Plateforme Level Extreme
Abonnement
Profil corporatif
Produits & Services
Support
Légal
English
Why is Optimization 'Partial'
Message
De
02/10/1997 16:00:16
 
 
À
02/10/1997 15:51:09
Larry Long
ProgRes (Programming Resources)
Georgie, États-Unis
Information générale
Forum:
Visual FoxPro
Catégorie:
Problèmes
Divers
Thread ID:
00052442
Message ID:
00052934
Vues:
36
>>>>>I am trying to determine why my SQL statement is returning
>>>>>'Partial' Optimization instead of full.
>>>>>
>>>>>SELECT Acctnum, DeptNum;
>>>>> FROM Chg;
>>>>> WHERE Chg.Acctnum='5555555';
>>>>> INTO CURSOR cResult
>>>>>
>>>>>Chg is 2+ Million Records
>>>>>There is an Index 'Acctnum' in Table Chg (Not Primary).
>>>>>Acctnum is C 7
>>>>>
>>>>>SYS(3054) Returns
>>>>> 'Using index tag acctnum to rushmore optimize table chg'
>>>>> 'Rushmore optimization level for tabl chg: Partial'
>>>>>
>>>>>Am I missing something?
>>>>
>>>>If SET DELETED ON, you should alse have index on DELETED().
>>>
>>>Ditto on the above, but also...
>>>
>>>Unless absolutely neccesary you should run...
>>>
>>>SELECT * FROM Chg WHERE Chg.Acctnum='5555555' INTO CURSOR cResult
>>>
>>>It will be almost instantaneous since it will be using the table as is, the equivalent of "USE chg AGAIN IN 0 ALAIS cResult". Your code will be copying fields to a temp file.
>>>
>>>HTH //:^)
>>
>>Larry, does the use of * instead of listing 2 or 3 field names really make a difference? As long as you don't use a calculated field or an "AS" clause the cursor is still a filtered copy.
>>
>>Barbara
>I do believe so. If you have access to a large table give it a try and let me know what you come up with //:^)

Barbara is right (tested on 3 million records).
Edward Pikman
Independent Consultant
Précédent
Suivant
Répondre
Fil
Voir

Click here to load this message in the networking platform