21 Extensible Optimizer Interface

Consider the functions and procedures that comprise the interface to the extensible optimizer.

21.1 Extensible Optimizer Interface

The extensible optimizer interfaces support working with partitioned tables and domain indexes. This is accomplished in two ways:

• Additional attributes have been added to some system-defined object types that are parameters to the ODCIStats interface methods. For example, the ODCIColInfo type is enhanced to add information about the column's partition.

• Arguments or semantics of the arguments have changed for some ODCIStats methods.

Note that you must update your code for ODCIStats2 version of the ODCIStats interfaces to use your statistics type with an indextype that implements the ODCIIndex2 version of the extensible indexing interfaces.

21.1.1 Using Statistics Functions in an Extensible Optimizer Interface

Consider an example of how the statistics functions might be used.

1. In the schema HR, we define the following operators:

   CREATE OPERATOR Contains binding (VARCHAR2(4000), VARCHAR2(30))
      RETURN NUMBER USING Contains_fn;
   
   CREATE TYPE stat1 (
      ...,
      STATIC FUNCTION ODCIStatsSelectivity(pred ODCIPredInfo, sel OUT NUMBER,
         args ODCIArgDescList, start NUMBER, stop NUMBER, doc VARCHAR2(4000),
         key VARCHAR2(30)) return NUMBER,
      STACTIC FUNCTION ODCIStatsFunctionCost(func ODCIFuncInfo, cost OUT
         ODCICost, args ODCIArgDescList, doc VARCHAR2(4000), key VARCHAR2(30))
         return NUMBER,
      STATIC FUNCTION ODCIStatsIndexCost(ia ODCIIndexInfo, sel NUMBER,
         cost OUT ODCICost, qi ODCIQueryInfo, pred ODCIPredInfo,
         args ODCIArgDescList, start NUMBER, stop NUMBER,
         key VARCHAR2(30)) return NUMBER,
      ...
   );
   
   CREATE TABLE T (resume VARCHAR2(4000));
   
   CREATE INDEX T_resume on T(resume) INDEXTYPE IS indtype;
   
   ASSOCIATE STATISTICS WITH FUNCTIONS Contains_fn USING stat1;
   
   ASSOCIATE STATISTICS WITH INDEXTYPE indtype USING stat1 
      WITH SYSTEM MANAGED STORAGE TABLES;
   

2. The optimizer encounters the query

   SELECT * FROM T WHERE Contains(resume, 'ORACLE') = 1,
   

3. It computes the selectivity of the predicate by invoking the user-defined selectivity function for the functional implementation of the Contains operator. In this case, the selectivity function is stat1.ODCIStatsSelectivity. It is called as follows:

   stat1.ODCIStatsSelectivity (
      ODCIPredInfo('HR', 'Contains_fn', NULL, 29),
      sel,
      ODCIArgDescList(
         ODCIArgDesc(ODCIConst.ArgLit,
                     NULL, NULL, NULL, NULL, NULL, NULL),
         ODCIArgDesc(ODCIConst.ArgLit,
                     NULL, NULL, NULL, NULL, NULL, NULL),
         ODCIArgDesc(ODCIConst.ArgCol, 'T', 'HR', '"RESUME"', NULL, NULL, NULL),
         ODCIArgDesc(ODCIConst.ArgLit,
                     NULL, NULL, NULL, NULL, NULL, NULL)),
         1,
         1,
         NULL,
         'ORACLE')
   

4. Suppose the selectivity function returns a selectivity of 3 (percent). When the domain index is being evaluated, then the optimizer calls the user-defined index cost function as follows:

   stat1.ODCIStatsIndexCost (   ODCIIndexInfo('HR', 'T_RESUME',      ODCIColInfoList(ODCIColInfo('HR', 'T', '"RESUME"', NULL, NULL, NULL, 0, 0, 0, 0)), NULL, 0, 0, 0, 0),      3,      cost,      NULL,      ODCIPredInfo('HR', 'Contains', NULL, 13),      ODCIArgDescList( ODCIArgDesc(ODCIConst.ArgLit,                                   NULL, NULL, NULL, NULL, NULL, NULL),                       ODCIArgDesc(ODCIConst.ArgLit,                                   NULL, NULL, NULL, NULL, NULL, NULL),                       ODCIArgDesc(ODCIConst.ArgLit,                                   NULL, NULL, NULL, NULL, NULL, NULL)),      1,      1,      'ORACLE')
   

