‎2008 Aug 15 5:58 PM
Hai Friends,
When we have to create an index?. How it is uefull?.
Kindly give me a detail explanation.
‎2008 Aug 16 12:35 PM
Hi T Vennila,
Need to create Secondary index depends on many circumstances...
Assume that u r fetching data from a DDIC table which contains huge data (records) and Primary key is not suffecient to get the data in timely manner... as it's taking a long time to execute u can create a secondary index for that table based on fields in where condition of ur select query... But it's not good to create secondary index without any such a need... it can make the performance worst if u create a secondary index on wrong fields and wrong tables... So take a lot care before creating secondary index...
Primary index : Its the index which is automatically created for the PRIMARY KEY FIELD(S) of the table.
The primary index is always created automatically in the R/3 System. It consists of the primary key fields of the database table. This means that for each combination of fields in the index, there is a maximum of one line in the table. This kind of index is also known as UNIQUE.
Secondary index : Its created as and when required,
based upon other field(s) of the table,
on which search criteria is used in sqls.
Secondary indexes should contain columns that you use frequently in a selection, and that are as highly selective as possible. The fewer table entries that can be selected by a certain column, the higher that columns selectivity. Place the most selective fields at the beginning of the index. Your secondary index should be so selective that each index entry corresponds to at most five percent of the table entries. If this is not the case, it is not worth creating the index. You should also avoid creating indexes for fields that are not always filled, where their value is initial for most entries in the table.
CREATION
go to SE11
enter table name
press display
from menu GOTO-> indexes
press create button
enter the fields for which you need the index
save and activate
use those fields in the Where condition of the select statement and see
Also have a look on below threads
Also request you to put ur Question in appropriate Forums so that u will also get good and Quick answer and it will be maintained in a good manner...
Hope it will solve your problem..
Thanks & Regards
ilesh 24x7
‎2008 Aug 16 12:08 PM
Hi,
Creating an Index in the DDIC ? If yes, i suggest you to post it in related forum.
Anyways, you would find a button for Indexes in Table definition.
Regards,
Wajid Hussain P.
‎2008 Aug 16 12:35 PM
Hi T Vennila,
Need to create Secondary index depends on many circumstances...
Assume that u r fetching data from a DDIC table which contains huge data (records) and Primary key is not suffecient to get the data in timely manner... as it's taking a long time to execute u can create a secondary index for that table based on fields in where condition of ur select query... But it's not good to create secondary index without any such a need... it can make the performance worst if u create a secondary index on wrong fields and wrong tables... So take a lot care before creating secondary index...
Primary index : Its the index which is automatically created for the PRIMARY KEY FIELD(S) of the table.
The primary index is always created automatically in the R/3 System. It consists of the primary key fields of the database table. This means that for each combination of fields in the index, there is a maximum of one line in the table. This kind of index is also known as UNIQUE.
Secondary index : Its created as and when required,
based upon other field(s) of the table,
on which search criteria is used in sqls.
Secondary indexes should contain columns that you use frequently in a selection, and that are as highly selective as possible. The fewer table entries that can be selected by a certain column, the higher that columns selectivity. Place the most selective fields at the beginning of the index. Your secondary index should be so selective that each index entry corresponds to at most five percent of the table entries. If this is not the case, it is not worth creating the index. You should also avoid creating indexes for fields that are not always filled, where their value is initial for most entries in the table.
CREATION
go to SE11
enter table name
press display
from menu GOTO-> indexes
press create button
enter the fields for which you need the index
save and activate
use those fields in the Where condition of the select statement and see
Also have a look on below threads
Also request you to put ur Question in appropriate Forums so that u will also get good and Quick answer and it will be maintained in a good manner...
Hope it will solve your problem..
Thanks & Regards
ilesh 24x7