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Possible to perform cross-database queries with PostgreSQL?
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Just to add a bit more information.
There is no way to query a database other than the current one. Because PostgreSQL loads database-specific system catalogs, it is uncertain how a cross-database query should even behave.
contrib/dblink ...
Querying data by joining two tables in two database on different servers
...n the remote server and transfer only the data back to you. This can be a bit faster, and it will let the remote server optimize your query. If you cache the data in a temporary (or in-memory) table on DB1 in the example above, then you'll be able to query it just like joining a standard table. F...
Automate ssh-keygen -t rsa so it does not ask for a passphrase
...sa -N ''
As noted in man ssh-keygen :
SYNOPSIS
ssh-keygen [-q] [-b bits] [-t dsa | ecdsa | ed25519 | rsa | rsa1] [-N new_passphrase] [-C comment] [-f output_keyfile]
(...)
-q Silence ssh-keygen.
(that is with openssh-client package in Debian 9.4 stretch : OpenSSH_6.7p1 Debian-5+...
How to count certain elements in array?
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[this answer is a bit dated: read the edits]
Say hello to your friends: map and filter and reduce and forEach and every etc.
(I only occasionally write for-loops in javascript, because of block-level scoping is missing, so you have to use a ...
How to easily resize/optimize an image size with iOS?
...ge in its original size, I'm planning on resizing the image to something a bit smaller to save on space/performance.
18 Ans...
Advantages of stateless programming?
... of interactions it can have with the rest of the program.
That's the big win from 'immutability' IMO. In an ideal world, we'd all design terrific APIs and even when things were mutable, effects would be local and well-documented and 'unexpected' interactions would be kept to a minimum. In the re...
C++, Free-Store vs Heap
...t you NEVER mix "new" and "delete" with "malloc", "realloc", or "free" (or bit level sets for that matter).
During interviews it's good to say that "new and delete use the free store, malloc and free use the heap; new and delete call the constructor and destructor, respectively, however malloc and f...
The Definitive C++ Book Guide and List
...dard (INCITS/ISO/IEC 14882:2011/2014/2017) This, of course, is the final arbiter of all that is or isn't C++. Be aware, however, that it is intended purely as a reference for experienced users willing to devote considerable time and effort to its understanding. The C++17 standard is released in elec...
Convert.ChangeType() fails on Nullable Types
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This is a little bit long-ish for an example, but this is a relatively robust approach, and separates the task of casting from unknown value to unknown type
I have a TryCast method that does something similar, and takes nullable types into a...
Is there a “do … until” in Python? [duplicate]
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I prefer to use a looping variable, as it tends to read a bit nicer than just "while 1:", and no ugly-looking break statement:
finished = False
while not finished:
... do something...
finished = evaluate_end_condition()
...