| From: | Alvaro Herrera <alvherre(at)2ndquadrant(dot)com> |
|---|---|
| To: | Thunder <thunder1(at)126(dot)com> |
| Cc: | pgsql-hackers(at)lists(dot)postgresql(dot)org |
| Subject: | Re: Optimize crash recovery |
| Date: | 2020-03-13 15:41:03 |
| Message-ID: | 20200313154103.GA15832@alvherre.pgsql |
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| Thread: | |
| Lists: | pgsql-hackers |
On 2020-Mar-13, Thunder wrote:
> Hello hackers：
>
>
> During crash recovery, we compare most of the lsn of xlog record with page lsn to determine if the record has already been replayed.
> The exceptions are full-page and init-page xlog records.
> It's restored if the xlog record includes a full-page image of the page.
> And it initializes the page if the xlog record include init page information.
>
>
> When we enable checksum for the page and verify page success, can we
> compare the page lsn with the lsn of full-page xlog record or init
> page xlog record to detemine it has already been replayed?
In order to verify that the checksum passes, you have to read the page
first. So what are you optimizing?
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
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