org.apache.derby.impl.store.access.sort
Class MergeSortInfo
java.lang.Object
org.apache.derby.impl.store.access.sort.MergeSortInfo
- All Implemented Interfaces:
- SortInfo
class MergeSortInfo
- extends java.lang.Object
- implements SortInfo
This object provides performance information related to a sort.
The information is accumulated during operations on a SortController() and
then copied into this object and returned by a call to
SortController.getSortInfo().
- See Also:
SortController.getSortInfo()
Method Summary |
java.util.Properties |
getAllSortInfo(java.util.Properties prop)
Return all information gathered about the sort. |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
stat_sortType
private java.lang.String stat_sortType
- Performance counters ...
stat_numRowsInput
private int stat_numRowsInput
stat_numRowsOutput
private int stat_numRowsOutput
stat_numMergeRuns
private int stat_numMergeRuns
stat_mergeRunsSize
private java.util.Vector stat_mergeRunsSize
MergeSortInfo
MergeSortInfo(MergeInserter sort)
getAllSortInfo
public java.util.Properties getAllSortInfo(java.util.Properties prop)
throws StandardException
- Return all information gathered about the sort.
This routine returns a list of properties which contains all information
gathered about the sort. If a Property is passed in, then that property
list is appended to, otherwise a new property object is created and
returned.
Not all sorts may support all properties, if the property is not
supported then it will not be returned. The following is a list of
properties that may be returned:
sortType
- type of the sort being performed:
internal
external
numRowsInput
- the number of rows input to the sort. This
number includes duplicates.
numRowsOutput
- the number of rows to be output by the sort. This number
may be different from numRowsInput since duplicates may not
be output.
numMergeRuns
- the number of merge runs for the sort.
Applicable to external sorts only.
Note: when a SortController is closed, numMergeRuns may increase by 1, to
reflect the additional merge run that may be created for
any data still in the sort buffer.
mergeRunsSize
- the size (number of rows) of each merge run for the sort.
Applicable to external sorts only.
e.g. [3,3,2] indicates 3 merge runs, where the first two runs
have 3 rows each, and the last run has 2 rows.
Note: when a SortController is closed, this vector may get an
additional element, to reflect the additional merge run that
may be created for any data still in the sort buffer.
NOTE - this list will be expanded as more information about the sort
is gathered and returned.
- Specified by:
getAllSortInfo
in interface SortInfo
- Parameters:
prop
- Property list to fill in.
- Throws:
StandardException
- Standard exception policy.
Apache Derby V10.6 Internals - Copyright © 2004,2007 The Apache Software Foundation. All Rights Reserved.