Re: Deadlock on overflow segment !? (for experts)

Ora-04020 is a KGL deadlock, not a data deadlock, and can indicate an internal coding error on the part of the Oracle developers.

4020 deadlocks could appear with partitioned IOTs in earlier versions of 8.1 if you split two different partitions of the same partitioned IOT at the same time. Would this be consistent with your '2 or 3 times per day' ?

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"Andras Kovacs" <andkovacs_at_yahoo.com> wrote in message
news:412ebb69.0307210414.47dbc323_at_posting.google.com...


> Hi,

>

> I am having a curious issue with an Index oraganized PARTITIONED

> table. There is a single application that inserts data into this

table


> on regular basis (every 5 min). Then sometimes we are getting error

> with the following indication:

>

> ORA-04020: deadlock detected while trying to lock object

> USER.SYS_IOT_OVER_6840.

>

> I have no control over overflow segments.

> I read several articles on deadlocks but none of them handle IOT

table


> deadlock issues. The problem is difficult to reproduce but happens

2-3


> times a day and causes major problem in our system.

>

> Is there a way to fine tune some table parameters avoid this

situation


> ?

>

> The table doesn't have much attributs, I could put all of them into

> the index. (Though read performance could take a hit).

>

> I heared that there is a deadlock issue when IOT is partitioned.

> Is there an article on this ?