Re: Write Ahead Logging for Hash Indexes

On Mon, Sep 12, 2016 at 10:24 PM, Jesper Pedersen
<jesper(dot)pedersen(at)redhat(dot)com> wrote:
>
> Some initial feedback.
>

Thanks for looking into patch.

> README:
> +in_complete split flag. The reader algorithm works correctly, as it will
> scan
>
> What flag ?
>

in-complete-split flag which indicates that split has to be finished
for that particular bucket. The value of these flags are
LH_BUCKET_NEW_PAGE_SPLIT and LH_BUCKET_OLD_PAGE_SPLIT for new and old
bucket respectively. It is set in hasho_flag in special area of page.
I have slightly expanded the definition in README, but not sure if it
is good idea to mention flags defined in hash.h. Let me know, if still
it is unclear or you want some thing additional to be added in README.

> hashxlog.c:
>
> hash_xlog_move_page_contents
> hash_xlog_squeeze_page
>
> Both have "bukcetbuf" (-> "bucketbuf"), and
>
> + if (BufferIsValid(bukcetbuf));
>
> ->
>
> + if (BufferIsValid(bucketbuf))
>
> and indent following line:
>
> LockBufferForCleanup(bukcetbuf);
>
> hash_xlog_delete
>
> has the "if" issue too.
>

Fixed all the above cosmetic issues.

> hash.h:
>
> Move the XLog related content to hash_xlog.h
>

Moved and renamed hashxlog.c to hash_xlog.c to match the name with
corresponding .h file.

Note - This patch is to be applied on top of concurrent hash index v6
version [1]. Jeff, use this version of patch for further review and
test.

[1] - https://www.postgresql.org/message-id/CAA4eK1%2BERbP%2B7mdKkAhJZWQ_dTdkocbpt7LSWFwCQvUHBXzkmA%40mail.gmail.com

--
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com