Regarding ALV Tuning

Question

I want to create an ALV report to display the Purchase Order Details, the data will  come from 4 Database tables,I am extracting the data in 4 internal tables and then clubbing them to one final internal table,but the performance of my program is very bad,please suggest me some way.

Answer 1

hi,
first avoid occurs o etc.
delcare internal tables using types for structure and data with header line.
check for sy-subrc =0. for select statements ,use delete adjacent duplicates.
if there is large amount of data ise LIST display instead of grid.
for further performance issues chaeck below links.
BAP performance depends upon various factors and in devicded in three parts:
1. Database
2. ABAP
3. System
Run Any program using SE30 (performance analys) to improve performance refer to tips and trics section of SE30, Always remember that ABAP perfirmance is improved when there is least load on Database.
u can get an interactive grap in SE30 regarding this with a file.
also if u find runtime of parts of codes then use :
Switch on RTA Dynamically within ABAP Code
*To turn runtim analysis on within ABAP code insert the following code
SET RUN TIME ANALYZER ON.
*To turn runtim analysis off within ABAP code insert the following code
SET RUN TIME ANALYZER OFF.
Always check the driver internal tables is not empty, while using FOR ALL ENTRIES
Avoid for all entries in JOINS
Try to avoid joins and use FOR ALL ENTRIES.
Try to restrict the joins to 1 level only ie only for tables
Avoid using Select *.
Avoid having multiple Selects from the same table in the same object.
Try to minimize the number of variables to save memory.
The sequence of fields in 'where clause' must be as per primary/secondary index ( if any)
Avoid creation of index as far as possible
Avoid operators like <>, > , < & like % in where clause conditions
Avoid select/select single statements in loops.
Try to use 'binary search' in READ internal table. Ensure table is sorted before using BINARY SEARCH.
Avoid using aggregate functions (SUM, MAX etc) in selects ( GROUP BY , HAVING,)
Avoid using ORDER BY in selects
Avoid Nested Selects
Avoid Nested Loops of Internal Tables
Try to use FIELD SYMBOLS.
Try to avoid into Corresponding Fields of
Avoid using Select Distinct, Use DELETE ADJACENT
Go through the following Document
Check the following Links
Re: performance tuning
Re: Performance tuning of program
http://www.sapgenie.com/abap/performance.htm
http://www.thespot4sap.com/Articles/SAPABAPPerformanceTuning_PerformanceAnalysisTools.asp
check the below link
http://www.sap-img.com/abap/performance-tuning-for-data-selection-statement.htm
See the following link if it's any help:
http://www.thespot4sap.com/Articles/SAPABAPPerformanceTuning_PerformanceAnalysisTools.asp
Check also http://service.sap.com/performance
and
books like
http://www.sap-press.com/product.cfm?account=&product=H951
http://www.sap-press.com/product.cfm?account=&product=H973
http://www.sap-img.com/abap/more-than-100-abap-interview-faqs.htm
http://www.thespot4sap.com/Articles/SAPABAPPerformanceTuning_PerformanceAnalysisTools.asp
Performance tuning for Data Selection Statement
http://www.sap-img.com/abap/performance-tuning-for-data-selection-statement.htm
Run Time Analyser
http://help.sap.com/saphelp_47x200/helpdata/en/c6/617cafe68c11d2b2ab080009b43351/content.htm
SQL trace
http://help.sap.com/saphelp_47x200/helpdata/en/d1/801f7c454211d189710000e8322d00/content.htm
CATT - Computer Aided Testing Too
http://help.sap.com/saphelp_47x200/helpdata/en/b3/410b37233f7c6fe10000009b38f936/frameset.htm
Test Workbench
http://help.sap.com/saphelp_47x200/helpdata/en/a8/157235d0fa8742e10000009b38f889/frameset.htm
Coverage Analyser
http://help.sap.com/saphelp_47x200/helpdata/en/c7/af9a79061a11d4b3d4080009b43351/content.htm
Runtime Monitor
http://help.sap.com/saphelp_47x200/helpdata/en/b5/fa121cc15911d5993d00508b6b8b11/content.htm
Memory Inspector
http://help.sap.com/saphelp_47x200/helpdata/en/a2/e5fc84cc87964cb2c29f584152d74e/content.htm
ECATT - Extended Computer Aided testing tool.
http://help.sap.com/saphelp_47x200/helpdata/en/20/e81c3b84e65e7be10000000a11402f/frameset.htm
Just refer to these links...
performance
Performance
Performance Guide
performance issues...
Performance Tuning
Performance issues
performance tuning
performance tuning