5. Suppose that the optimizer decides not to use the domain index because it is too expensive. Then it calls the user-defined cost function for the functional implementation of the operator as follows:

   stat1.ODCIStatsFunctionCost (
      ODCIFuncInfo('HR', 'Contains_fn', NULL, 1),
      cost,
      ODCIArgDescList(  ODCIArgDesc(ODCIConst.ArgCol, 
                          'T', 'HR', '"RESUME"', NULL, NULL, NULL),
                        ODCIArgDesc(ODCIConst.ArgLit, 
                           NULL, NULL, NULL, NULL, NULL, NULL)),
      NULL,
      'ORACLE')
   

21.1.2 EXPLAIN PLAN

EXPLAIN PLAN shows the user-defined CPU and I/O costs for domain indexes in the CPU_COST and IO_COST columns of PLAN_TABLE. For example, suppose we have a table Emp_tab and a user-defined operator Contains. Further, suppose that there is a domain index EmpResume_indx on the Resume_col column of Emp_tab, and that the indextype of EmpResume_indx supports the operator Contains. Then, the query

SELECT * FROM Emp_tab WHERE Contains(Resume_col, 'Oracle') = 1

might have the following plan:

OPERATION	OPTIONS	OBJECT_NAME	CPU_COST	IO_COST
SELECT STATEMENT
TABLE ACCESS	BY ROWID	EMP_TAB
DOMAIN INDEX		EMPRESUME_INDX	300	4

21.1.3 INDEX Hint

The index hint applies to domain indexes. In other words, the index hint forces the optimizer to use the hinted index for a user-defined operator, if possible.

21.1.4 ORDERED_PREDICATES Hint

The hint ORDERED_PREDICATES forces the optimizer to preserve the order of predicate evaluation (except predicates used for index keys) as specified in the WHERE clause of a SQL DML statement.

21.2 User-Defined ODCIStats Functions

User-defined ODCIStats functions are used for table columns, functions, package, type, indextype or domain indexes.

Table 21-1 Summary of User-Defined ODCIStats Functions

Function	Description
ODCIGetInterfaces()	Discover which version of the ODCIStats interface the user has implemented.
ODCIStatsCollect()	Called by the DBMS_STATS package to collect user-defined statistics on a table, a partition of a table, an index, or a partition of an index.
ODCIStatsDelete()	Deletes user-defined statistics on a table, a partition of a table, an index, or a partition of an index.
ODCIStatsFunctionCost()	Computes the cost of a function.
ODCIStatsExchangePartition()	Exchanges domain index statistics when an ALTER TABLE EXCHANGE PARTITION ... INCLULDING INDEXES command is issued.
ODCIStatsIndexCost()	Calculates the cost of a domain index scan.
ODCIStatsSelectivity()	Specifies the selectivity of a predicate.
ODCIStatsTableFunction()	Provides cardinality statistics for table functions and input cursor expressions.
ODCIStatsUpdPartStatistics()	Updates statistics during partition maintenance operations. Patches the domain index statistics.

21.2.1 ODCIGetInterfaces()

ODCIGetInterfaces is invoked by the server to discover which version of the ODCIStats interface the user has implemented in the methods of the user-defined statistics type.

Syntax

FUNCTION ODCIGetInterfaces(
   ifclist OUT ODCIObjectList)
RETURN NUMBER;

Parameter	IN/OUT	Description
ifclist	OUT	The version of the ODCIStats interfaces implemented by the statistics type. This value should be SYS.ODCISTATS2.

Returns

ODCIConst.Success on success, ODCIConst.Error otherwise.

21.2.2 ODCIStatsCollect()

Called by the DBMS_STATS package to collect user-defined statistics.

Syntax	Description
FUNCTION ODCIStatsCollect(    col ODCIColInfo,    options ODCIStatsOptions,    statistics OUT RAW,    env ODCIEnv) return NUMBER;	Called by the DBMS_STATS package to collect user-defined statistics on a table or a partition of a table.
FUNCTION ODCIStatsCollect(    ia ODCIIndexInfo,    options ODCIStatsOptions,    statistics OUT RAW,    env ODCIEnv) return NUMBER;	Called to collect user-defined statistics on an index or a partition of an index.

Parameter	IN/OUT	Description
col		Column for which statistics are being collected
options		Options passed to DBMS_STATS
statistics		User-defined statistics collected
env		Contains general information about the environment in which the routine is executing
ia		Domain index for which statistics are being collected

Returns

The function returns ODCIConst.Success, ODCIConst.Error, or ODCIConst.Warning.

