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Why does PostgreSQL perform sequential scan on indexed column?
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If the SELECT returns more than approximately 5-10% of all rows in the table, a sequential scan is much faster than an index scan.
This is because an index scan requires several IO operations for each row (look up the row in the index, then retrieve the row from the h...
finding and replacing elements in a list
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>>> a= [1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1]
>>> for n, i in enumerate(a):
... if i == 1:
... a[n] = 10
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>>> a
[10, 2, 3, 4, 5, 10, 2, 3, 4, 5, 10]
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How do you get the width and height of a multi-dimensional array?
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answered Nov 23 '10 at 19:52
Reed CopseyReed Copsey
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npm install vs. update - what's the difference?
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5 Answers
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How can I get a Bootstrap column to span multiple rows?
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5 Answers
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twig: IF with multiple conditions
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edited Oct 26 '16 at 15:55
JacobTheDev
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a...
How do I use .woff fonts for my website?
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edited Oct 10 '12 at 5:38
answered Oct 10 '12 at 5:29
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Converting from Integer, to BigInteger
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jbindeljbindel
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What does [:] mean?
... Marnach
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