Re: Database I/O Modernization

On Sat, Sep 16, 2017 at 12:49 AM, Birgitta Hauser <Hauser@xxxxxxxxxxxxxxx>
wrote:

Nathan,

not sure where your information "SQL uses RLA" is from.
I don't think you are deeply enough involved in the database, SQL etc.
development at IBM, for knowing that. It can only be a guess.
I don't know either.

My information comes from IBM publications. I don't want to take the time
to cite references because there are so many. Moreover, it is kind of
frustrating to "prove" something that is actually intuitive if you think
about it. Data in Db2 for i is stored in files that contain "records". How
else would the SQE access "records" without using RLA?

... but it was Barbara Morris who told me that native I/O access uses the

SQE (since Release 7.2)

I doubt that. Perhaps something was lost in your translation of the English
language?

and Scott Forstie confirmed that all database access is performed by the
SQE (except an QAQQINI option is set to go back to the CQE).

The context for Scott Forstie's remark was probably in reference to IBM's
recent migration of query interfaces such as OPNQRYF from the CQE to the
SQE.

The SQE uses RLA to access files. The SQE performs a lot of logic related
to interpreting what the SQL programmer is requesting, determining the best
way of providing it, and actually fulfilling the request. There is a lot
entailed under the covers of that language environment and query engine
that IBM hasn't revealed. But the actual I/O is performed using RLA.