>Hello Fabio,
>Thanks for response.
>
>Very interesting
>

> exist an index cexp with collate MACHINE
>LEFT('cstring',1)<>'%' OR '_'
>

>
>I have next simple SQL
>
>SELECT * FROM table WHERE UPPER(description) like "HP%DRUCKER" INTO CURSOR _resultset
>
>I check - no "%" and no "_" as LEFT(description,1) present
>I set SYS(3054,1,"lcOptimizeLevel")
>Execute SQL
>I'v got next result
>Using index tag descr1 to rushmore optimize table
>Using index tag deleted to rushomre optimize table
>Rushmore optimization level for table : Partial !!
>
>Why "partial" ? Difficult to understand.. Index Expression - Ok.. no "%","_"..
>
>SELECT * FROM table WHERE UPPER(description)="HP" INTO CURSOR _resultset
>
>returns "FULL"..
>
>But so far as I know.. LIKE supports rushmore optimization... whats wrong?
>
>Denis
>
>
Hi Denis, none is wrong.
VFP8SP1 have a bug on SYS(3054), and return 'partial' with every optimizable LIKE

this is fixed on VFP9SP1, and this explain

CREATE CURSOR TESTLIKE (CC C(200))
APPEND BLANK
REPLACE CC WITH ' Y  C'
INDEX ON CC COLLATE 'MACHINE' TAG T1


CLEAR

SYS(3054,12)
SET DELETED OFF
TEST()

SET DELETED ON
*
TEST()

DELETE TAG ALL

INDEX ON CC COLLATE 'MACHINE' FOR NOT DELETED() TAG T2
SET DELETED OFF
TEST2()

SET DELETED ON
*
TEST2()

PROCEDURE TEST

SELECT * FROM TESTLIKE WHERE CC LIKE 'X' INTO ARRAY AA&& DELETE OFF = 'Full'  ON = 'Partial'

SELECT * FROM TESTLIKE WHERE CC LIKE 'X%' INTO ARRAY AA && DELETE OFF = 'Full'  ON = 'Partial'

SELECT * FROM TESTLIKE WHERE CC LIKE 'X%C' INTO ARRAY AA && DELETE OFF = 'Partial'  ON = 'Partial'

PROCEDURE TEST2

SELECT * FROM TESTLIKE WHERE CC LIKE 'X' INTO ARRAY AA && DELETE OFF = 'none'  ON = 'Full'

SELECT * FROM TESTLIKE WHERE CC LIKE 'X%' INTO ARRAY AA && DELETE OFF = 'none'  ON = 'Full'

SELECT * FROM TESTLIKE WHERE CC LIKE 'X%C' INTO ARRAY AA && DELETE OFF = 'none'  ON = 'Partial'

'partial' it means that VFP doesn't complete the selection through an AND on the indexes,
but it has to make other comparisons in the record