Waited Too Long For Row Cache Enqueue Lock 
Author Message
 Waited Too Long For Row Cache Enqueue Lock
This error message has showed up in our longs a few times over the last few
weeks. I haven't been able to track down any info on this error. Does
anybody have more insight into these entries. We are running Oracle 7.3 on
an HP UNIX box.

Thanks,
Bill



Mon, 25 Jun 2001 03:00:00 GMT
 Waited Too Long For Row Cache Enqueue Lock

Quote:

> This error message has showed up in our longs a few times over the last few
> weeks. I haven't been able to track down any info on this error. Does
> anybody have more insight into these entries. We are running Oracle 7.3 on
> an HP UNIX box.

> Thanks,
> Bill

Specifically what version?  

Thanks
Jim Hamp
Technical Analyst
Oracle Worldwide Support



Mon, 25 Jun 2001 03:00:00 GMT
 Waited Too Long For Row Cache Enqueue Lock
If this is an smp (multi-cpu) box, check the value of
db_block_lru_latches. Sounds like you may be getting some contention for
a latch for the hash buckets that control access to the buffer cache.
Basically, a hash bucket represents a "hashed" address for a dba (data
block address), and these buckets are divided into groups. Pre-7.3, you
could only have one latch to protect the entire group of hash buckets.
Under 7.3, with multiple cpu systems, you can have up to 2 times the
number of cpus. Unfortunately, the default value is 1/2 the number of
cpus, with a minimum of one. Add a line to your initSID.ora file:

db_block_lru_latches = N

where N is twice the number of cpus. Remember that this does nothing for
single processor machines. Anyway, without specific error messages and a
good bstat/estat run it is pretty hard to do more than guess here.

Roger Snowden
Sr. Systems Engineering Specialist
Oracle Corporation

PS- all opinions are mine, personally, and not those of Oracle.

Quote:

> This error message has showed up in our longs a few times over the last few
> weeks. I haven't been able to track down any info on this error. Does
> anybody have more insight into these entries. We are running Oracle 7.3 on
> an HP UNIX box.

> Thanks,
> Bill



Sat, 30 Jun 2001 03:00:00 GMT
 
 [ 3 post ] 

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