Ok, so that's what I thought. But why then wouldn't
soft+hard=executions (numbers from bstat/estat).
Thanks,
Scott
>In article <91r65p$li5$1_at_nnrp1.deja.com>,
> yong321_at_yahoo.com wrote:
> It's not true that "soft parse means that the application is using
bind
> variables". Soft parse means the SQL statement is still "parse"d by
the
> SQL engine and a search in library cache returns the parsed form
> successfully. I quote the word "parse" because I believe all Oracle
> does in this step is simply calculating the hash value of the
statement
> and find the SQL statement in library cache based on the hash value.
If
> it does not find it, a hard parse is performed to generate the ready-
to-
> execute code.
>
> From http://www.ixora.com.au/q+a/0008/29164243.htm:
>
> * session cursor cache hits = no library cache access required
> * shared cursor cache hits = library cache hits = soft parses
> * shared cursor cache misses = library cache misses = hard parses
>
> This tells us that, if you set session_cached_cursors to a non-zero
> number (which you should), the library cache is not hit at all. The
> parsed form of the SQL may be in your UGA, which is a very good thing!
>
> In any case, using bind variables is good, unless you use column
> histograms.
>
> Yong Huang
> yong321_at_yahoo.com
>
> In article <91r2gu$i7b$1_at_nnrp1.deja.com>,
> jdarrah_co_at_my-deja.com wrote:
> > Soft parse means that the application is using bind variables. A
soft
> > parse occurres when two users request either a) the exact same
> > statement or b) the statements differ only in their bind variables.
> > When a soft parse occures only the permissions are checked. The
> > execution plan is resued and the syntax of the sql is not so a soft
> > parse is much less cpu intensive than a hard parse. Your soft to
hard
> > parse ratio looks good.
> >
> > In article <91qulm$eo0$1_at_nnrp1.deja.com>,
> > H2oStyle <sdempsey_at_my-deja.com> wrote:
> > > I'm working with a system running Ora 8.1.5.00 Ent. Ed.
> > > bstat/estat reports:
> > > 108,572 total parses and
> > > 3,572 hard parses
> > > for 224632 executions of SQL statements
> > >
> > > I'm clear on what hard parses are, but what are the others?
> > > Or rather what is going on during a non hard parse?
> > >
> > > And is there something to infer from the ratio of these "soft"
parses
> > > to executes(96.6%)? FYI, the application is not using bind vars,
yet.
> > > I read somewhere that Oracle reparses every sql statement that has
> > > literals in the where clause. If that's true, I wonder if they
> > > meant "soft" vs hard parse?
> > >
> > > Thanks in advance,
> > > Scott
>
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Received on Wed Dec 20 2000 - 22:10:26 CST
