates the symlink to the archived file '102'
>> 2) '102' is applied
>> 3) the next file '103' doesn't exist and the trigger file is created
>> 4) '102' is re-fetched
>> 5) at the end of recovery, the symlink to '102' is rename to '202',
>>     but it still points '102'
>> 6) after recovery, '202' is recycled (rename to '208', which still
>>     points '102')
>> 7) '208' is written new xlog records over
>>     --> the archived file '102' comes down!
>>
>> One simple solution to fix this problem...
> 
> err...I don't see *any* problem at all, since pg_standby does not do
> step (1) in the way you say and therefore never does step (5). Any links
> created are explicitly deleted in all cases at the end of recovery.

I don't know how you came to that conclusion, but Fujii-sans description 
seems accurate to me, and I can reproduce the behavior on my laptop.

--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com