| org.apache.derby.iapi.sql.compile.OptimizableList
All known Subclasses: org.apache.derby.impl.sql.compile.FromList,
| OptimizableList | | public interface OptimizableList (Code) | | OptimizableList provides services for optimizing a list of
Optimizables (tables) in a query.
|
| Method Summary | |
| public Optimizable | getOptimizable(int n)
Return the nth Optimizable in the list.
Parameters:
n - "index" (0 based) into the list. | | public void | initAccessPaths(Optimizer optimizer)
Init the access paths for these optimizables. | | public boolean | legalJoinOrder(int numTablesInQuery)
Tell whether the join order is legal. | | public boolean | optimizeJoinOrder()
Tell whether the join order should be optimized. | | public void | reOrder(int[] joinOrder)
Set the join order for this list of optimizables. | | public void | setOptimizable(int n, Optimizable optimizable)
Set the nth Optimizable to the specified Optimizable. | | public int | size()
Return the number of Optimizables in the list. | | public boolean | useStatistics()
user can specify that s/he doesn't want statistics to be considered when
optimizing the query. | | public void | verifyProperties(DataDictionary dDictionary)
|
| getOptimizable | | public Optimizable getOptimizable(int n)(Code) | | Return the nth Optimizable in the list.
Parameters:
n - "index" (0 based) into the list. Optimizable The nth Optimizables in the list. |
| initAccessPaths | | public void initAccessPaths(Optimizer optimizer)(Code) | | Init the access paths for these optimizables.
Parameters:
optimizer - The optimizer being used. |
| legalJoinOrder | | public boolean legalJoinOrder(int numTablesInQuery)(Code) | | Tell whether the join order is legal.
|
| optimizeJoinOrder | | public boolean optimizeJoinOrder()(Code) | | Tell whether the join order should be optimized.
|
| reOrder | | public void reOrder(int[] joinOrder)(Code) | | Set the join order for this list of optimizables. The join order is
represented as an array of integers - each entry in the array stands
for the order of the corresponding element in the list. For example,
a joinOrder of {2, 0, 1} means that the 3rd Optimizable in the list
(element 2, since we are zero-based) is the first one in the join
order, followed by the 1st element in the list, and finally by the
2nd element in the list.
This method shuffles this OptimizableList to match the join order.
Obviously, the size of the array must equal the number of elements in
the array, and the values in the array must be between 0 and the
number of elements in the array minus 1, and the values in the array
must be unique.
|
| setOptimizable | | public void setOptimizable(int n, Optimizable optimizable)(Code) | | Set the nth Optimizable to the specified Optimizable.
Parameters:
n - "index" (0 based) into the list.
Parameters:
optimizable - New nth Optimizable. |
| size | | public int size()(Code) | | Return the number of Optimizables in the list.
integer The number of Optimizables in the list. |
| useStatistics | | public boolean useStatistics()(Code) | | user can specify that s/he doesn't want statistics to be considered when
optimizing the query.
|
| verifyProperties | | public void verifyProperties(DataDictionary dDictionary) throws StandardException(Code) | | Verify that the Properties list with optimizer overrides, if specified, is valid
Parameters:
dDictionary - The DataDictionary to use.
exception:
StandardException - Thrown on error |
|
|