What are some characteristics of columns that benefit from indexes ?
Primary key and foreign key columns; columns that have unique values; columns that have aggregates computed frequently and columns used to test the existence of a value.
If you liked this question/asnwer, make sure you
Subscribe to KyaPoocha.com RSS feed!
BOOKMARK THIS : BlinkList | del.icio.us | Digg it | Furl | reddit | StumbleUpon | Yahoo MyWeb |
Related Interview Questions
What type of Indexing mechanism do we need to use for a typical datawarehouse ? 23.09.08
On the fact table it is best to use bitmap indexes. Dimension tables can use bitmap and/or the other types of clustered/non-clustered, unique/non-unique indexes...How do you select a row using indexes ? 26.07.08
Specify the indexed columns in the WHERE clause....After a table is defined, can columns be removed ? 25.07.08
The only way to remove columns from an existing table involves a migration program that extracts only the desired columns of data, redefining the table without...After a table is defined, can columns be removed ? 14.07.08
The only way to remove columns from an existing table involves a migration program that extracts only the desired columns of data, redefining the table without...How many types of columns are there and what are they? 21.05.08
Formula columns : For doing mathematical calculations and returning one value Summary Columns : For doing summary calculations such as summations etc. Place h...What does the RUNSTATS Utility do? 09.04.08
The RUNSTATS Utility collects statistical information for DB2 table spaces, partitions, indexes, tables and columns and stores this data in the DB2 Catalog....What is a composite index and how does it differ from a multiple index ? 01.04.08
A multiple index is not one index but two indexes for two different columns of a table. A composite index is one index made up of combined values from two col...Lot of updates have been done on a table due to which indexes have gone haywire. What do you do ? 17.03.08
Looks like index page split has occurred. DO a REORG of the indexes....What are indexes? 12.03.06
Indexes are described as a copy of a database table reduced to specific fields. This data exists in sorted form. This sorting form ease fast access to the field...What is the use of INDEXES option in EXP command ? 12.03.06
A flag to indicate whether indexes on tables will be exported....