ROWID

[ibmlearner]

HI ALL..

WHAT IS ACTUALLY ROWID.

ITS FOR INDENTFYING THE ROW,MEANS THEN

WHAT IS THE USE OF INDEXES ???????

IS (UNIQUE) INDEX USES ROWID???

TIA.
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Thanks & Regards
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Learner

[Veera]

ROWID is a data type to store a unique Row IDentifier assigned by DB2.

Indexes are used to identify a unique tuple.( I mean entire columns of the record)

What do you mean by INDENTFYING THE ROW ??

Identifying by just the numbering of it ???

Or

Identifying by some value you provide to Table ??

First thing is possible by ROWID but not the second.

ROWID cant be used to identify the rows for a specific criteria , i mean its just the numbering for the rows which DB2 subsytem internally stores as a hidden column i guess

Normally we will provide some value in the where clause to fetch data
from DB2 in that case Indexes are in effect.

Select sal
From Emp
where sal = 100$ -> Here fetcing the data using a specif criteria like
where sal should be 100 cant be obtained by ROWID,

but your other query where you just want to fetch
the records from DB2 without any refernce to the
where clause specific condition like records
from 200 to 300 or so the ROWID can be used.

Thanks
Veera