Plateforme Level Extreme
Abonnement
Profil corporatif
Produits & Services
Support
Légal
English
Fastest way to check memo field for a string
Message
De
07/07/2009 14:44:09
 
Information générale
Forum:
Visual FoxPro
Catégorie:
Codage, syntaxe et commandes
Versions des environnements
Visual FoxPro:
VFP 9 SP1
OS:
Windows XP SP2
Network:
Windows 2003 Server
Database:
MS SQL Server
Application:
Desktop
Divers
Thread ID:
01410639
Message ID:
01410656
Vues:
73
>>Assuming a memo field in a cursor is HUGE, and I want to look for a string: 'my string' what would be the fastest and least memory hog way of doing that? I think for sure that $ is not it... is alines() better? It won't be an exact match, in other words, I need to see if 'my string' is in there, but it may be in there as 'this is my string.' etc...
>>
>>I don't need to know where in the memo field it is, just whether it is there or not.
>
>
>I did some testing now (I don't know how representative they are):
>
>
>CLEAR
>CREATE CURSOR crsTest (MyMemo M)
>APPEND BLANK
>REPLACE MyMemo WITH REPLICATE([A],16000000)+[ My String]
>
>m1 = SECONDS()
>AT([My String], MyMemo)
>? [AT], SECONDS()-m1                  && 0.047
>
>m1 = SECONDS()
>RAT([My String], MyMemo)
>? [RAT], SECONDS()-m1                 && 0.053
>
>m1 = SECONDS()
>aaa = [My String] $ MyMemo
>? [$], SECONDS()-m1                   && 0.045
>
>m1 = SECONDS()
>aaa = OCCURS([My String], MyMemo)
>? [OCCURS], SECONDS()-m1              && 0.284
>
>m1 = SECONDS()
>SELECT * FROM crsTest WHERE MyMemo LIKE [%My String%] INTO CURSOR aaaa
>? [SELECT +LIKE], SECONDS()-m1        && 0.980
>
I just tested this a few times and switched the order around. It appears you are correct. While the time changes depending on whether it is first, 2nd, 3rd, etc in the order (OCCURS() versus $ etc), $ does seem to be consistently the fastest.
.·*´¨)
.·`TCH
(..·*

010000110101001101101000011000010111001001110000010011110111001001000010011101010111001101110100
"When the debate is lost, slander becomes the tool of the loser." - Socrates
Vita contingit, Vive cum eo. (Life Happens, Live With it.)
"Life is not measured by the number of breaths we take, but by the moments that take our breath away." -- author unknown
"De omnibus dubitandum"
Précédent
Suivant
Répondre
Fil
Voir

Click here to load this message in the networking platform