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In Firebase, is there a way to get the number of children of a node without loading all the node dat
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The code snippet you gave does indeed load the entire set of data and then counts it client-side, which can be very slow for large amounts of data.
Firebase doesn't currently have a way to count children without loading data, but we do plan to add it.
For now, one solution would be to mai...
Is it possible to use the instanceof operator in a switch statement?
...en you can simply call do() on this.
If you are not free to change A, B, and C, you could apply the visitor pattern to achieve the same.
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What are the differences between the urllib, urllib2, urllib3 and requests module?
...ython, what are the differences between the urllib , urllib2 , urllib3 and requests modules? Why are there three? They seem to do the same thing...
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Recursively counting files in a Linux directory
...IR_NAME -type f | wc -l
Explanation:
-type f to include only files.
| (and not ¦) redirects find command's standard output to wc command's standard input.
wc (short for word count) counts newlines, words and bytes on its input (docs).
-l to count just newlines.
Notes:
Replace DIR_NAME with...
How to create a shared library with cmake?
...um_required(VERSION 3.9)
You should declare a project. cmake says it is mandatory and it will define convenient variables PROJECT_NAME, PROJECT_VERSION and PROJECT_DESCRIPTION (this latter variable necessitate cmake 3.9):
project(mylib VERSION 1.0.1 DESCRIPTION "mylib description")
Declare a ne...
How SignalR works internally?
...connection. It gives you two programming models over that connection (hubs and persistent connections). SignalR has a concept of transports, each transport decides how data is sent/received and how it connects and disconnects.
SignalR has a few built in transports:
WebSockets
Server Sent Events
F...
Python Graph Library [closed]
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There are two excellent choices:
NetworkX
and
igraph
I like NetworkX, but I read good things about igraph as well. I routinely use NetworkX with graphs with 1 million nodes with no problem (it's about double the overhead of a dict of size V + E)
If you want a fe...
Query for documents where array size is greater than 1
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2.Create extra field NamesArrayLength, update it with names array length and then use in queries:
db.accommodations.find({"NamesArrayLength": {$gt: 1} });
It will be better solution, and will work much faster (you can create index on it).
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The transaction log for the database is full
...arily require lots of space for the log file, I created a second log file and made it huge. Once the project is complete we then removed the extra log file.
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Platform independent size_t Format specifiers in c?
...t), l (for long), ll (for long long), j (for intmax_t), t (for ptrdiff_t), and L (for long double). See §7.19.6.1 (7) of the C99 standard.
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