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org.apache.derby.iapi.sql.compile
Interface Optimizer
- public interface Optimizer
Optimizer provides services for optimizing a query. RESOLVE: o Need to figure out what to do about subqueries, figuring out their attachment points and how to communicate them back to the caller.
| Method Summary | |
void |
considerCost(Optimizable optimizable,
OptimizablePredicateList predList,
CostEstimate estimatedCost,
CostEstimate outerCost)
Consider the cost of the given optimizable. |
void |
costOptimizable(Optimizable optimizable,
org.apache.derby.iapi.sql.dictionary.TableDescriptor td,
org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor cd,
OptimizablePredicateList predList,
CostEstimate outerCost)
Cost the current Optimizable with the specified OPL. |
void |
costPermutation()
Cost the current permutation. |
org.apache.derby.iapi.sql.dictionary.DataDictionary |
getDataDictionary()
Return the DataDictionary that the Optimizer is using. |
JoinStrategy |
getJoinStrategy(int whichStrategy)
Gets a join strategy by number (zero-based). |
JoinStrategy |
getJoinStrategy(java.lang.String whichStrategy)
Gets a join strategy by name. |
int |
getLevel()
Get the level of this optimizer. |
int |
getMaxMemoryPerTable()
|
boolean |
getNextDecoratedPermutation()
Iterate through the "decorated permutations", returning false when they are exhausted. |
boolean |
getNextPermutation()
Iterate through the permutations, returning false when the permutations are exhausted. |
int |
getNumberOfJoinStrategies()
Get the number of join strategies supported by this optimizer. |
CostEstimate |
getOptimizedCost()
Get the estimated cost of the optimized query |
void |
modifyAccessPaths()
Modify the access path for each Optimizable, as necessary. |
CostEstimate |
newCostEstimate()
Get a new CostEstimate object |
void |
setOuterRows(double outerRowCount)
Set the estimated number of outer rows - good for optimizing nested optimizables like subqueries and join nodes. |
int |
tableLockThreshold()
Get the maximum number of estimated rows touched in a table before we decide to open the table with table locking (as opposed to row locking. |
void |
trace(int traceFlag,
int intParam1,
int intParam2,
double doubleParam,
java.lang.Object objectParam1)
Optimizer trace. |
double |
uniqueJoinWithOuterTable(OptimizablePredicateList predList)
Tells whether any of the tables outer to the current one has a uniqueness condition on the given predicate list, and if so, how many times each unique key can be seen by the current table. |
boolean |
useStatistics()
If statistics should be considered by the optimizer while optimizing a query. |
| Field Detail |
MODULE
public static final java.lang.String MODULE
- Module name for the monitor's module locating system.
- See Also:
- Constant Field Values
JOIN_ORDER_OPTIMIZATION
public static final java.lang.String JOIN_ORDER_OPTIMIZATION
- Property name for controlling whether to do join order optimization.
- See Also:
- Constant Field Values
RULE_BASED_OPTIMIZATION
public static final java.lang.String RULE_BASED_OPTIMIZATION
- Property name for controlling whether to do rule-based optimization,
as opposed to cost-based optimization.
- See Also:
- Constant Field Values
NO_TIMEOUT
public static final java.lang.String NO_TIMEOUT
- Property name for controlling whether the optimizer ever times out
while optimizing a query and goes with the best plan so far.
- See Also:
- Constant Field Values
MAX_MEMORY_PER_TABLE
public static final java.lang.String MAX_MEMORY_PER_TABLE
- Property name for controlling the maximum size of memory (in KB)
the optimizer can use for each table. If an access path takes
memory larger than that size for a table, the access path is skipped.
Default is 1024 (KB).
- See Also:
- Constant Field Values
USE_STATISTICS
public static final java.lang.String USE_STATISTICS
- Property name for disabling statistics use for all queries.
