Re: Company thought DB2 will be better than Oracle.
Date: Sat, 13 Sep 2003 16:00:49 GMT
Message-ID: <RaH8b.434487$Ho3.70347_at_sccrnsc03>
DB2 doesn't do dynamic SQL; it turns dynamic SQL into static SQL and runs
that. If you issue dynamic SQL (and do not commit) then anyone who is
trying to bind after you is hung until you commit. Why? Because the
dynamic sql is bound and a plan is generated, a row is added to the plan
table (thus blocking others from adding to the plan table, until you
commit). Since the concurrency model in db2 is not very concurrent people
issueing dynamic sql lock out those trying to bind their plans in. It
really pisses the developers on the system off. I was at ATT (American
Transtech) years ago with DB2 running on a mainframe and this was a major
problem. So we had to take the application and remove any transactions and
just do everything in an autocommit type of mode.(issue select...;
commit;...etc.)
Binding is a nice and powerfule thing, but the way IBM has implimented it it
really makes DB2 an autocommit only type of database. Ugly real ugly.
Jim
"Larry Edelstein" <lsedels_at_us.ibm.com> wrote in message
news:3F632A76.D3609842_at_us.ibm.com...
> Binding is done to support a feature called Static/Embedded SQL. Static
> SQL is suitable for situations where the SQL is somewhat predictable.
> You develop the SQL as part of the application code and "embed" it into
> the application so to speak. Then, you precompile, compile, link edit,
> and BIND the SQL into what is called a package (which essentially is a
> Load module). The package is an executable ... and when invoked, no
> compilation or bind is necessary ... therefore, the performance tends to
> be significantly better than dynamic SQL.
>
> Larry Edelstein
>
> Neil Truby wrote:
>
> > > Larry Edelstein
> > >
> > > Neil Truby wrote:
> >
> > > > You forgot to mention that lovely old IBM tradition, BINDing.
> > > "Larry Edelstein" <lsedels_at_us.ibm.com> wrote in message
> > news:3F631D4B.899933B5_at_us.ibm.com...
> >
> > > Which many people see as an advantage by the way ...
> >
> > Please expand ..?
>
Received on Sat Sep 13 2003 - 18:00:49 CEST