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Fastest check if row exists in PostgreSQL
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How about simply:
select 1 from tbl where userid = 123 limit 1;
where 123 is the userid of the batch that you're about to insert.
The above query will return either an empty set or a single row, depending on whether there are records with the given userid.
If this turns o...
What kind of virtual machine is BEAM (the Erlang VM)?
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The Erlang VM runs as one OS process. By default it runs one OS thread per core to achieve maximum utilisation of the machine. The number of threads and on which cores they run can be set when the VM is started.
Erlang processes are implemented entir...
How do I run Asynchronous callbacks in Playground
...swered Nov 25 '16 at 10:58
bradd123bradd123
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...
How do I upgrade PHP in Mac OS X?
... may want to check out Marc Liyanage's PHP package. It comes in a nice Mac OS X installer package that you can double-click. He keeps it pretty up to date.
http://php-osx.liip.ch/
Also, although upgrading to Snow Leopard won't help you do PHP updates in the future, it will probably give you a newe...
Insert all values of a table into another table in SQL
...dited Feb 26 '14 at 1:12
hichris123
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answered Apr 21 '10 at 9:35
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If statement in aspx page
...erver">
<% If Request.QueryString("id_query_param") = 123 Then 'Add some VB comment here,
'which will not be visible in the rendered source code of the aspx page later %>
<!-- add some html content depending on -->
<!-- the conditi...
Conditional import of modules in Python
In my program I want to import simplejson or json based on whether the OS the user is on is Windows or Linux. I take the OS name as input from the user. Now, is it correct to do the following?
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“java.lang.OutOfMemoryError : unable to create new native Thread”
... into using Callable/Runnables under the control of an Executor if at all possible. There are plenty of standard executors with various behavior which your code can easily control.
(There are many reasons why the number of threads is limited, but they vary from operating system to operating system...
Read text file into string array (and write)
...with Scanner:
package main
import (
"bufio"
"fmt"
"log"
"os"
)
// readLines reads a whole file into memory
// and returns a slice of its lines.
func readLines(path string) ([]string, error) {
file, err := os.Open(path)
if err != nil {
return nil, err
}
defe...
How do I fetch a single model in Backbone?
...ers with the hashbang in your URL like so, http://www.mydomain.com/#clocks/123 , but it should work even if you haven't yet.
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