Usage Notes

• This function should be implemented as a STATIC type method.

• If statistics are being collected for only one partition, the TablePartition field in the ODCIColInfo type is filled in with the name of the partition. Otherwise (if statistics must be collected for all the partitions or for the entire table), the TablePartition field is null.

• If the DBMS_STATS package methods are executed to collect user-defined statistics on a partitioned table, then n+1 ODCIStatsCollect calls are made, where n is the number of partitions in the table. The first n calls are made with the TablePartition attribute in ODCIColInfo filled in with the partition name and the ODCIStatsOptions.CallProperty set to IntermediateCall. The last call is made with ODCIEnv.CallPropertyflag set to FinalCall to allow you to collect aggregate statistics for the entire table.

• If user-defined statistics are being collected for only one partition of the table, two ODCIStatsCollect calls are made. In the first, you should collect statistics for the partition. For this call, the TablePartition attribute of the ODCIColInfo structure is filled in and the ODCIEnv.CallProperty is set to FirstCall.

• In the second call you can update the aggregate statistics of the table based upon the new statistics collected for the partition. In this call, the ODCIEnv.CallPropertyflag is set to FinalCall to indicate that it is the second call. The ODCIColInfo.TablePartition is filled in with the partition name in both the calls.

• The ODCIStatsCollect() method is invoked only one time for a non-partitioned domain index, a partitioned domain index and a partition in a domain index. If the statistics are being collected only for one partition in a domain index, the IndexPartitionNum field in the ODCIIndexInfo type is filled in with the partition number. Otherwise, the IndexPartitionNum field is null.

• Because the statistics OUT RAW argument of statistics is not used in the new interface, the cartridge developer should store the user-defined statistics result in some user-defined tables.

• If a non-partitioned domain index is being ANALYZEd, the user should collect statistics for the domain index.

• If a partitioned domain index is being ANALYZEd,

  • ODCIEnv.CallProperty = StatsGlobalAndPartition means that the user should collect statistics for all partitions in the domain index and then aggregate statistics of the domain index based upon the statistics collected for all the partitions

  • ODCIEnv.CallProperty = StatsGlobal means that the user should aggregate domain index statistics from the statistics of all the domain index partitions.

  • ODCIEnv.CallProperty = StatsPartition means that the user should collect statistics for all index partitions in the domain index.

• If only one partition of the domain index is being ANALYZEd,

  • ODCIEnv.CallProperty = StatsGlobalAndPartition means that the user should collect statistics for the single index partition and then aggregate statistics of the domain index based upon the statistics of all the partitions.

  • ODCIEnv.CallProperty = StatsGlobal means that the user should aggregate domain index statistics from the statistics of all the index partitions.

  • ODCIEnv.CallProperty = StatsPartition means that the user should collect statistics for the single index partition.

• Note that when ODCIEnv.CallProperty = StatsGlobalAndPartition or StatsGlobal, the user should aggregate statistics for the domain index, depending on the availability of the statistics collected for the other index partitions. If the statistics for all the index partitions are available, aggregate these statistics. If any one statistics for an index partition is absent, do nothing.

21.2.3 ODCIStatsDelete()

ODCIStatsDelete is called to delete user-defined statistics.

Syntax	Description
FUNCTION ODCIStatsDelete(    col ODCIColInfo,    statistics OUT RAW,    env ODCIEnv) return NUMBER;	Deletes user-defined statistics on a table or a partition of a table.
FUNCTION ODCIStatsDelete(    ia ODCIIndexInfo,    statistics OUT RAW,    env ODCIEnv) return NUMBER;	Deletes user-defined statistics on an index or a partition of an index.

Parameter	IN/OUT	Description
col		Column for which statistics are being deleted
statistics	OUT	Contains table-level aggregate statistics for a partitioned table or index
env		Contains general information about the environment in which the routine is executing
ia		Domain index for which statistics are deleted

Returns

ODCIConst.Success, ODCIConst.Error, or ODCIConst.Warning.

Usage Notes

• This function should be implemented as a STATIC method.

• When the function is called for a non-partitioned table, the statistics argument in the ODCIStatsDelete interface is ignored.

• If the statistics are being deleted for a partitioned table, the ODCIStatsDelete is called n+1 times. The first n calls are with the partition name filled in the ODCIColInfo structure and the ODCIEnv.CallProperty set to IntermediateCall. The last call is made with the ODCIEnv.CallProperty set to FinalCall.

