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What is the “N+1 selects problem” in ORM (Object-Relational Mapping)?
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1075
Let's say you have a collection of Car objects (database rows), and each Car has a collection...
How are Python's Built In Dictionaries Implemented?
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10
You said, when both hash and the key match, it (insert op) gives up and moves on. Doesn't insert overwrite existing entry in this case?
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Convert any object to a byte[]
... Daniel DiPaoloDaniel DiPaolo
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C# Lazy Loaded Automatic Properties
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answered Oct 27 '10 at 19:20
JaredParJaredPar
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Can modules have properties the same way that objects can?
... _M).
– Alex Martelli
Apr 17 '15 at 10:59
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show 7 more comments
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Why do we need virtual functions in C++?
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answered Mar 6 '10 at 13:54
M PerryM Perry
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Extract date (yyyy/mm/dd) from a timestamp in PostgreSQL
... by suffixing it with ::date. Here, in psql, is a timestamp:
# select '2010-01-01 12:00:00'::timestamp;
timestamp
---------------------
2010-01-01 12:00:00
Now we'll cast it to a date:
wconrad=# select '2010-01-01 12:00:00'::timestamp::date;
date
------------
2010-01-01
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How to printf uint64_t? Fails with: “spurious trailing ‘%’ in format”
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tshepang
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answered Apr 27 '12 at 11:10
Anders Elias...
How can I time a code segment for testing performance with Pythons timeit?
...when you set its number argument)
import time
def myfast():
code
n = 10000
t0 = time.time()
for i in range(n): myfast()
t1 = time.time()
total_n = t1-t0
In Windows, as Corey stated in the comment, time.clock() has much higher precision (microsecond instead of second) and is preferred over t...