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How to upgrade PostgreSQL from version 9.6 to version 10.1 without losing data?
...is the solution for Ubuntu users
First we have to stop postgresql
sudo /etc/init.d/postgresql stop
Create a new file called /etc/apt/sources.list.d/pgdg.list and add below line
deb http://apt.postgresql.org/pub/repos/apt/ utopic-pgdg main
Follow below commands
wget -q -O - https://www.postg...
How to extract a floating number from a string [duplicate]
...+]? # optional sign
... (?:
... (?: \d* \. \d+ ) # .1 .12 .123 etc 9.1 etc 98.1 etc
... |
... (?: \d+ \.? ) # 1. 12. 123. etc 1 12 123 etc
... )
... # followed by optional exponent part if desired
... (?: [Ee] [+-]? \d+ ) ?
... """
>>> rx = re.com...
C#: Printing all properties of an object [duplicate]
Is there a method built in to .NET that can write all the properties and such of an object to the console? Could make one using reflection of course, but I'm curious to if this already exists... especially since you can do it in Visual Studio in the Immediate Window. There you can an object name (wh...
How to implement a binary tree?
...ice implementation. I'm just here to point out some style stuff. python usually does node is not None instead of your (node!=None). Also, you can use the __str__ function instead of the printTree method.
– Jeff Mandell
Oct 18 '15 at 2:30
...
Immutability of Strings in Java
...t, and changing a reference. s2 still points to the same object as we initially set s1 to point to. Setting s1 to "Help!" only changes the reference, while the String object it originally referred to remains unchanged.
If strings were mutable, we could do something like this:
String s1 = "Hello";
St...
What is the difference between Google App Engine and Google Compute Engine?
...fferent events, which may include HTTP requests, changes in Cloud Storage, etc.
The biggest difference with App Engine is that functions are priced per 100 milliseconds, while App Engine's instances shut down only after 15 minutes of inactivity. Another advantage is that Cloud Functions execute imm...
What does “hashable” mean in Python?
...y and a set member, because these data structures use the hash value internally.
All of Python’s immutable built-in objects are hashable, while no mutable containers (such as lists or dictionaries) are. Objects which are instances of user-defined classes are hashable by default; they all comp...
Is there an equivalent of 'which' on the Windows command line?
...tions, aliases, files with custom executables extensions via $Env:PATHEXT, etc. defined for the current shell (quite akin to Bash's type -a foo) - making it a better go-to than other tools like where.exe, which.exe, etc which are unaware of these PowerShell commands.
Finding executables using only ...
Ruby: Can I write multi-line string with no concatenation?
...attr3, attr4, attr5, attr6, attr7
from table1, table2, table3, etc, etc, etc, etc, etc,
where etc etc etc etc etc etc etc etc etc etc etc etc etc'
Alternatively you can use a heredoc:
conn.exec <<-eos
select attr1, attr2, attr3, attr4, attr5, attr6, attr7
from ...
What are the best use cases for Akka framework [closed]
... / HA
Service backend (any industry, any app)
service REST, SOAP, cometd etc
act as message hub / integration layer
scale up, scale out, fault-tolerance / HA
Snap-in concurrency/parallelism ( any app )
Correct
Simple to work with and understand
Just add the jars to your existing JVM project (use...