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What's the difference between Task.Start/Wait and Async/Await?
...e another thread is doing the work, and that thread has been assigned to a CPU, so the work is actually being done. Maybe the work is being done by hardware and there is no thread at all. But surely, you say, there must be some thread in the hardware. No. Hardware exists below the level of thread...
Grepping a huge file (80GB) any way to speed it up?
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If you have a multicore CPU, I would really recommend GNU parallel. To grep a big file in parallel use:
< eightygigsfile.sql parallel --pipe grep -i -C 5 'db_pd.Clients'
Depending on your disks and CPUs it may be faster to read larger blocks:
...
What are bitwise operators?
...ut bit on the bottom line. So the answer to the above expression is 4. The CPU has done (in this example) 8 separate "AND" operations in parallel, one for each column.
I mention this because I still remember having this "AHA!" moment when I learned about this many years ago.
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Fast way of finding lines in one file that are not in another?
...iently large that storing them both causes a memory problem, you can trade CPU for memory by storing only file1 and deleting matches along the way as file2 is read.
BEGIN { FS="" }
(NR==FNR) { # file1, index by lineno and string
ll1[FNR]=$0; ss1[$0]=FNR; nl1=FNR;
}
(NR!=FNR) { # file2
if ($0 ...
How do I create a unique constraint that also allows nulls?
...onal disk space.
Note that if you don't want an index, you can still save CPU by making the expression be precalculated to disk by adding the keyword PERSISTED to the end of the column expression definition.
In SQL Server 2008 and up, definitely use the filtered solution instead if you possibly ca...
Should I instantiate instance variables on declaration or in the constructor?
...ow it was him). Personal taste is personal taste; ultimately, neither the CPU nor the JRE care about syntactical style.
– Aquarelle
Sep 20 '13 at 22:38
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How do I automatically update a timestamp in PostgreSQL
... Says so in the Postgres documentation of the types. Varchar has extra CPU cycles to check for the constraint, which doesn't happen on TEXT.
– Rahly
Jun 21 '17 at 15:50
3
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How to destroy an object?
...for "speed", but if you want to reclaim memory immediately (at the cost of CPU) should want to use null.
Like others mentioned, setting to null doesn't mean everything is reclaimed, you can have shared memory (uncloned) objects that will prevent destruction of the object. Moreover, like others h...
What is non-blocking or asynchronous I/O in Node.js?
...ng, asynchronous operations is that you can maximize the usage of a single CPU as well as memory.
Synchronous, blocking example
An example of synchronous, blocking operations is how some web servers like ones in Java or PHP handle IO or network requests. If your code reads from a file or the datab...
HTTP vs HTTPS performance
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The overhead is NOT due to the encryption. On a modern CPU, the encryption required by SSL is trivial.
The overhead is due to the SSL handshakes, which are lengthy and drastically increase the number of round-trips required for a HTTPS session over a HTTP one.
Measure (using a ...