That conclusion is beyond what I implied. I merely suggested that, as an SQL INDEX, the optimizer might tend more to its use. As a DDS logical file, the page size is [established by the database as] minimal, optimized for RLA use rather than SQL use. Unless the memory environment is constrained, the optimizer will tend not to choose a DDS LF for random I/O for certain estimates about how much data will be returned.

I have [made] no comment on the efficacy of the data provided by SYSIXADV.

Regards, Chuck

Frank.Kolmann@xxxxxxxxxx wrote:

CRPence wrote:

The displayed file information does not show SQL attribute of
INDEX, so the access path characteristics might not be preferable
for SELECT queries. Perhaps created as an SQL INDEX the results
would change.

If what you say is correct then on V5R4 the SQL optimiser is not looking at LGL files and uses only SQL indexes.
I cannot believe that is true. If it were true we I believe we
would have SERIOUS performance issues.

I still reckon SYSIXADV is broken, probably because it does not
consider LGL files as SQL indexes.

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