alter query

bikkaran

hi ,

i have some simple doubt in DB2
1. can we disable or enable an INDEX.
2. can we drop a column from a table .
3. can we change the datatype of a column i.e say from varchar to
integer

Please help me update my knowledge.

thanks
bikash

Mar 24 '06 #1

Knut Stolze

bi******@in.ibm.com wrote:

hi ,

i have some simple doubt in DB2
1. can we disable or enable an INDEX.
What do you have in mind with disable/enable? Should the index not be used
during queries or not being maintained during DML statements?
2. can we drop a column from a table .
Not yet. But the Control Center provides a way to do that.
3. can we change the datatype of a column i.e say from varchar to
integer

No.

--
Knut Stolze
DB2 Information Integration Development
IBM Germany

Mar 24 '06 #2

Serge Rielau

bi******@in.ibm.com wrote:

hi ,

i have some simple doubt in DB2
1. can we disable or enable an INDEX. DROP INDEX.... 2. can we drop a column from a table . In DB2 V8 for zOS yes. In DB2 for LUW this will be supported in Viper,
today (V8.2) there is GUI driven support in the control center. 3. can we change the datatype of a column i.e say from varchar to
integer

In DB2 for LUW you can INCREASE the length of a VARCHAR column.
In Viper you will be able to do any alter which cannot cause loss of data.
VARCHAR->INTEGER: No
INTEGER->VARCHAR: I think yes in Viper.

Cheers
Serge

--
Serge Rielau
DB2 Solutions Development
IBM Toronto Lab

Mar 24 '06 #3

Bob [IBM]

Serge Rielau wrote:

bi******@in.ibm.com wrote:

hi ,

i have some simple doubt in DB2
1. can we disable or enable an INDEX.

DROP INDEX....

2. can we drop a column from a table .

In DB2 V8 for zOS yes. In DB2 for LUW this will be supported in Viper,
today (V8.2) there is GUI driven support in the control center.

3. can we change the datatype of a column i.e say from varchar to
integer

In DB2 for LUW you can INCREASE the length of a VARCHAR column.
In Viper you will be able to do any alter which cannot cause loss of
data.
VARCHAR->INTEGER: No
INTEGER->VARCHAR: I think yes in Viper.

Cheers
Serge

Just be careful on the GUI driven option as I believe the underlying
task is to drop and recreate the table?

Bob

Mar 26 '06 #4