Solution : https://service.sap.com/sap/support/notes/444287 (SAP Service marketplace login required)
Summary :
SAP Note addresses an issue of poor performance despite correct index use due to placeholders in index trees after deletion. When data records are deleted, space in the index is not reclaimed but reserved by a placeholder until a new insertion utilizes it. This can lead to larger numbers of disk blocks being read during queries, degrading performance. To improve index storage quality, analysis can be performed using SAP R/3 transaction db02 or via Oracle SQL commands. The analysis provides essential insights into space utilization and placeholder proportions, recommending reorganization if specific thresholds, such as storage quality below 70% or excessive block wastage, are exceeded.
Key words :
checked -> 'detail analysis' button -> menu analyze index -storage qualitya percentage, checked -> 'detail analysis' button -> menu analyze index - validate structure, transaction db02 -> 'detail analysis' button -> enter table, sqlplus sapr3/<passwd>create table index_storage, -> 'table <-> indices ' button -> click index, sqlplus sapr3/<passwd>set heading, sql> analyze index sapr3, -tree leaf blocks entries deleted, sysdba'sql> connect internal, analyze index command
Related Notes :
| 806554 | FAQ: I/O-intensive database operations |
| 771929 | FAQ: Index fragmentation |
| 23278 | MD01, MDBT: Performance during MRP run |