Please start any new threads on our new
site at https://forums.sqlteam.com. We've got lots of great SQL Server
experts to answer whatever question you can come up with.
| Author |
Topic |
|
raj.prabhu001
Starting Member
16 Posts |
 Posted - 2011-11-23 : 02:29:49
|
| I want to select name from table where name like raj1) Select name From table Where name like 'raj%'2) Select name From table Where name like '%raj'1)Out of the two queries which one would retrieve data faster and why ?2)and how to make the slower query faster? |
|
|
visakh16
Very Important crosS Applying yaK Herder
52326 Posts |
Posted - 2011-11-23 : 03:05:58
|
| i think 1 will definitely retrieve data faster as there's more likely that it would go for index seek if one present in column. In second case, at max it will go for index scan as it starts with wildcard------------------------------------------------------------------------------------------------------SQL Server MVPhttp://visakhm.blogspot.com/ |
 |
|
|
Lamprey
Master Smack Fu Yak Hacker
4614 Posts |
Posted - 2011-11-23 : 10:35:39
|
| Depends.How many rows are in the table?How many rows does 'raj%' versus '%raj' return?Is there an index on Name?Does the table have a primary key?If the table has a primary key is it clustered or is there another index that is clustered?One way to speed up preceeding wildcard searches ('%something') is to created a persisted computed column with the text reversed, in this case REVERSE(Name). Then you can index that and use LIKE 'gnihtemos%' which gives you the possibility of an index seek. |
|
|
|
|
|
|
Query Optimization - Faster data retrival