Level Extreme platform
Subscription
Corporate profile
Products & Services
Support
Legal
Français
Selecting records from two different tables in one query
Message
From
15/03/2010 14:40:09
 
 
To
15/03/2010 14:15:30
Cetin Basoz
Engineerica Inc.
Izmir, Turkey
General information
Forum:
Visual FoxPro
Category:
Databases,Tables, Views, Indexing and SQL syntax
Miscellaneous
Thread ID:
01454516
Message ID:
01454627
Views:
51
>>>>I'll try later - busy with work right now. I tried on the tables I had in my test database (in SQL Server).
>>>
>>>Ok I just tried for you:
>>>
>>                                                    t6   t5   t4   t3   t2   t1
>>>Client processing time         0    0    0    0    0   16 
>>>Total execution time        2328 2296 3046 2250 2328 5937 
>>>Wait time on server replies 2328 2296 3046 2250 2328 5921 
>>>
>>>
>>>Two passes. t1,4 (LEFT), t2,5 (NOT IN), t3, 6 (Exists).
>>>Cetin
>>
>>In your tests performance of the LEFT JOIN seems to be much worse than others. What are tables metrics and how many records did you get as a result of a query? Also, did you discharge the results or not?
>
>Yes as I told you before it was the slowest. Metric is simple. 2 million records table created, and copied onto another (structure was as simple as it can be, an ID plus a varchar data field. With a more complex structure it is likely it would be much slower). Then a few more records are added to one of them. Index created on join field.
>Cetin


I have a feeling this thread just went over my head
Previous
Next
Reply
Map
View

Click here to load this message in the networking platform