• In the first call, delete the statistics for the specific partitions; and in the last call drop or clean up any structures created for holding statistics for the deleted table. The ODCIColInfo.TablePartition is set to null in the last call. In the first call, the TablePartition field is filled in.

• If statistics are being deleted for only one partition and the _minimal_stats_aggregation parameter is set to FALSE, two ODCIStatsDelete calls are made. In each call, ODCIColInfo.TablePartition is filled in with the partition name. On the first call, delete any user-defined statistics collected for that partition. On the second call, update the aggregate statistics for the table.

• If statistics are being deleted for one partition and _minimal_stats_aggregation is set to TRUE, ODCIStatsDelete is only called one to delete any user-defined statistics collected for that partition.

• The initial value of _minimal_stats_aggregation is TRUE.

• The ODCIStatsDelete() method is invoked only one time for non-partitioned domain index, partitioned domain index, or an index partition.

• If the statistics is being deleted for a non-partitioned domain index, the user should delete user-defined statistics for the domain index.

• If the statistics is being deleted for a partitioned domain index, the user should delete the aggregated statistics of the domain index and optionally delete user-defined statistics for all domain index partitions, depending on Options in ODCIEnv.CallProperty:

  • ODCIEnv.CallProperty = StatsGlobalAndPartition means that the user should delete statistics for all the domain index partitions and aggregated statistics of the domain index.

  • ODCIEnv.CallProperty = StatsGlobal means that the user should delete the aggregated statistics of the domain index.

  • ODCIEnv.CallProperty = StatsPartition is not valid option.

• If the statistics is being deleted for only one partition of the index, the user should delete user-defined statistics for the index partition.

21.2.4 ODCIStatsFunctionCost()

Computes the cost of a function.

Syntax

FUNCTION ODCIStatsFunctionCost(
   func ODCIFuncInfo, 
   cost OUT ODCICost, 
   args ODCIArgDescList, 
   list,
   env ODCIEnv) 
return NUMBER;

Parameter	IN/OUT	Description
func		Function or type method for which the cost is being computed
cost	OUT	Computed cost (must be positive whole numbers)
args		Descriptor of actual arguments with which the function or type method was called. If the function has n arguments, the args array contains n elements, each describing the actual arguments of the function or type method
list		List of actual parameters to the function or type method; the number, position, and type of each argument must be identical in the function or type method.
env		Contains general information about the environment in which the routine is executing

Returns

ODCIConst.Success, ODCIConst.Error, or ODCIConst.Warning.

Usage Notes

This function should be implemented as a static type method.

21.2.5 ODCIStatsExchangePartition()

Exchanges domain index statistics when an ALTER TABLE EXCHANGE PARTITION ... INCLULDING INDEXES command is issued.

Syntax

FUNCTION ODCIStatsExchangePartition(
   ia ODCIIndexInfo, 
   ia1 ODCIIndexInfo,
   env ODCIEnv) 
return NUMBER;

Parameter	IN/OUT	Description
ia		Information about the index partition that must be exchanged
ia1		Information about the index of the non-partitioned table with which the partition is exchanged
env		Contains general information about the environment in which the routine is executing

Returns

ODCIConst.Success, ODCIConst.Error, or ODCIConst.Warning

Usage Notes

• This method should be implemented as a STATIC type.

• This method should be capable of converting the statistics associated with a domain index partition into statistics associated with a non-partitioned domain index, and the reverse. If the statistics are missing for one of the indexes or index partitions, the user should be able to delete these statistics.

21.2.6 ODCIStatsIndexCost()

Calculates the cost of a domain index scan, either a scan of the entire index or a scan of one or more index partitions if a local domain index has been built.

Syntax

FUNCTION ODCIStatsIndexCost(
   ia ODCIIndexInfo, 
   sel NUMBER, 
   cost OUT ODCICost, 
   qi ODCIQueryInfo, 
   pred ODCIPredInfo, 
   args ODCIArgDescList,
   start operator_return_type,
   stop operator_return_type,
   list, 
   env ODCIEnv) 
return NUMBER;

Parameter	IN/OUT	Description
ia		domain index for which statistics are being collected
sel		the user-computed selectivity of the predicate
cost		computed cost (must be positive whole numbers)
qi		Information about the query
pred		Information about the predicate
args		Descriptor of start, stop, and actual value arguments with which the operator was called. If the operator has n arguments, the args array contains n+1 elements, the first element describing the start value, the second element describing the stop value, and the remaining n-1 elements describing the actual value arguments of the operator (that is, the arguments after the first)
start		Lower bound of the operator (for example, 2 for a predicate fn(...) > 2)
stop		Upper bound of the operator (for example, 5 for a predicate fn(...) < 5)
list		List of actual parameters to the operator (excluding the first); the number, position, and type of each argument must be identical to the one in the operator.
env		Contains general information about the environment in which the routine is executing

