Re: Block-level CRC checks - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: Block-level CRC checks
Date
Msg-id 20081030131806.GB3857@alvh.no-ip.org
Whole thread Raw
In response to Re: Block-level CRC checks  (Alvaro Herrera <alvherre@commandprompt.com>)
Responses Re: Block-level CRC checks  (Gregory Stark <stark@enterprisedb.com>)
List pgsql-hackers
Alvaro Herrera wrote:

> The "other hint bits" are:
> 
> - LP_DEAD as used by the various callers of ItemIdMarkDead.
> - PD_PAGE_FULL
> - BTPageOpaque->btpo_flags and btpo_cycleid
> 
> All of them are changed with only SetBufferCommitInfoNeedsSave being
> called afterwards.

I think we could get away with WAL-logging LP_DEAD via ItemIdMarkDead
similar to what is done to SetHintBits in the posted patch, and cope
with the rest by marking the page with the invalid checksum; they are
not so frequent anyway so the reliability loss is low.

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.


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