Level Extreme platform
Subscription
Corporate profile
Products & Services
Support
Legal
Français
Which SQL Select would be faster?
Message
 
General information
Forum:
Visual FoxPro
Category:
Databases,Tables, Views, Indexing and SQL syntax
Environment versions
Visual FoxPro:
VFP 9 SP1
Miscellaneous
Thread ID:
01095983
Message ID:
01096103
Views:
18
This message has been marked as a message which has helped to the initial question of the thread.
>>Here's one more for you
>>
>>select * FROM PARENT p
>>	JOIN (SELECT distinct PK_FLD FROM CHILD WHERE(&cChildFilter)) dt1
>>		ON dt1.PK_fld = p.PK_fld
>>
>>
>
>I think I see where your approach is better. In your SQL Select, VFP has to "query" CHILD table only once. In my approach, SQL Select has to "jump" from quering PARENT to CHILD and back.

Hi Dmitry,

In VFP the queries with JOIN usualy faster than with correlated EXISTS subqueries. The opopsite is true for MS SQL Server.
--sb--
Previous
Next
Reply
Map
View

Click here to load this message in the networking platform