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In the queries we use all the records in one table that has data which needs to be placed in a another system had a Insert, Update and Delete flags (i, u, d being 1 in the record), this way we can pull out 50 records are flagged with updated data to process rather than processing 50,000

since one record in this table has data that's got to be placed in multiple tables (and since it's an Entity Attribute Value structure, sometimes multiple attribute records in one datatype table ie. product_varchar had name, description and url) when i go to update a value i always put in the where clause WHERE tbl1.field <> tbl2.field so that way instead of updating the fields which have the same data i'm only updating the ones which are different

in terms of performance would it be better to check if the fields are different every time before making them the same or should i just update regardless

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