Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

The following table describes the different index change parameters.

Table 9- 1 Index change parameters

ParameterDescription
EvaluateCheck box to select the table row for manipulation.
RemoveButton to remove its table row from the Index list.
EditButton to edit the table row.
ActionIndicates the type of the change, which can be one of the following: Index Creation, Index Modifications, Index Deletion, Gather Statistics, Accept SQL Profile, or Rewrite Query.
OwnerOracle owner.
TableName of the table that the index belongs to.
ObjectRecommended Object name.
DDL/CommentDDL command for recommendation implementation or comment regarding the recommendation.
ColumnsList of columns in the index.
TypeNormal (B*Tree) or Bitmap.
UniqueIndicates whether the index is unique or not.
Leaf BlocksAnalysis of statistics information. This column is blank until you click Evaluate. If an index is deleted, this column will show N/A.
Distinct KeysAnalysis of statistics information. This column is blank until you click Evaluate. If an index is deleted, this column will show N/A.
Clustering FactorAnalysis of statistics information. This column is blank until you click Evaluate. If an index is deleted, this column will show N/A.
PartitionedIndicates whether the index is partitioned or not.

About the Summary area

The Summary area in the What-If tab displays whether or not a statement, J2EE Caller Service, or Web Transaction would be effected by the change after clicking Evaluate, as follows:

...

Depending upon whether or not a statement was evaluated, you can launch to either the Plan tab or the Compare tab in the SQL tab. The following icons indicate to which tab in the SQL tab a statement will be launched, in context:

Table 9- 2 Icons to launch in context

IconDescription
Image Modified
If the statement was evaluated, launches the SQL tab on the Plan tab.
Image Modified
Launches the SQL tab on the Compare tab so that you can compare the explain plan for this version with the original.

Evaluating index changes

The buttons below the Main area let you add and simulate an index change. The icons on the table rove let you edit index changes for evaluation or delete a suggested change from the evaluation table.

...

The following tables describe the columns in the tables:

Table 9- 3 Columns for J2EE Caller Service and Web Transaction table

ColumnDescription
J2EE Caller Service or Web TransactionNames of either the J2EE Caller Services or Web Transactions.
In OracleResource consumption of the impacted J2EE Caller Service or Web Transaction during the selected time frame. The format is: hh:mm:ss. Use this column to assess the heavy resource consuming statements that are either positively or negatively impacted.
Gain (%)The amount in gain in percentage when performing the suggested index change.
Statement ExecutionsThe amount of statement executions.
Affected TransactionThe number of transactions for the specific J2EE Caller Service that are affected by the index change (for J2EE Caller Services only).

Table 9- 4 Columns for the Statement table

ColumnDescription
Image Modified
Lets you launch to the SQL tab on the plan tab, if the statement was not evaluated, or the SQL tab on Compare tab, to compare the explain plan for this version of the statement with the original. See “About launching to SQL tab in context” on page 161.
TextPortion of the SQL text.
In OracleResource consumption of the impacted statement during the selected time frame. The format is: hh:mm:ss. Use this column to assess the heavy resource consuming statements that are either positively or negatively impacted.
CostCurrent estimated cost of the Oracle Optimizer, as taken from the latest explain plan.
Predicted CostPredicted cost of the Oracle Optimizer for the new plan.
Gain (%)The amount in gain in percentage when performing the suggested index change.
ExecutionsNumber of times the statement was executed during the selected time frame.
StatementName of the impacted statement.
Statement IDThe ID of the statement.
statement-usernameThe user name which executed the statement.
statement-explain-typeDisplay the explain type used for the recommendations.
CommentPrecise for Oracle may include its own comment on the simulated change, or why, for example, costs are not available.
Affected TransactionThe number of transactions for the specific statement that are affected by the index change.

Anchor
HowtheWhatIftabcanhelpyouidentifyperformanceenhancements
HowtheWhatIftabcanhelpyouidentifyperformanceenhancements
How the What-If tab can help you identify performance enhancements

...

Further information can be gathered from the change ratio, which varies from 113%—only slightly worse—to up to 700%. It is therefore unlikely that we implement the proposed change.

 

Precise. Performance intelligence from click to storage. Learn more > >

...