SAS Scalable Performance Data Server 4.5, Руководство администратора

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+----<Table1,ID>: sobs=25001 eobs=50000 (Sorted)
+-------unique_keys=25000, max_occurance=1
+-------obs=25000, joinobs=25000, rangepct=100.00
+----<Table2,ID>: sobs=-1 eobs=0
+-------unique_keys=0, max_occurance=0
+-------obs=2, joinobs=0, rangepct= 0.00
+-Range 2
+----<Table1,ID>: sobs=50001 eobs=75000 (Sorted)
+-------unique_keys=25000, max_occurance=1
+-------obs=25000, joinobs=25000, rangepct=100.00
+----<Table2,ID>: sobs=-1 eobs=0
+-------unique_keys=0, max_occurance=0
+-------obs=2, joinobs=0, rangepct= 0.00
+-Range 3
+----<Table1,ID>: sobs=75001 eobs=100000 (Sorted)
+-------unique_keys=25000, max_occurance=1
+-------obs=25000, joinobs=25000, rangepct=100.00
+----<Table2,ID>: sobs=-1 eobs=0
+-------unique_keys=0, max_occurance=0
+-------obs=2, joinobs=0, rangepct= 0.00
Table Table1, Column ID average range join row pct=100.00
Table Table2, Column ID average range join row pct= 25.00
Ixutil completed successfully
Delete the Join Index
Use the
-deljidx
option of the ixutil command to delete the join index.
> ixutil -deljidx Table1,ID Table2,ID
-libpath /tmp
SAS Scalable Performance Data Server
4.5(TS M0) Build(Feb 26 2009, 11:50:08)
Index File Utility
Copyright (c) 1996-2009 by SAS Institute Inc, Cary NC 27513 USA
Ixutil completed successfully
Parallel join work units are based on the ranges of the join keys. For example, range 0 will
join ranges 1 through 100, range 1 can join range 101 to 200, and so on Ranges can overlap
observations if the tables are not sorted by the join key. The more sorted the table is by the
join key, the fewer rows a range work unit will need to read, in order to gather all of the
rows in its range. The overall performance of the parallel join index depends on how well
the table is sorted by the join key. The stronger the join key sort, the better the performance.
If a range work unit has a range percentage of 0 for either table, then there are no rows in
the table for that range, and that range will be discarded by a parallel work thread.
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Chapter 17 • SPD Server Index Utility Ixutil