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How do I check if an index exists on a table field in MySQL?
...re a.table_schema = 'your_schema'
and a.column_name = 'your_column'
order by a.table_schema, a.table_name;
since the joins are against INNODB_SYS_*, so the match indexes only came from INNODB tables only
share
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What's the difference between streams and datagrams in network programming?
...the server. There is a guarantee that data will not arrive in a different order than you sent it, and there is a reasonable guarantee that data will not be damaged.
A datagram socket is like passing a note in class. Consider the case where you are not directly next to the person you are passing t...
How to log cron jobs?
... @Danijel serverfault.com/a/117365/193377 0 0 * * * /some/path/to/a/file.php > $HOME/date +\%Y\%m\%d\%H\%M\%S-cron.log 2>&1
– AnneTheAgile
Oct 11 '17 at 22:11
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Cannot create an array of LinkedLists in Java…?
...e the row map type a TreeMap, and same for traversing the columns in index order, but if you don't need those cases, HashMap is quicker than TreeMap. Helper methods to get and set an arbitrary cell, handling unset null values, would be useful, of course.
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In Java, how do I check if a string contains a substring (ignoring case)? [duplicate]
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makefile execute another target
...se of parallel builds with make’s -j option?
There's a way of fixing the order. From the make manual, section 4.2:
Occasionally, however, you have a situation where you want to impose a specific ordering on the rules to be invoked without forcing the target to be updated if one of those rules is ...
Does Java SE 8 have Pairs or Tuples?
...e comparable? Should the class be final or not? Should the two elements be ordered? Should it be an interface or a class? Why stop at pairs? Why not triples, quads, or N-tuples?
And of course there is the inevitable naming bikeshed for the elements:
(a, b)
(first, second)
(left, right)
(car, cdr)...
Script Tag - async & defer
...hen you can't make them async without additional code to control execution order, but you can make them defer because defer scripts will still be executed in order, just not until after the document has been parsed. If you have that code and you don't need the scripts to run right away, you can mak...
HashSet vs LinkedHashSet
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HashSet is unordered and unsorted Set.
LinkedHashSet is the ordered version of HashSet.
The only difference between HashSet and LinkedHashSet is that:
LinkedHashSet maintains the insertion order.
When we iterate through a HashSet, t...
A 'for' loop to iterate over an enum in Java
...se of lambda and streams (Tutorial):
Stream.of(Direction.values()).forEachOrdered(System.out::println);
Why forEachOrdered and not forEach with streams ?
The behaviour of forEach is explicitly nondeterministic where as the forEachOrdered performs an action for each element of this stream, in t...