2011/6/19 Robert Haas <robertmhaas@gmail.com>:
> On Sat, Jun 18, 2011 at 9:21 AM, Pavel Stehule <pavel.stehule@gmail.com> wrote:
>> Is this profile expected?
>
> I've certainly seen profiles before where the catcache overhead was
> significant. I don't think that I've seen SearchCatCache() quite this
> high on any of the profiling I've done, but then again I don't tend to
> profile the same things you do, so maybe that's not surprising. I
> think the interesting question is probably "where are all those calls
> coming from?" and "can we optimize any of them away?" rather than "how
> do we make SearchCatCache() run faster?". I would be willing to bet
> money that the latter is largely an exercise in futility.
I would not to attack on SearchCatCache. This is relative new area for
me, so I just asked.
The "suspect" part should be inside exec_assign_value
case PLPGSQL_DTYPE_ARRAYELEM: {
....
/* Fetch current value of array datum */
exec_eval_datum(estate,target,
&arraytypeid, &arraytypmod,
&oldarraydatum, &oldarrayisnull);
/* If target is domain over array,
reduce to base type */ arraytypeid =
getBaseTypeAndTypmod(arraytypeid, &arraytypmod);
/* ... and identify the element type */ arrayelemtypeid =
get_element_type(arraytypeid); if (!OidIsValid(arrayelemtypeid))
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("subscripted object is not an array")));
get_typlenbyvalalign(arrayelemtypeid,
&elemtyplen,
&elemtypbyval,
&elemtypalign); arraytyplen = get_typlen(arraytypeid);
so any update of array means a access to CatCache.
These data should be cached in some referenced data type info
structure and should be accessed via new exec_eval_array_datum()
function.
Regards
Pavel Stehule
>
> --
> Robert Haas
> EnterpriseDB: http://www.enterprisedb.com
> The Enterprise PostgreSQL Company
>
