Hierarchy
SAP_BASIS (Software Component) SAP Basis Component⤷
BC-DB-DB4 (Application Component) DB2 for AS/400⤷
STU4 (Package) CCMS / AS/400
Basic Data
| Data Element | QQIDXA |
| Short Description | iSeries: Optimizer Advised Index (Database Monitor) |
Data Type
| Category of Dictionary Type | D | Domain |
| Type of Object Referenced | No Information | |
| Domain / Name of Reference Type | QQYN | |
| Data Type | CHAR | Character String |
| Length | 1 | |
| Decimal Places | 0 | |
| Output Length | 1 | |
| Value Table |
Further Characteristics
| Search Help: Name | ||
| Search Help: Parameters | ||
| Parameter ID | ||
| Default Component name | ||
| Change document | ||
| No Input History | ||
| Basic direction is set to LTR | ||
| No BIDI Filtering |
Field Label
| Length | Field Label | |
| Short | 11 | Index Adv. |
| Medium | 21 | Index Advised |
| Long | 41 | Index Advised |
| Heading | 55 | Index Advised |
Documentation
Definition
QQIDXA indicates whether the optimizer advises the creation of a permanent index to improve the performance of the execution of a statement.
If a permanent index might be beneficial, the key fields of the suggested index are listed in QQIDXD for the file-based database monitor or QIDXD for the memory-resident database monitor.
Note
For the file-based database monitor (STRDBMON/ENDDBMON), QQIDXA is only available for records with QQRID 3000, 3001 and 3002.
For the memory-resident database monitor QQIDXA is only available in the detail information tables SQ3000_DB4, SQ3001_DB4, SQ3002_DB4.
The optimizer can advise the creation of a permanent index, even though a table scan was performed or an existing index was used, because the estimated cost of creating a temporary index was higher.
Example
For the file-based database monitor started for the SAP System the native SQL statement
select a.qqtln, a.qqtfn, a.qqidxa, b.qqsttx
from lib_name/qqq3000 a, lib_name/qqq1000 b
where a.qqjfld = b.qqjfld
and a.qqucnt = b.qqucnt
and a.qqidxa = 'Y'
lists all queries where the opitmizer chose to perform a table scan and advised the creation of a permanent index.
(lib_name is the library name of the SAP System)
History
| Last changed by/on | SAP | 20070813 |
| SAP Release Created in |
