When I optimize my 2 single queries to run in less than 0.02 seconds and then UNION them the resulting query takes over 1 second to run. Also, a UNION ALL takes longer than a UNION DISTINCT.

I would assume allowing duplicates would make the query run faster and not slower. Am I really just better off running the 2 queries separately? I would prefer to use the UNION.

As a simple example if I do 

SELECT name FROM t1 WHERE field1 = true

it takes .001 seconds

and if I do 

SELECT name FROM t1 WHERE field1 = false

it takes .1 seconds.

If I then run 

SELECT name FROM t1 WHERE field1 = true 
UNION ALL 
SELECT name FROM t1 WHERE field1 = false

it takes over 1 second.

mysql query-optimization union
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