- See Also:
- Constant Field Values
NORMAL_PLAN
public static final int NORMAL_PLAN
- Indicates a "normal" plan that is not optimized to do sort avoidance
- See Also:
- Constant Field Values
SORT_AVOIDANCE_PLAN
public static final int SORT_AVOIDANCE_PLAN
- Indicates a sort-avoidance plan
- See Also:
- Constant Field Values
STARTED
public static final int STARTED
- See Also:
- Constant Field Values
TIME_EXCEEDED
public static final int TIME_EXCEEDED
- See Also:
- Constant Field Values
NO_TABLES
public static final int NO_TABLES
- See Also:
- Constant Field Values
COMPLETE_JOIN_ORDER
public static final int COMPLETE_JOIN_ORDER
- See Also:
- Constant Field Values
COST_OF_SORTING
public static final int COST_OF_SORTING
- See Also:
- Constant Field Values
NO_BEST_PLAN
public static final int NO_BEST_PLAN
- See Also:
- Constant Field Values
MODIFYING_ACCESS_PATHS
public static final int MODIFYING_ACCESS_PATHS
- See Also:
- Constant Field Values
SHORT_CIRCUITING
public static final int SHORT_CIRCUITING
- See Also:
- Constant Field Values
SKIPPING_JOIN_ORDER
public static final int SKIPPING_JOIN_ORDER
- See Also:
- Constant Field Values
ILLEGAL_USER_JOIN_ORDER
public static final int ILLEGAL_USER_JOIN_ORDER
- See Also:
- Constant Field Values
USER_JOIN_ORDER_OPTIMIZED
public static final int USER_JOIN_ORDER_OPTIMIZED
- See Also:
- Constant Field Values
CONSIDERING_JOIN_ORDER
public static final int CONSIDERING_JOIN_ORDER
- See Also:
- Constant Field Values
TOTAL_COST_NON_SA_PLAN
public static final int TOTAL_COST_NON_SA_PLAN
- See Also:
- Constant Field Values
TOTAL_COST_SA_PLAN
public static final int TOTAL_COST_SA_PLAN
- See Also:
- Constant Field Values
TOTAL_COST_WITH_SORTING
public static final int TOTAL_COST_WITH_SORTING
- See Also:
- Constant Field Values
CURRENT_PLAN_IS_SA_PLAN
public static final int CURRENT_PLAN_IS_SA_PLAN
- See Also:
- Constant Field Values
CHEAPEST_PLAN_SO_FAR
public static final int CHEAPEST_PLAN_SO_FAR
- See Also:
- Constant Field Values
PLAN_TYPE
public static final int PLAN_TYPE
- See Also:
- Constant Field Values
COST_OF_CHEAPEST_PLAN_SO_FAR
public static final int COST_OF_CHEAPEST_PLAN_SO_FAR
- See Also:
- Constant Field Values
SORT_NEEDED_FOR_ORDERING
public static final int SORT_NEEDED_FOR_ORDERING
- See Also:
- Constant Field Values
REMEMBERING_BEST_JOIN_ORDER
public static final int REMEMBERING_BEST_JOIN_ORDER
- See Also:
- Constant Field Values
SKIPPING_DUE_TO_EXCESS_MEMORY
public static final int SKIPPING_DUE_TO_EXCESS_MEMORY
- See Also:
- Constant Field Values
COST_OF_N_SCANS
public static final int COST_OF_N_SCANS
- See Also:
- Constant Field Values
HJ_SKIP_NOT_MATERIALIZABLE
public static final int HJ_SKIP_NOT_MATERIALIZABLE
- See Also:
- Constant Field Values
HJ_SKIP_NO_JOIN_COLUMNS
public static final int HJ_SKIP_NO_JOIN_COLUMNS
- See Also:
- Constant Field Values
HJ_HASH_KEY_COLUMNS
public static final int HJ_HASH_KEY_COLUMNS
- See Also:
- Constant Field Values
CALLING_ON_JOIN_NODE
public static final int CALLING_ON_JOIN_NODE
- See Also:
- Constant Field Values
CONSIDERING_JOIN_STRATEGY
public static final int CONSIDERING_JOIN_STRATEGY
- See Also:
- Constant Field Values
REMEMBERING_BEST_ACCESS_PATH
public static final int REMEMBERING_BEST_ACCESS_PATH
- See Also:
- Constant Field Values
NO_MORE_CONGLOMERATES
public static final int NO_MORE_CONGLOMERATES
- See Also:
- Constant Field Values
CONSIDERING_CONGLOMERATE
public static final int CONSIDERING_CONGLOMERATE
- See Also:
- Constant Field Values
SCANNING_HEAP_FULL_MATCH_ON_UNIQUE_KEY
public static final int SCANNING_HEAP_FULL_MATCH_ON_UNIQUE_KEY
- See Also:
- Constant Field Values
ADDING_UNORDERED_OPTIMIZABLE
public static final int ADDING_UNORDERED_OPTIMIZABLE
- See Also:
- Constant Field Values
