RE: investigating deadlocks - wait-for-graph

From: Amaral, Rui <>
Date: Thu, 25 Nov 2010 12:13:11 -0500
Message-ID: <AD1FD82AC6BFBE4C8913E32286D9C70D0812ED9F40_at_EX7T2-SV05.TDBFG.COM>

Have you seen the following:

Deadlock Error Not in Alert.log and No Trace File Generated on OPS or RAC [ID 262226.1]

Explains it as:

These values are:
<BLOCKED|BLOCKER> <lockp> <cvt|held mode> <res name> <pid|did|txn_id> <node>

The second to last field () could be a pid or the txn id depending on whether we have an XID based deadlock search flag.  

Rui Amaral
Database Administrator
TD Bank Financial Group
220 Bay St., 11th Floor
Toronto, ON, CA, M5K1A2
(bb) (647) 204-9106  

-----Original Message-----

From: [] On Behalf Of D'Hooge Freek Sent: Thursday, November 25, 2010 11:57 AM To:
Subject: investigating deadlocks - wait-for-graph


I have a rac database ( on Redhat linux 4.6), which reports daily 5 or 6 times a global enqueue deadlock detected.

For my investigations I'm trying to understand the wait-for-graph, but information seems to be limited.

Global Wait-For-Graph(WFG) at ddTS[0.1062] : BLOCKED 0x1d4929550 5 wq 2 cvtops x1 [0x1c001b][0x19644],[TX] [4A000-0001-00000D8A] 0 BLOCKER 0x1b81f25d0 5 wq 1 cvtops x8 [0x1c001b][0x19644],[TX] [B3000-0002-00000C60] 1 BLOCKED 0x1d4ac8e00 5 wq 2 cvtops x1 [0x20028][0x48c3e],[TX] [B3000-0002-00000C60] 1 BLOCKER 0x1d48ee550 5 wq 1 cvtops x8 [0x20028][0x48c3e],[TX] [4A000-0001-00000D8A] 0

If my information is correct, the last column is the rac node and the before last is the transaction id.

wq 1 is the grant queue and wq 2 is the convert queue.

But what is the second and third column (lock mode?) And what about the other fields?

Any pointers?

Kind regards,

Freek D'Hooge
Oracle Database Administrator
tel +32(0)3 451 23 82


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-- Received on Thu Nov 25 2010 - 11:13:11 CST

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