Why does the Contains() operator degrade Entity Framework's performance so dramatically?

Why does the Contains() operator degrade Entity Framework's performance so dramatically?

c# sql performance entity-framework-4 contains

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How can I tell if a VARCHAR variable contains a substring?

sql string contains sql-server-2012

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What is the linq equivalent to the SQL IN operator

sql linq contains

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How does contains() in PL-SQL work?

sql oracle oracle10g contains

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Checking if array is contained in another array in PostgreSQL

sql arrays postgresql contains

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Postgresql Contains in where clause

sql postgresql select where-clause contains

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