Re: Few comments on commit 857f9c36 (skip full index scans )

Hi!

On Mon, May 28, 2018 at 11:52 AM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
wrote:

> Review comments on commit 857f9c36:
> 1.
> @@ -2049,6 +2055,10 @@ _bt_newroot(Relation rel, Buffer lbuf, Buffer rbuf)
> metapg = BufferGetPage(metabuf);
> metad = BTPageGetMeta(metapg);
>
> + /* upgrade metapage if needed */
> + if (metad->btm_version < BTREE_VERSION)
> + _bt_upgrademetapage(metapg);
> +
>
> The metapage upgrade should be performed under critical section.
>
> 2.
> @@ -191,6 +304,10 @@ _bt_getroot(Relation rel, int access)
> LockBuffer(metabuf, BUFFER_LOCK_UNLOCK);
> LockBuffer(metabuf, BT_WRITE);
>
> + /* upgrade metapage if needed */
> + if (metad->btm_version < BTREE_VERSION)
> + _bt_upgrademetapage(metapg);
> +
>
> Same as above.
>
> In other cases like _bt_insertonpg, the upgrade is done inside the
> critical section. It seems the above cases are missed.
>
> 3.
> + TransactionId btm_oldest_btpo_xact; /* oldest btpo_xact among of
> + * deleted pages */
>
> /among of/among all
>
> Attached patch to fix the above comments.
>

Thank you for catching this!
Your patch looks good for me.

------
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company