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How to debug Lock wait timeout exceeded on MySQL?
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What gives this away is the word transaction. It is evident by the statement that the query was attempting to change at least one row in one or more InnoDB tables.
Since you know the query, all the tables being accessed are candidates for being the culprit.
From there, ...
How does Java handle integer underflows and overflows and how would you check for it?
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If it overflows, it goes back to the minimum value and continues from there. If it underflows, it goes back to the maximum value and continues from there.
You can check that beforehand as follows:
public static boolean willAdd...
Secure hash and salt for PHP passwords
It is currently said that MD5 is partially unsafe. Taking this into consideration, I'd like to know which mechanism to use for password protection.
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Optimise PostgreSQL for fast testing
I am switching to PostgreSQL from SQLite for a typical Rails application.
2 Answers
2
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Using Kafka as a (CQRS) Eventstore. Good idea?
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Kafka is meant to be a messaging system which has many similarities to an event store however to quote their intro:
The Kafka cluster retains all published messages—whether or not they
have been consumed—for a configurable period of time. For example if
the retention is set ...
Is git's semi-secret empty tree object reliable, and why is there not a symbolic name for it?
Git has a well-known, or at least sort-of-well-known, empty tree whose SHA1 is:
3 Answers
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Class does not implement its superclass's required members
...want to be NSCoding-compatible is to do something like this:"
required init(coder: NSCoder) {
fatalError("NSCoding not supported")
}
If you know you don't want to be NSCoding compliant, this is an option. I've taken this approach with a lot of my SpriteKit code, as I know I won't be loading it...
Pointers vs. values in parameters and return values
... channels, strings, function values, and interface values are implemented with pointers internally, and a pointer to them is often redundant.
Elsewhere, use pointers for big structs or structs you'll have to change, and otherwise pass values, because getting things changed by surprise via a pointer ...
std::wstring VS std::string
..._t.
char vs. wchar_t
char is supposed to hold a character, usually an 8-bit character.
wchar_t is supposed to hold a wide character, and then, things get tricky:
On Linux, a wchar_t is 4 bytes, while on Windows, it's 2 bytes.
What about Unicode, then?
The problem is that neither char nor wchar_t...
When to Redis? When to MongoDB? [closed]
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I would say, it depends on kind of dev team you are and your application needs.
For example, if you require a lot of querying, that mostly means it would be more work for your developers to use Redis, where your data might be stored in v...