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Oracle
Metric hard parse (sharing criteria) elapsed time
Oracle Tips by Burleson Consulting
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The
hard parse (sharing criteria) elapsed time
Oracle metric is the
amount
of elapsed time spent performing SQL hard parses when the hard parse
resulted from not being able to share an existing cursor in the SQL
cache.
For more details see:
Oracle hard-parse vs.
soft parse
A hard parse is when your
SQL must be re-loaded into the shared pool.
A hard parse is worse than a soft parse because of the overhead
involved in shared pool RAM allocation and memory management. Once
loaded, the SQL must then be completely re-checked for syntax &
semantics and an executable generated.
Excessive hard parsing can occur when your shared_pool_size
is too small (and reentrant SQL is paged out), or when you have
non-reusable SQL statements without host variables.
Also, it
is pointed out in a
Rampant Techpress information page that "the
V$SESS_TIME_MODEL view provides a window into," the hard
parse (sharing criteria) elapsed time metric.
This, and many other Oracle performance metrics are discussed in
my book "Oracle
Tuning" by Rampant TechPress. You can buy it directly from
the publisher and save 30% at this link:
http://www.rampant-books.com/book_2005_1_awr_proactive_tuning.htm
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