The attached patch addresses one of the open non-blockers for beta3.
These are tuning points which emerged in testing. The first is more
likely to be helpful. The second may be very important in a few
types of transaction mixes, but I threw in a lot of weasel words and
qualifiers because someone could easily try this to bring down the
transaction retry rate, but suffer a net loss in throughput because
less efficient plans could be chosen. I hope I made that point in a
reasonable fashion, although I'm certainly open to suggestions for
better wording.
-Kevin
*** a/doc/src/sgml/mvcc.sgml
--- b/doc/src/sgml/mvcc.sgml
***************
*** 658,663 **** ERROR: could not serialize access due to read/write
dependencies among transact
--- 658,680 ----
protections automatically provided by Serializable transactions.
</para>
</listitem>
+ <listitem>
+ <para>
+ If you are seeing a lot of serialization failures because multiple
+ page locks are being combined into relation locks, you might want to
+ increase <xref linkend="guc-max-pred-locks-per-transaction">.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ If you are experiencing a lot of serialization failures due to
+ table-scan plans being used, you might want to try reducing
+ <xref linkend="guc-random-page-cost"> and/or increasing
+ <xref linkend="guc-cpu-tuple-cost">. Be sure to weigh any decrease
+ in transaction rollbacks and restarts against any overall change in
+ query execution time.
+ </para>
+ </listitem>
</itemizedlist>
</para>
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