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Difference between “read commited” and “repeatable read”
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Read committed is an isolation level that guarantees that any data read was committed at the moment is read. It simply restricts the reader from seeing any intermediate, uncommitted, 'dirty' read. It makes no promise whatsoev...
How to get a password from a shell script without echoing
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Here is another way to do it:
#!/bin/bash
# Read Password
echo -n Password:
read -s password
echo
# Run Command
echo $password
The read -s will turn off echo for you. Just replace the echo on the last line with the command you want to run.
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Quickly reading very large tables as dataframes
...tables (30 million rows) that I would like to load as a dataframes in R. read.table() has a lot of convenient features, but it seems like there is a lot of logic in the implementation that would slow things down. In my case, I am assuming I know the types of the columns ahead of time, the table ...
read.csv warning 'EOF within quoted string' prevents complete reading of file
I have a CSV file (24.1 MB) that I cannot fully read into my R session. When I open the file in a spreadsheet program I can see 112,544 rows. When I read it into R with read.csv I only get 56,952 rows and this warning:
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Why use a READ UNCOMMITTED isolation level?
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This isolation level allows dirty reads. One transaction may see uncommitted changes made by some other transaction.
To maintain the highest level of isolation, a DBMS usually acquires locks on data, which may result in a loss of concurrency and a high locki...
Why does SIGPIPE exist?
...hout changing global signal dispositions is to temporarily mask it with pthread_sigmask, perform the write, then perform sigtimedwait (with zero timeout) to consume any pending SIGPIPE signal (which is sent to the calling thread, not the process) before unmasking it again.
I believe the reason SIGP...
How can I read a text file without locking it?
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You need to make sure that both the service and the reader open the log file non-exclusively. Try this:
For the service - the writer in your example - use a FileStream instance created as follows:
var outStream = new FileStream(logfileName, FileMode.Open,
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Only read selected columns
Can anyone please tell me how to read only the first 6 months (7 columns) for each year of the data below, for example by using read.table() ?
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Reading Xml with XmlReader in C#
I'm trying to read the following Xml document as fast as I can and let additional classes manage the reading of each sub block.
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How to read a file in reverse order?
How to read a file in reverse order using python? I want to read a file from last line to first line.
21 Answers
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