At 07:14 AM 4/7/99 -0700, Patrick Thrapp wrote:
>Jerry Fochtman wrote in message ...
>[snip]
>>
>>Also, if this is a native mode KSAM file, it is better to build the file as
>>part of the same FCOPY step to load it. This is because when NMKsam is
>>loading a file built as a part of the same HPFOPEN, it will periodically
>>leave an open entry as it is writing the data records in the file. In this
>>manner, subsequent opens/writes will more quickly find open slots for new
>>entries. If you simply BUILD the file (which HPFOPENs/FCLOSEs the file)
>and
>>then write the records, this ventilation effect is not done.
>
>
>If I were to convert the following:
>
>Build myksam;rec=-64,64,f,ascii;disc=6400;ksamxl;key=(b,1,15)
>Fcopy from=ksamdata;to=myksam
>
>To:
>
>file myksam,new;rec=-64,64,f,ascii;disc=6400;ksamxl;key=(b,1,15);save
>Fcopy from=ksamdata;to=*myksam
>
>This would enable the ventilation technique? If more keys were defined does
>this ventilation hold true for each key path?
>
Yes, this is the technique as I understand it. The 'ventilation' is in the
data storage portion of the file, and not the b-tree index. In this manner,
when subsequent records are added, open slots are located more quickly.
/jf
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