From: | Lucas Lersch <lucaslersch(at)gmail(dot)com> |
---|---|
To: | pgsql-hackers(at)postgresql(dot)org |
Subject: | Buffer Requests Trace |
Date: | 2014-10-14 16:08:31 |
Message-ID: | CAGR3jZAy3ckTu48gp3CmeQ8riB10Mo+jHYy_XMLjwx=DsruTug@mail.gmail.com |
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Lists: | pgsql-hackers |
Hello,
I changed the buffer manager code in order to generate a trace of page
requests from the buffer manager perspective. In summary, whenever
ReleaseBuffer() or ReleaseAndReadBuffer() are called, I print the page
currently being released which is identified by the tuple (tableSpace,
dbNode, relationNode, blockNumber).
I am now running a tpcc benchmark from http://oltpbenchmark.com/
Initially I create and load the database with a scale factor of 64. This
sums up to a database of around 6.7GB (~ 800k pages). Then I execute the
tpcc benchmark for 1 minute with only 1 terminal. Finally I analyse the
trace of the buffer requests made by the execution of the benchmark only
(creation and loading not considered).
Unfortunately, in the generated trace with over 2 million buffer requests,
only ~14k different pages are being accessed, out of the 800k of the whole
database. Am I missing something here?
Best regards.
--
Lucas Lersch
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