Hello you can try use plperl as cache http://okbob.blogspot.cz/2007/12/using-shared-as-table-cache-in-plperl.html Regards Pavel Stehule 2012/11/25 Bexley Hall <bexley401@xxxxxxxxx>: > Hi, > > In the absence of query caching AND NOT WANTING TO FORCE > THE APPLICATION TO DO SO EXPLICITLY, I'm looking for ideas > as to how I should "future-safe" the design of some custom > user base types and functions thereon. > > Specifically, I have several computationally expensive > functions that derive their results from specific values of > these base types. *Solely*. (For example, area() when > applied to a given "circle" always yields the same result... > though this is a trivial/inexpensive function, by comparison). > > I can define the base types to set aside space to store > these results and cache them *in* the base type. Then, serve > up these cached results when they are needed, again. With > plan caching, this should (?) reduce the cost of repeated > queries significantly without the need/benefit for caching the > actual query results. (Is that true?) > > To guard against future enhancements to the server (e.g., if > query caching is ever implemented, etc.), I assume that all > such functions should declare themselves as IMMUTABLE? Or, > does my update of the internal representation of the data > values (i.e., to include the cached results of each of these > functions) conflict with this declaration? > > [I am working in a fixed, constrained resource environment so > the idea of explicitly building a temporary table to hold these > results in the absence of a smart query caching strategy is not > possible -- the builder(s) of such tables would have to know > too much about each other to not exhaust the resources available!] > > Thanks! > --don > > > -- > Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
