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How to listen for changes to a MongoDB collection?
I'm creating a sort of background job queue system with MongoDB as the data store. How can I "listen" for inserts to a MongoDB collection before spawning workers to process the job? Do I need to poll every few seconds to see if there are any changes from last time, or is there a way my script can wa...
Why are variables “i” and “j” used for counters?
... Yes, FORTRAN originates these conventions.
– Jé Queue
Nov 10 '10 at 0:26
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I was taught I th...
Waiting on a list of Future
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To timeout waiting for a future to appear on the queue there is a poll(seconds) method on the CompletionService.
– dcernahoschi
Oct 13 '13 at 18:16
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How to edit incorrect commit message in Mercurial? [duplicate]
...d including the selected revision from Mercurial changesets into Mercurial Queue patches. Select the Patch you want to modify the message for, and it should automatically change the screen to the MQ editor. Edit the message which is in the middle of the screen, then click QRefresh. Finally, right cl...
Postgres: clear entire database before re-creating / re-populating from bash script
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Although the following line is taken from a windows batch script, the command should be quite similar:
psql -U username -h localhost -d postgres -c "DROP DATABASE \"$DATABASE\";"
This command is used to clear the whole database, by actually dropping it. The $DATABASE (in Wi...
What does .SD stand for in data.table in R
...h among character/factor/numeric are common. We can use .SD and .SDcols to batch-convert groups of such columns.
We notice that the following columns are stored as character in the Teams data set:
# see ?Teams for explanation; these are various IDs
# used to identify the multitude of teams from
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Delete commits from a branch in Git
... Note: If you happen to have any --no-ff merges in that last batch of commits, rebase will butcher them :( This is mentioned under -p on this page. The problem is, if you replace -i with -p, you no longer get that pop up with the choices for "edit this commit, sqush that one", etc etc....
What is the difference between a database and a data warehouse?
...ources.
Data capture - Bulk write operations typically on a predetermined batch schedule.
Data normalization - Denormalized schemas, such as the Star schema or Snowflake schema.
Data storage - Optimized for simplicity of access and high-speed query. performance using columnar storage.
Data acces...
What is boxing and unboxing and what are the trade offs?
...ry<TKey, UValue>
SortedDictionary<TKey, UValue>
Stack<T>
Queue<T>
LinkedList<T>
were all designed to overcome the performance issues of boxing and unboxing in previous collection implementations.
For more, see chapter 16, CLR via C# (2nd Edition).
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How can I convert my Java program to an .exe file? [closed]
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You could make a batch file with the following code:
start javaw -jar JarFile.jar
and convert the .bat to an .exe using any .bat to .exe converter.
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