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org.apache.derby.iapi.sql.compile
Interface CostEstimate
- All Superinterfaces:
- org.apache.derby.iapi.store.access.StoreCostResult
- public interface CostEstimate
- extends org.apache.derby.iapi.store.access.StoreCostResult
A CostEstimate represents the cost of getting a ResultSet, along with the ordering of rows in the ResultSet, and the estimated number of rows in this ResultSet.
| Method Summary | |
CostEstimate |
add(CostEstimate addend,
CostEstimate retval)
Add this cost estimate to another one. |
CostEstimate |
cloneMe()
Get a copy of this CostEstimate |
double |
compare(CostEstimate other)
Compare this cost estimate with the given cost estimate. |
CostEstimate |
divide(double divisor,
CostEstimate retval)
Divide this cost estimate by a scalar, non-dimensional number. |
boolean |
isUninitialized()
Return whether or not this CostEstimate is uninitialized. |
CostEstimate |
multiply(double multiplicand,
CostEstimate retval)
Multiply this cost estimate by a scalar, non-dimensional number. |
double |
rowCount()
Get the estimated number of rows returned by the ResultSet that this CostEstimate models. |
void |
setCost(CostEstimate other)
Copy the values from the given cost estimate into this one. |
void |
setCost(double cost,
double rowCount,
double singleScanRowCount)
Set the cost for this cost estimate. |
void |
setSingleScanRowCount(double singleRowScanCount)
Set the single scan row count. |
double |
singleScanRowCount()
Get the estimated number of rows returned by a single scan of the ResultSet that this CostEstimate models. |
| Methods inherited from interface org.apache.derby.iapi.store.access.StoreCostResult |
getEstimatedCost, getEstimatedRowCount, setEstimatedCost, setEstimatedRowCount |
| Method Detail |
setCost
public void setCost(double cost,
double rowCount,
double singleScanRowCount)
- Set the cost for this cost estimate.
setCost
public void setCost(CostEstimate other)
- Copy the values from the given cost estimate into this one.
setSingleScanRowCount
public void setSingleScanRowCount(double singleRowScanCount)
- Set the single scan row count.
compare
public double compare(CostEstimate other)
- Compare this cost estimate with the given cost estimate.
add
public CostEstimate add(CostEstimate addend, CostEstimate retval)
- Add this cost estimate to another one. This presumes that any row
ordering is destroyed.
multiply
public CostEstimate multiply(double multiplicand, CostEstimate retval)
- Multiply this cost estimate by a scalar, non-dimensional number. This
presumes that any row ordering is destroyed.
divide
public CostEstimate divide(double divisor, CostEstimate retval)
- Divide this cost estimate by a scalar, non-dimensional number.
rowCount
public double rowCount()
- Get the estimated number of rows returned by the ResultSet that this
CostEstimate models.
singleScanRowCount
public double singleScanRowCount()
- Get the estimated number of rows returned by a single scan of
the ResultSet that this CostEstimate models.
cloneMe
public CostEstimate cloneMe()
- Get a copy of this CostEstimate
isUninitialized
public boolean isUninitialized()
- Return whether or not this CostEstimate is uninitialized.
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| Home >> All >> org >> apache >> derby >> iapi >> sql >> [ compile overview ] | PREV CLASS NEXT CLASS | ||||||||
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SUMMARY: JAVADOC | SOURCE | DOWNLOAD | NESTED | FIELD | CONSTR | METHOD |
DETAIL: FIELD | CONSTR | METHOD | ||||||||