Returns

ODCIConst.Success, ODCIConst.Error, or ODCIConst.Warning

Usage Notes

• For each table in the query, the optimizer uses partition pruning to determine the range of partitions that may be accessed. These partitions are called interesting partitions. The set of interesting partitions for a table is also the set of interesting partitions for all domain indexes on that table. The cost of a domain index can depend on the set of interesting partitions, so the optimizer passes a list of interesting index partitions to ODCIStatsIndexCost in the args argument (the type of this argument, ODCIArgDescList, is a list of ODCIArgDesc argument descriptor types) for those arguments that are columns. For non-partitioned domain indexes or for cases where no partition pruning is possible, no partition list is passed to ODCIStatsIndexCost, and you should assume that the entire index is accessed.

• The domain index key can contain multiple column arguments (for example, the indexed column and column arguments from other tables appearing earlier in a join order). For each column appearing in the index key, the args argument contains the list of interesting partitions for the table. For example, for an index key

  op(T1.c1, T2.c2) = 1
  

  the optimizer passes a list of interesting partitions for tables T1 and T2 if they are partitioned and there is partition pruning for them.

• This function should be implemented as a static type method.

• Only a single call is made to the ODCIStatsIndexCost() function for queries on partitioned or non-partitioned tables. For queries on partitioned tables, additional information is passed in the ODCIStatsIndexCost() function. Note that some partitions in the list passed to ODCIStatsIndexCost() may not actually be accessed by the query. The list of interesting partitions chiefly serves to exclude partitions that are definitely not accessed.

• When the ODCIStatsIndexCost() function is invoked, users can fill in a string in the IndexCostInfo field of the cost attribute to supply any additional information that might be helpful. The string (255 characters maximum) is displayed in the OPTIONS column in the EXPLAIN PLAN output when an execution plan chooses a domain index scan.

• Users implementing this function must return 'SYS.ODCISTATS2' in the ODCIGetInterfaces() call.

See Also:

• ODCIGetInterfaces()

• ODCIStatsIndexCost()

21.2.7 ODCIStatsSelectivity()

Specifies the selectivity of a predicate. The selectivity of a predicate involving columns from a single table is the fraction of rows of that table that satisfy the predicate. For predicates involving columns from multiple tables (for example, join predicates), the selectivity should be computed as a fraction of rows in the Cartesian product of those tables.

Syntax

FUNCTION ODCIStatsSelectivity(
   pred ODCIPredInfo, 
   sel OUT NUMBER, 
   args ODCIArgDescList, 
   start function_return_type, 
   stop function_return_type, 
   list, 
   env ODCIEnv) 
return NUMBER;

Parameter	IN/OUT	Description
pred		Predicate for which the selectivity is being computed
sel		The computed selectivity, expressed as a number between (and including) 0 and 100, represents a percentage. The optimizer ignores numbers less than 0 or greater than 100 as invalid values. If the computed selectivity is less than 0.5%, a value of 0 may be returned in the output parameter sel. A selectivity of 0 does not mean that the predicate will be removed
args		Descriptor of start, stop, and actual arguments with which the function, type method, or operator was called. If the function has n arguments, the args array contains n+2 elements, the first element describing the start value, the second element describing the stop value, and the remaining n elements describing the actual arguments of the function, method, or operator
start		Lower bound of the function (for example, 2 for a predicate fn(...) > 2)
stop		Upper bound of the function (for example, 5 for a predicate fn(...) < 5)
list		List of actual parameters to the function or type method; the number, position, and type of each argument must be identical to the one in the function, type method, or operator.
env		Contains general information about the environment in which the routine is executing

Returns

ODCIConst.Success, ODCIConst.Error, or ODCIConst.Warning

Usage Notes

• As in ODCIStatsIndexCost, the args argument contains a list of interesting partitions for the tables whose columns are referenced in the predicate for which the selectivity has to be computed. These interesting partitions are partitions that cannot be eliminated by partition pruning as possible candidates to be accessed. The set of interesting partitions is passed to the function only if partition pruning has occurred (in other words, the interesting partitions are a strict subset of all the partitions).

