sql server - What makes a SQL statement sargable? -


By definition (at least I have seen that) sargable means that a query is able to adapt the query engine The execution plan that uses the query I have tried to find the answer, but there is not much on the subject. So the question is, what does the SQL query segment do or does not?

The most common thing is that any document will be highly appreciated.

Which is to include an non-sessional query in that section in the function where in the block: 

  SELECT ... FROM ... WHERE year (myDate) = 2008

The SQL Optimizer can not use the ideet on an index, even if one is present. It would be really worth evaluating this function for each row of the table, using: 

  where my data & gt; = '01 -01-2008 'and myDate & lt; '01 -01-2009 '

Some other examples: 

  Bad: Select ... where is full (full name,' ed jones') = 'Ad Jones Fixed: Select ... where (full name =' ed jones') or (the full name is null)) Bad: Select ... where venture (dealer name, 4) = 'Ford' Fixed: Select ... Where Dealeram Bad like 'Ford%': Select ... Where Date Date (mm, Order Date, GateData) = 30 Fixed: Select ... Where Order Date & lt; Add Date (mm, -30, GateDat ())

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