CHANGING_ACCESS_PATH_FOR_TABLE
public static final int CHANGING_ACCESS_PATH_FOR_TABLE
- See Also:
- Constant Field Values
TABLE_LOCK_NO_START_STOP
public static final int TABLE_LOCK_NO_START_STOP
- See Also:
- Constant Field Values
NON_COVERING_INDEX_COST
public static final int NON_COVERING_INDEX_COST
- See Also:
- Constant Field Values
ROW_LOCK_ALL_CONSTANT_START_STOP
public static final int ROW_LOCK_ALL_CONSTANT_START_STOP
- See Also:
- Constant Field Values
ESTIMATING_COST_OF_CONGLOMERATE
public static final int ESTIMATING_COST_OF_CONGLOMERATE
- See Also:
- Constant Field Values
LOOKING_FOR_SPECIFIED_INDEX
public static final int LOOKING_FOR_SPECIFIED_INDEX
- See Also:
- Constant Field Values
MATCH_SINGLE_ROW_COST
public static final int MATCH_SINGLE_ROW_COST
- See Also:
- Constant Field Values
COST_INCLUDING_EXTRA_1ST_COL_SELECTIVITY
public static final int COST_INCLUDING_EXTRA_1ST_COL_SELECTIVITY
- See Also:
- Constant Field Values
CALLING_NEXT_ACCESS_PATH
public static final int CALLING_NEXT_ACCESS_PATH
- See Also:
- Constant Field Values
TABLE_LOCK_OVER_THRESHOLD
public static final int TABLE_LOCK_OVER_THRESHOLD
- See Also:
- Constant Field Values
ROW_LOCK_UNDER_THRESHOLD
public static final int ROW_LOCK_UNDER_THRESHOLD
- See Also:
- Constant Field Values
COST_INCLUDING_EXTRA_START_STOP
public static final int COST_INCLUDING_EXTRA_START_STOP
- See Also:
- Constant Field Values
COST_INCLUDING_EXTRA_QUALIFIER_SELECTIVITY
public static final int COST_INCLUDING_EXTRA_QUALIFIER_SELECTIVITY
- See Also:
- Constant Field Values
COST_INCLUDING_EXTRA_NONQUALIFIER_SELECTIVITY
public static final int COST_INCLUDING_EXTRA_NONQUALIFIER_SELECTIVITY
- See Also:
- Constant Field Values
COST_OF_NONCOVERING_INDEX
public static final int COST_OF_NONCOVERING_INDEX
- See Also:
- Constant Field Values
REMEMBERING_JOIN_STRATEGY
public static final int REMEMBERING_JOIN_STRATEGY
- See Also:
- Constant Field Values
REMEMBERING_BEST_ACCESS_PATH_SUBSTRING
public static final int REMEMBERING_BEST_ACCESS_PATH_SUBSTRING
- See Also:
- Constant Field Values
REMEMBERING_BEST_SORT_AVOIDANCE_ACCESS_PATH_SUBSTRING
public static final int REMEMBERING_BEST_SORT_AVOIDANCE_ACCESS_PATH_SUBSTRING
- See Also:
- Constant Field Values
REMEMBERING_BEST_UNKNOWN_ACCESS_PATH_SUBSTRING
public static final int REMEMBERING_BEST_UNKNOWN_ACCESS_PATH_SUBSTRING
- See Also:
- Constant Field Values
COST_OF_CONGLOMERATE_SCAN1
public static final int COST_OF_CONGLOMERATE_SCAN1
- See Also:
- Constant Field Values
COST_OF_CONGLOMERATE_SCAN2
public static final int COST_OF_CONGLOMERATE_SCAN2
- See Also:
- Constant Field Values
COST_OF_CONGLOMERATE_SCAN3
public static final int COST_OF_CONGLOMERATE_SCAN3
- See Also:
- Constant Field Values
COST_OF_CONGLOMERATE_SCAN4
public static final int COST_OF_CONGLOMERATE_SCAN4
- See Also:
- Constant Field Values
COST_OF_CONGLOMERATE_SCAN5
public static final int COST_OF_CONGLOMERATE_SCAN5
- See Also:
- Constant Field Values
COST_OF_CONGLOMERATE_SCAN6
public static final int COST_OF_CONGLOMERATE_SCAN6
- See Also:
- Constant Field Values
COST_OF_CONGLOMERATE_SCAN7
public static final int COST_OF_CONGLOMERATE_SCAN7
- See Also:
- Constant Field Values
COST_INCLUDING_COMPOSITE_SEL_FROM_STATS
public static final int COST_INCLUDING_COMPOSITE_SEL_FROM_STATS
- See Also:
- Constant Field Values
COMPOSITE_SEL_FROM_STATS
public static final int COMPOSITE_SEL_FROM_STATS
- See Also:
- Constant Field Values
COST_INCLUDING_STATS_FOR_INDEX
public static final int COST_INCLUDING_STATS_FOR_INDEX
- See Also:
- Constant Field Values
| Method Detail |
getNextPermutation
public boolean getNextPermutation()
throws org.apache.derby.iapi.error.StandardException
- Iterate through the permutations, returning false when the permutations
are exhausted.
