Level Extreme platform
Subscription
Corporate profile
Products & Services
Support
Legal
Français
Optimizing speed of SQL Select
Message
 
General information
Forum:
Visual FoxPro
Category:
Other
Environment versions
Visual FoxPro:
VFP 6 SP5
Miscellaneous
Thread ID:
01057215
Message ID:
01057231
Views:
8
David,

The indexes are on each field. That is, I have many index tags, each one on one field. The SYS(3054) says "Rushmore optimization level is Full". Yes, I do have index tag on deleted(). And SET DELETE is ON.

>Dmitry,
>
>What are the exact index expression(s)? What does sys(3054,11) display? Is SET DELETED ON? Do you have an index on deleted()?
>
>>I am trying to improve a speed of a SQL query. Currently the query looks like this:
>>
>>
>>select MYFIELD from MYTABLE where MYFIELD1 = "00"
>>
>>
>>Note that the table has index tag on field MYFIELD1.
>>The customer says that working against a table of about 150,000 record this takes up to 5 minutes.
>>
>>I want to add two more conditions to the query, both on fields that have index tags. Therefore the query will look like following:
>>
>>
>>select MYFIELD from MYTABLE where MYFIELD1 = "00" and MYFIELD2 = "O"
>>and MYFIELD3 = "C"
>>
>>
>>I know that the table has much fewer records on the MYFIELD2 = "O" and then within those there are some small number where MYFIEL3 = "C", and then within those there are some that have MYFIELD1 = "00".
>>
>>My question is, does it matter in which order I will put the WHERE expression in the above SQL Select?
"The creative process is nothing but a series of crises." Isaac Bashevis Singer
"My experience is that as soon as people are old enough to know better, they don't know anything at all." Oscar Wilde
"If a nation values anything more than freedom, it will lose its freedom; and the irony of it is that if it is comfort or money that it values more, it will lose that too." W.Somerset Maugham
Previous
Next
Reply
Map
View

Click here to load this message in the networking platform