• For example, when ODCIStatsSelectivity is called to compute the selectivity of the predicate:

  f(T1.c1, T2.c2) > 4
  

  the optimizer passes the list of interesting partitions for the table T1 (in the argument descriptor for column T1.c1) if partition pruning is possible; similarly for the table T2.

  If a predicate contains columns from several tables, this information is indicated by the flag bit PredMultiTable, set in the Flags attribute of the pred argument.

• This function should be implemented as a static type method.

• Users implementing this interface must return 'SYS.ODCISTATS2' in the ODCIGetInterfaces call.

• The selectivity of a predicate involving columns from a single table is the fraction of rows of that table that satisfy the predicate. For predicates involving columns from multiple tables (for example, join predicates), the selectivity should be computed as a fraction of rows in the Cartesian product of those tables. For tables with partition pruning, the selectivity should be expressed relative to the cardinalities of the interesting partitions of the tables involved.

  The selectivity of predicates involving columns on partitioned tables is computed relative to the rows in the interesting partitions. Thus, the selectivity of the predicate

  g(T1.c1) < 5
  

  is the percentage of rows in the set of interesting partitions (or all partitions if no partition pruning is possible) that satisfies this predicate. For predicates with columns from multiple tables, the selectivity must be relative to the number of rows in the cartesian product of the tables.

• For example, consider the predicate:

  f(T1.c1, T2.c2) > 4
  

  Suppose that the number of rows in the interesting partitions is 1000 for T1 and 5000 for T2. The selectivity of this predicate must be expressed as the percentage of the 5,000,000 rows in the Cartesian product of T1 and T2 that satisfy the predicate.

• If a predicate contains columns from several tables, this information is indicated by the flag bit PredMultiTable set in the Flags attribute of the pred argument.

• A selectivity expressed relative to the base cardinalities of the tables involved may be only an approximation of the true selectivity if cardinalities (and other statistics) of the tables have been reduced based on single-table predicates or other joins earlier in the join order. However, this approximation to the true selectivity should be acceptable to most applications.

• Only one call is made to the ODCIStatsSelectivity function for queries on partitioned or non-partitioned tables. In the case of queries on partitioned tables, additional information is passed while calling the ODCIStatsSelectivity function.

21.2.8 ODCIStatsTableFunction()

This function provides cardinality statistics for table functions and input cursor expressions.

Syntax

STATIC FUNCTION ODCIStatsTableFunction(
   func IN SYS.ODCIFuncInfo, 
   outStats OUT SYS.ODCITabFuncStats, 
   argDesc IN SYS.ODCIArgDescList, 
   list)
RETURN NUMBER;

Parameter	IN/OUT	Description
func		Table function name
outStats		Number of rows expected to be returned
argDesc		Description of the arguments to the table function
list		The arguments' compile-time values. Expressions that only have values at run time are represented by nulls.

Returns

ODCIConst.Success, ODCIConst.Error, or ODCIConst.Warning.

21.2.9 ODCIStatsUpdPartStatistics()

Updates statistics during partition maintenance operations. This lets the statistics type patch up the domain index statistics to correctly reflect the partition maintenance operation.

Syntax

STATIC FUNCTION ODCIStatsCollect(
   ia ODCIIndexInfo,
   palist ODCIPartInfoList,
   env ODCIEnv) 
RETURN NUMBER

Parameter	IN/OUT	Description
ia		Contains information about the domain index. It does not contain any partition specific information
palist		Contains information about the partitions that are to be dropped or added
env		Environment handle passed to the routine

Returns

ODCIConst.Success, ODCIConst.Error, or ODCIConst.Warning.

• When the statistics type is specified by the SYSTEM MANAGED approach, then the ODCIStatsUpdPartStatistics() method is invoked only one time during PMO. Only DML and query are allowed in the method implementation.

• If the user maintains the domain index statistics in a global non-partitioned table, then the user should delete the entry for the user-defined statistics for the dropped partition (and optionally add a NULL entry for added partition). They can then check if ODCIEnv.CallProperty is StatsGlobalAndPartition or StatsPartition. If ODCIEnv.CallProperty is StatsGlobalAndPartition then they should aggregate all the available index partition statistics. If ODCIEnv.CallProperty is StatsPartition they can simply delete the aggregate statistics, or leave the aggregate statistics as they are. ODCIEnv.CallProperty cannot be StatsGlobal for this call.

• The user should use the information passed in by the ODCIEnv.CallProperty to determine the type of statistics to delete and adjust.

• If the method returns ODCIConst.Error, the error is ignored and the partition management operation continues.