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What is a “Bitmap heap scan” in a query plan?
... stay in memory, but you get the point).
A bitmap index scan will sequentially open a short-list of disk pages, and grab every applicable row in each one (hence the so-called recheck cond you see in query plans).
Note, as an aside, how clustering/row order affects the associated costs with either ...
Checking if a key exists in a JavaScript object?
... testing whether a key exists. What if the key exists but the value is actually undefined?
var obj = { key: undefined };
obj["key"] !== undefined // false, but the key exists!
You should instead use the in operator:
"key" in obj // true, regardless of the actual value
If you want to check if a...
What is the use of hashCode in Java?
...
Buckets aside, hashcode is a method that the object calls to determine the order to store each object in memory. If objects are equal, then their hashcode must also be equal. (converse of this statement is false)
– NoName
Jun 24 '17 at 6:1...
Export specific rows from a PostgreSQL table as INSERT SQL script
....5.3, and my create statement was the same as yours except create view.... All I get in the output is the usual pg_dump comments and SET statements. Not sure where I'm going wrong.
– poshest
Nov 20 '16 at 15:19
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How to copy files from 'assets' folder to sdcard?
I have a few files in the assets folder. I need to copy all of them to a folder say /sdcard/folder. I want to do this from within a thread. How do I do it?
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How to disallow temporaries
For a class Foo, is there a way to disallow constructing it without giving it a name?
10 Answers
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Unable to verify leaf signature
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Note: the following is dangerous, and will allow API content to be intercepted and modified between the client and the server.
This also worked
process.env['NODE_TLS_REJECT_UNAUTHORIZED'] = '0';
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In a Django form, how do I make a field readonly (or disabled) so that it cannot be edited?
...hanged his example to work with Django 1.3, using get_readonly_fields.
Usually you should declare something like this in app/admin.py:
class ItemAdmin(admin.ModelAdmin):
...
readonly_fields = ('url',)
I've adapted in this way:
# In the admin.py file
class ItemAdmin(admin.ModelAdmin):
...
JavaScript equivalent to printf/String.Format
...low for details.
Otherwise:
Try sprintf() for JavaScript.
If you really want to do a simple format method on your own, don’t do the replacements successively but do them simultaneously.
Because most of the other proposals that are mentioned fail when a replace string of previous replaceme...
Multiple variables in a 'with' statement?
...textlib.nested, this guarantees that a and b will have their __exit__()'s called even if C() or it's __enter__() method raises an exception.
You can also use earlier variables in later definitions (h/t Ahmad below):
with A() as a, B(a) as b, C(a, b) as c:
doSomething(a, c)
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