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COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better? [duplicate]
...to each other, they are entirely different thing, they just share a common token, i.e. *.
An alternate syntax
In fact, if it is not permitted to name a field as same as its table name, RDBMS language designer could give COUNT(tableNameHere) the same semantics as COUNT(*). Example:
For counting ro...
Mongoose (mongodb) batch insert?
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insertMany doesn't work for me. I got a fatal error allocation failed. But if I use collection.insert It works perfectly.
– John
Dec 12 '16 at 13:03
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What does passport.session() middleware do?
...y Express, is a unique ID which is roughly equivalent to an authentication token that the browser sends with every request. The data stored in this session is used to restore the authentication state of the user.
– Jared Hanson
Feb 27 '14 at 16:07
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Improve INSERT-per-second performance of SQLite
...formed (which in this loop is always the case). This will save you several allocate, copy and deallocate operations per loop. Possibly a large improvement.
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How do you add an array to another array in Ruby and not end up with a multi-dimensional result?
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@phatmann Concatenation with Array#concat does not allocate a new array, Concatenation with Array#+ does
– cbliard
Jul 21 '14 at 9:19
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Java ByteBuffer to String
...wers may not work with a ByteBuffer that's been created through ByteBuffer.allocateDirect().
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Convert HTML to NSAttributedString in iOS
...can initialize an NSAttributedString using HTML, eg:
[[NSAttributedString alloc] initWithData:[htmlString dataUsingEncoding:NSUTF8StringEncoding]
options:@{NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType,
NSCharact...
Flask-SQLalchemy update a row's information
... the json data into update query:
class UpdateUserDetails(Resource):
@auth_token_required
def post(self):
json_data = request.get_json()
user_id = current_user.id
try:
userdata = User.query.filter(User.id==user_id).update(dict(json_data))
db.session.commit()
msg={...
How is the default max Java heap size determined?
...cts to require it. A much smaller amount, termed the initial heap size, is allocated during JVM initialization. ...
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Server JVM heap configuration ergonomics are now the same as the Client, except that the default maximum heap size for 32-bit JVMs is 1 gigabyte, corresponding to a physical me...
Avoiding memory leaks with Scalaz 7 zipWithIndex/group enumeratees
... -- I tested with 2^14 32MiB arrays (i.e., a total of half a TiB of memory allocated over time).
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