Re: LRU latches

Comments inline:

> of the server or "shadow" processes). Latches control both the LRU list for
> the buffer cache and the redo log buffer.

I didn't think that the redo log buffer worked on a Least Recently Used algorithm?!? The log buffer doesn't work on the same principles as the buffer cache so it doesn't need an LRU (or MRU) algorithm does it? While there is a latch for the log buffer, there is not a LRU latch to my knowledge. Can anyone else clarify this? Or is it just me?

> Therefore, the system needs to provide exclusive access to the log buffer to
> an individual process (or processes) and this is done with a latch (it's
> essentially a sephamore).

True, but it's not an LRU latch.  

> > Could someone explain LRU latches and the relationship of these to the
> > LOG_SIMULTANEOUS_COPIES and LOG_SMALL_ENTRY_MAX_SIZE parms? Thanks...

Back to the original post (and if my information is still correct), the LRU latch corresponds to the buffer cache which has nothing to do with the log buffer. Therefore, the LRU latch and the LOG_* parameters have nothing to do with each other.

HTH,
Brian

-- 
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Brian Peasland
Raytheons Systems at
  USGS EROS Data Center
These opinions are my own and do not
necessarily reflect the opinions of my 
company!
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