NOTE - Implementers are responsible for hiding tree pruning of permutations
behind this method call.
getNextDecoratedPermutation
public boolean getNextDecoratedPermutation()
throws org.apache.derby.iapi.error.StandardException
- Iterate through the "decorated permutations", returning false when they
are exhausted.
NOTE - Implementers are responsible for hiding tree pruning of access
methods behind this method call.
costPermutation
public void costPermutation()
throws org.apache.derby.iapi.error.StandardException
- Cost the current permutation.
Caller is responsible for pushing all predicates which can be evaluated
prior to costing.
costOptimizable
public void costOptimizable(Optimizable optimizable, org.apache.derby.iapi.sql.dictionary.TableDescriptor td, org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor cd, OptimizablePredicateList predList, CostEstimate outerCost) throws org.apache.derby.iapi.error.StandardException
- Cost the current Optimizable with the specified OPL.
Caller is responsible for pushing all predicates which can be evaluated
prior to costing.
considerCost
public void considerCost(Optimizable optimizable, OptimizablePredicateList predList, CostEstimate estimatedCost, CostEstimate outerCost) throws org.apache.derby.iapi.error.StandardException
- Consider the cost of the given optimizable. This method is like
costOptimizable, above, but it is used when the Optimizable does
not need help from the optimizer in costing the Optimizable (in practice,
all Optimizables except FromBaseTable use this method.
Caller is responsible for pushing all predicates which can be evaluated
prior to costing.
getDataDictionary
public org.apache.derby.iapi.sql.dictionary.DataDictionary getDataDictionary()
- Return the DataDictionary that the Optimizer is using.
This is useful when an Optimizable needs to call optimize() on
a child ResultSetNode.
modifyAccessPaths
public void modifyAccessPaths()
throws org.apache.derby.iapi.error.StandardException
- Modify the access path for each Optimizable, as necessary. This includes
things like adding result sets to translate from index rows to base rows.
newCostEstimate
public CostEstimate newCostEstimate()
- Get a new CostEstimate object
getOptimizedCost
public CostEstimate getOptimizedCost()
- Get the estimated cost of the optimized query
setOuterRows
public void setOuterRows(double outerRowCount)
- Set the estimated number of outer rows - good for optimizing nested
optimizables like subqueries and join nodes.
getNumberOfJoinStrategies
public int getNumberOfJoinStrategies()
- Get the number of join strategies supported by this optimizer.
tableLockThreshold
public int tableLockThreshold()
- Get the maximum number of estimated rows touched in a table before
we decide to open the table with table locking (as opposed to row
locking.
getJoinStrategy
public JoinStrategy getJoinStrategy(int whichStrategy)
- Gets a join strategy by number (zero-based).
getJoinStrategy
public JoinStrategy getJoinStrategy(java.lang.String whichStrategy)
- Gets a join strategy by name. Returns null if not found.
The look-up is case-insensitive.
trace
public void trace(int traceFlag,
int intParam1,
int intParam2,
double doubleParam,
java.lang.Object objectParam1)
- Optimizer trace.
getLevel
public int getLevel()
- Get the level of this optimizer.
uniqueJoinWithOuterTable
public double uniqueJoinWithOuterTable(OptimizablePredicateList predList) throws org.apache.derby.iapi.error.StandardException
- Tells whether any of the tables outer to the current one
has a uniqueness condition on the given predicate list,
and if so, how many times each unique key can be seen by
the current table.
useStatistics
public boolean useStatistics()
- If statistics should be considered by the optimizer while optimizing
a query. The user may disable the use of statistics by setting the
property derby.optimizer.useStatistics or by using the property
useStatistics in a query.
getMaxMemoryPerTable
public int getMaxMemoryPerTable()
|
|||||||||
| Home >> All >> org >> apache >> derby >> iapi >> sql >> [ compile overview ] | PREV CLASS NEXT CLASS | ||||||||
|
SUMMARY: JAVADOC | SOURCE | DOWNLOAD | NESTED | FIELD | CONSTR | METHOD |
DETAIL: FIELD | CONSTR | METHOD | ||||||||