![]() Transaction code – ST05 (performance trace tool).Is intended for fine-tuning individual transactions, programs, and function modules.Allows you to examine the performance of any transaction, ABAP program, or function module that you create in the ABAP workbench.The system checks the entire program and allows you to run additional checks with a greater scope than the normal syntax check.Choose program - > check -> extended program check.Creating indexes should be done carefully and jointly with the SAP database administrator.Validate the use of table indexes by performing a SQL trace The most suitable index for the select criteria might not be the index chosen for use by the database optimizer.The creation of an index can affect performance adversely.Remove unused indexes or ones that change due to report design changes.In general, frequently updated tables should have only few indexes while frequently selected tables might have more These tradeoffs must be weighed against one another. On the other hand, the indexes increase the efficiency of reads. Updates are only slowed down if indexed fields are updated. Each index slows down the inserts into the table.Be sure to order the columns in the WHERE clause of a SELECT in the same order as an index table.Use all fields in the WHERE clause in the same order for an index, as skipping one field disables the index When selecting data from a table, look at the structure of all of the available indexes and tailor the WHERE clause to take advantage of the most selective index.Multiple indexes of one table should be disjoint (have few common fields), in order not to confuse the optimizer which index to use.Some optimizers are able to combine two or more indexes to execute a query. Place columns toward the end of the index if they are either infrequently used in SELECTS or are part of reporting SELECTS that involve ranges of values. ![]() For example, if a SELECT statement is written to include columns 1 and 2 with “equal to” expressions in the where clause and column 3 and 4 are selected with value ranges, then the index should be created with columns in the sequence of 1, 2, 3, 4. Rearrange columns of an index to match the selection criteria. The most “common” columns are those where reports are selecting columns with no ranges - the WHERE clause for these columns is an “equal to” expression. Place the most “common” columns at the beginning of an index.As indexes are adjusted each time table contents are changed, create secondary indexes discerningly to minimize the impact on the system.Only include fields in an index if they reduce the selected data significantly.Indexes may be developed when the required access to a database table is based on fields other than the primary key of the table. ![]()
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