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C++ unordered_map using a custom class type as the key
...called "bucket count". A bucket is a slot in the container's internal hash table, see e.g. unordered_map::bucket_count for more information.
– honk
Feb 15 at 8:23
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Difference between timestamps with/without time zone in PostgreSQL
...d '2011-07-01 06:30:30+05' is ignored but i'm able to do insert into test_table (date) values ('2018-03-24T00:00:00-05:00'::timestamptz); and it will convert it to utc correctly. where date is timestamp without timezone. I'm trying to understand what the main value of timestamp with timezone is an...
Redis strings vs Redis hashes to represent JSON: efficiency?
...d HSET commands is still O(1): the hash will be converted into a real hash table as soon as the number of elements it contains will grow too much
But you should not worry, you'll break hash-max-ziplist-entries very fast and there you go you are now actually at solution number 1.
Second option wil...
What characters are allowed in an email address?
...
I've tried to implement this in postfix via pcre access table under a check_recipient_access restriction, first turning the 3 long pcres (from the linked page) into one line each and topping and tailing thus: /^[...pcre..]$/ DUNNO, then adding a final line /.*/ REJECT, but it stil...
Please explain the exec() function and its family
...o forth.
But they're not required to be used together. It's perfectly acceptable for a program to call fork() without a following exec() if, for example, the program contains both parent and child code (you need to be careful what you do, each implementation may have restrictions).
This was used qui...
Heap vs Binary Search Tree (BST)
...log(n) n
Delete worst log(n) log(n)
All average times on this table are the same as their worst times except for Insert.
*: everywhere in this answer, BST == Balanced BST, since unbalanced sucks asymptotically
**: using a trivial modification explained in this answer
***: log(n) for p...
How efficient is locking an unlocked mutex? What is the cost of a mutex?
... system limit. But too many of them spells nightmare for debugging. Simple table:
Less locks means more contentions (slow syscalls, CPU stalls) and lesser parallelism
Less locks means less problems debugging multi-threading problems.
More locks means less contentions and higher parallelism
More lo...
Performance optimization strategies of last resort [closed]
... constantly figuring out things that the programmer knows are fairly predictable. In other words, don't "interpret" the sequence of things to do, "compile" it.
That redesign is done, shrinking the source code by a factor of 4, and the time is reduced to 10 seconds.
Now, because it's getting so q...
How to write WinForms code that auto-scales to system font and dpi settings?
...f you are not using Dock
modes or a Layout Manager like FlowLayoutPanel or TableLayoutPanel.
Base classes derived from ContainerControl should leave AutoScaleMode set to Inherit (the default value set in class ContainerControl; but NOT the default set by the designer). If you set it to anything else...
urlencode vs rawurlencode?
... string before return.
Grand Summary
Both use the same hexchars lookup table
URIEncode doesn't terminate a string with \0, raw does.
If you're working in EBCDIC I'd suggest using RawUrlEncode, as it manages the ~ that UrlEncode does not (this is a reported issue). It's worth noting that ASCII an...