Re: Deadlock possibility in _bt_check_unique?

Oh! yeah, i got it. Thanks....

On Wed, Mar 24, 2010 at 12:26 AM, Gokulakannan Somasundaram <
gokul007(at)gmail(dot)com> wrote:

>
> > T2 : session 1 releases the lock on p1 (its waiting to acquire a ex lock
>> on
>> > p2)
>>
>> That's not what we do. See _bt_findinsertloc.
>>
>> regards, tom lane
>>
>
> I am really confused. Please keep the cool and explain me, if i am
> wrong. I could see this code in _bt_findinsertloc. There is a
> _bt_relandgetbuf, which releases lock on p1 and tries to acquire a lock on
> p2. I wrote ex lock in the place of BT_WRITE.
> *
> *
>
> *00589 for (;;)
> 00590 {
> 00591 BlockNumber <http://doxygen.postgresql.org/block_8h.html#0be1c1ab88d7f8120e2cd2e8ac2697a1> rblkno = lpageop->btpo_next <http://doxygen.postgresql.org/structBTPageOpaqueData.html#0e96302f6e2aa4203cef0e243362b692>;
> 00592
> 00593 rbuf = _bt_relandgetbuf <http://doxygen.postgresql.org/nbtpage_8c.html#023261cd645fc5e8b4e8517fe9027bd6>(rel, rbuf, rblkno, BT_WRITE <http://doxygen.postgresql.org/nbtree_8h.html#e494b1ec6ecbe7251dfc412a1ec53c1b>);
> 00594 page = BufferGetPage <http://doxygen.postgresql.org/bufmgr_8h.html#fb570c83a17839dabeb75dba7ea8e1a5>(rbuf);
> 00595 lpageop = (BTPageOpaque <http://doxygen.postgresql.org/structBTPageOpaqueData.html>) PageGetSpecialPointer <http://doxygen.postgresql.org/bufpage_8h.html#3be45495654ca1ff61f6ae45805e25f6>(page);
> 00596 if (!P_IGNORE <http://doxygen.postgresql.org/nbtree_8h.html#a8df35238449d00d7e14c3f1ccd3121c>(lpageop))
> 00597 break;
> 00598 if (P_RIGHTMOST <http://doxygen.postgresql.org/nbtree_8h.html#8b5e4857926b514c0f97592bf3344293>(lpageop))
> 00599 elog <http://doxygen.postgresql.org/elog_8h.html#850290250a1449fc513da20ae2ce5ec5>(ERROR <http://doxygen.postgresql.org/elog_8h.html#8fe83ac76edc595f6b98cd4a4127aed5>, "fell off the end of index \"%s\"",
> 00600 RelationGetRelationName <http://doxygen.postgresql.org/rel_8h.html#5e9d450c92f70171110e22ffc678ed04>(rel));
> 00601 }*
>
>
> What is that, i am missing here?
>
> Gokul.
>