Mike Yearwood
Toronto, Ontario, Canada
Information générale
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
>>for tables without any memo fields:
>>Was wondering if anyone knew at what precentage point deleted records casue a significant performance hit when doing SQL statements.
>>Is it a basic standard or does it depend on the number of fields and/or type of fields.
>
>Imho, they don't cause performance hit, because if SET DELETED ON, VFP will have to check for deleted records regardless if they are in a table or not.
It's more complicated than that. With SET DELETED ON if there is an index tag, this tag will be brought from the server to the PC for examination. That can be a substantial wait time as Chris Probst pointed out in FPA.
Without the tag, other aspects of the query will filter out the records and SET DELETED will have far fewer records to examine.
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