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
