IBM 1130 User Manual page 601

Key So.rt vs Reco.rd So.rt
Usually, key so.rting is o.f no. advantage, even with
large disk files, when mo.st o.r all o.f the o.riginal
records are to. be retrieved. Mo.difying the so.rting
and reading schemes to. minimize the to.tal seek
time can have a co.nsiderable effect, but the advan-
tage, generally, still lies with reco.rd so.rting.
Whether a reco.rd so.rt o.r a key so.rt sho.uld be used
to. so.rt a disk file depends largely o.n the ultimate
disPo.sitio.n o.f the so.rted reco.rds.
Sectio.n Subsectio.ns
75 30
I
20
If o.nly an index o.f so.rted reco.rds is necessary,
and few o.f the so.rted reco.rds are actually used,
key so.rting Wo.uld appear to. have the edge.
Exceptio.n repo.rts extracted fro.m the so.rted file
are an example o.f this type o.f situatio.n. On the
the o.ther hand, if mo.st o.r all o.f the original
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reco.rds are to. be retrieved, record so.rting is
preferable to. key So.rting. Mo.reo.ver, the advantage
increases with the size o.f the file.