Re: Online base backup from the hot-standby - Mailing list pgsql-hackers

From Jun Ishiduka
Subject Re: Online base backup from the hot-standby
Date
Msg-id 201110180627.p9I6R8Qj031051@ccmds32.silk.ntts.co.jp
Whole thread Raw
In response to Re: Online base backup from the hot-standby  (Fujii Masao <masao.fujii@gmail.com>)
Responses Re: Online base backup from the hot-standby  (Jun Ishiduka <ishizuka.jun@po.ntts.co.jp>)
List pgsql-hackers
> +         /*
> +          * The backend writes WAL of FPW at checkpoint. However, The backend do
> +          * not need to write WAL of FPW at checkpoint shutdown because it
> +          * performs when startup finishes.
> +          */
> +         XLogReportParameters(REPORT_ON_BACKEND);
> 
> I'm still unclear why that WAL doesn't need to be written at shutdown
> checkpoint.
> Anyway, the first sentence in the above comments is not right. Not a backend but
> a bgwriter writes that WAL at checkpoint.
> 
> The second also seems not to be right. It implies that a shutdown checkpoint is
> performed only at end of startup. But it may be done when smart or fast shutdown
> is requested.


Okay. 
I change to the following messages.

/* * The bgwriter writes WAL of FPW at checkpoint. But does not at shutdown.* Because XLogReportParameters() is always
calledat the end of startup* process, it does not need to be called at shutdown.*/
 


In addition, I change macro name.

REPORT_ON_BACKEND -> REPORT_ON_BGWRITER


Regards.

--------------------------------------------
Jun Ishizuka
NTT Software Corporation
TEL:045-317-7018
E-Mail: ishizuka.jun@po.ntts.co.jp
--------------------------------------------




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