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Efficient way to rotate a list in python
...s in the list following the popped item, because the data structure shifts all following elements toward the front of the list. Only the last element can be popped in O(1) time for this reason.
– Kirk Boyer
Jun 17 '18 at 21:26
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Effect of NOLOCK hint in SELECT statements
...l complete faster than a normal select.
2) Yes, a select with NOLOCK will allow other queries against the effected table to complete faster than a normal select.
Why would this be?
NOLOCK typically (depending on your DB engine) means give me your data, and I don't care what state it is in, and d...
Changing the case of a string in Eclipse
... You can use the hot key CTRL+SHIFT+L to bring up the popup that contains all the available hot-keys
– Ken Chan
Oct 4 '12 at 18:57
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What is the difference between $(command) and `command` in shell programming?
... for portability issues it is recommended to use backticks for non-nested calls. $(...) needs a recursive parser but this was not used with ksh86 that introduced the feature. Check in-ulm.de/~mascheck/various/cmd-subst for a list of correct implementations. A conforming shell needs to support all c...
Why are Docker container images so large?
I made a simple image through Dockerfile from Fedora (initially 320 MB).
8 Answers
8
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How to redirect output to a file and stdout
In bash, calling foo would display any output from that command on the stdout.
10 Answers
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C++ - passing references to std::shared_ptr or boost::shared_ptr
...now that sp->do_something() will not blow up due to a null pointer?
It all depends what is in those '...' sections of the code. What if you call something during the first '...' that has the side-effect (somewhere in another part of the code) of clearing a shared_ptr to that same object? And wha...
Difference between volatile and synchronized in Java
...om obtaining the monitor (or lock) for the same object, thereby preventing all code blocks protected by synchronization on the same object from executing concurrently. Synchronization also creates a "happens-before" memory barrier, causing a memory visibility constraint such that anything done up t...
Is there a naming convention for Django apps
...-app" would be a syntax error). PEP 8 says:
Modules should have short, all-lowercase names. Underscores can be used
in the module name if it improves readability. Python packages should
also have short, all-lowercase names, although the use of underscores is
discouraged.
So, 1 and 3 ar...
How to select all records from one table that do not exist in another table?
...e = t1.name
WHERE t2.name IS NULL
Q: What is happening here?
A: Conceptually, we select all rows from table1 and for each row we attempt to find a row in table2 with the same value for the name column. If there is no such row, we just leave the table2 portion of our result empty for that row. The...