Regarding index table

[Former Member]

Tables with indexes , result in reduced performance in what kind of OPEN SQL statment

thanks in advance

Rishi

[Former Member]

Hi,

if you create indexes on a particular set of fields in a table and use another set of fields in the where clause in a SELECT statement on that table, it may result in a reduced performance.

Reward points if found useful...!

Cheers

Abhishek

[Former Member]

insert

update

delete

all the the 3 open sql commands.

because it has to adjust everytime you do any manipulation of database table.

regds,

kiran

[Former Member]

Hi,

Table with indexes helps in retreiving data from the table using SQL statements.

However the problem with the performance lies when we update/modify or insert to the DB table as that will also look for the index while updating that and hence will take more time for this.

Regards

Deepu

[former_member188827]

The order of the fields in the index is very important for the accessing speed. The first fields should be those which have constant values for a large number of selections. During selection, an index is only of use up to the first unspecified field.

Only those fields that significantly restrict the set of results in a selection make sense for an index.

SELECT * FROM ADRTAB WHERE TITEL = ‘Prof.’ AND NAME = X AND VORNAME = Y.

The field TITLE would rarely restrict the records specified with NAME and FIRSTNAME in an index on NAME, FIRSTNAME and TITLE, since there are probably not many people with the same name and different titles. This would not make much sense in this index. An index on field TITLE alone would make sense for example if all professors are frequently selected.

Additional indexes can also place a load on the system since they must be adjusted each time the table contents change. Each additional index therefore slows down the insertion of records in the table.

For this reason, tables in which entries are very frequently written generally should only have a few indexes.

The database system sometimes does not use a suitable index for a selection, even if there is one. The index used depends on the optimizer used for the database system. You should therefore check if the index you created is also used for the selection

hope it helps!.

rgds.