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Why are joins bad when considering scalability?
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...except in MySQL, which seems to have performance problems with large numbers of joins regardless of how your indexes look. Or at least it has in the past.
– Powerlord
Apr 12 '10 at 17:53
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Get OS-level system information
... Runtime.getRuntime().totalMemory());
/* Get a list of all filesystem roots on this system */
File[] roots = File.listRoots();
/* For each filesystem root, print some info */
for (File root : roots) {
System.out.println("File system root: " + root.getAbsolutePath());
Sy...
ORA-00979 not a group by expression
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@AaronDigulla That's what MySQL does, and the world didn't end :p
– Chris Baker
Aug 27 '14 at 21:32
1
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Should I use px or rem value units in my CSS? [closed]
... <div> - 1.25px
The CSS3 rem, which is always relative only to the root html element, is now supported on 96% of all browsers in use.
The Opinion
I think everyone agrees that it's good to design your pages to be accommodating to everyone, and to make consideration for the visually impaire...
Getting root permissions on a file inside of vi? [closed]
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If you need root privileges to save a new file, replace % with the name (including path) of the new file.
– gvkv
Aug 10 '10 at 0:47
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Verify a certificate chain using openssl verify
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If a certificate is found which is its own issuer it is assumed to be the root CA.
In other words, root CA needs to self signed for verify to work. This is why your second command didn't work. Try this instead:
openssl verify -CAfile RootCert.pem -untrusted Intermediate.pem UserCert.pem
It will v...
gdb fails with “Unable to find Mach task port for process-id” error
...nks. This plus code signing were required to get gdb to work. I gave gdb root access (as described here stackoverflow.com/questions/10476154/…) so I didn't have to type sudo each time. Edit - Found a better approach here: stackoverflow.com/a/10441587/305149
– Aneil Mallava...
Add primary key to existing table
...primary key for sql table.
First, you have to drop your old primary key.
MySQL:
ALTER TABLE Persion
DROP PRIMARY KEY;
SQL Server / Oracle / MS Access:
ALTER TABLE Persion
DROP CONSTRAINT 'constraint name';
You have to find the constraint name in your table. If you had
given constraint n...
Call to undefined method mysqli_stmt::get_result
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Please read the user notes for this method:
http://php.net/manual/en/mysqli-stmt.get-result.php
It requires the mysqlnd driver... if it isn't installed on your webspace you will have to work with BIND_RESULT & FETCH!
https://secure.php.net/manual/en/mysqli-stmt.bind-result.php
https://s...
How do I check CPU and Memory Usage in Java?
... }
public String DiskInfo() {
/* Get a list of all filesystem roots on this system */
File[] roots = File.listRoots();
StringBuilder sb = new StringBuilder();
/* For each filesystem root, print some info */
for (File root : roots) {
sb.append...