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CROSS JOIN vs INNER JOIN in SQL
...the rows, if you have 100 rows in each table with 1 to 1 match, you get 10.000 results, Innerjoin will only return 100 rows in the same situation.
These 2 examples will return the same result:
Cross join
select * from table1 cross join table2 where table1.id = table2.fk_id
Inner join
select * ...
What is the difference between partitioning and bucketing a table in Hive ?
...s, your file structure will look something like below.
server_date=xyz
00000_0
00001_0
00002_0
........
00010_0
Here server_date=xyz is the partition and 000 files are the buckets in each partition. Buckets are calculated based on some hash functions, so rows with name=Sandy will always go in...
In which order should floats be added to get the most precise result?
...t are accurate at the scale of the largest-magnitude value in the input (0.0000001% out), but for 4 of them the result is inaccurate at the scale of the true solution (100% out). The particular problem you're solving will tell you whether the former is good enough or not.
In fact, you can play a lo...
How exactly does CMake work?
...KLOC, maybe up to 100KLOG, using CMake seems a little bit like using a 100,000 dollar forestry tree removal machine to remove weeds from your 2 foot by 2 foot flower garden. (By the way, if you've never seen such a machine, you should look for one on youtube, they're amazing)
If your build system ...
How do you Encrypt and Decrypt a PHP String?
...e password-hashing algorithms:
Argon2
scrypt
bcrypt
PBKDF2-SHA256 with 86,000 iterations
Never use a general-purpose hash function (MD5, SHA256) for password storage.
Don't encrypt URL Parameters. It's the wrong tool for the job.
PHP String Encryption Example with Libsodium
If you are on PHP < ...
How to detect if a script is being sourced
...othing really related...
You could even check that $SECONDS is close to 0.000, but that's ensure only manualy sourced cases...
You even could try to check for what's parent is:
Place this into your testfile.ksh:
ps $PPID
Than:
./testfile.ksh
PID TTY STAT TIME COMMAND
32320 pts/4 S...
How dangerous is it to compare floating point values?
...he result would need 25 bits of precision. Instead, it gets rounded (to 0x2000000 in the default rounding mode).
The fact that many results get rounded due to needing infinitely many places for the correct value. This includes both rational results like 1/3 (which you're familiar with from decimal w...
Build an ASCII chart of the most commonly used words in a given text [closed]
...
One good way to save is by changing 0.000 to just 0, then using -C instead of 1.0/C. And making FLOAT into REAL will save a stroke too. The biggest thing, though, is that it looks like you have lots of AS instances that should be optional.
–...
What are good examples of genetic algorithms/genetic programming solutions? [closed]
...nerations of this, I ended up with a population of genes that could turn $5000 into an average of about $10000 with no chance of death/brokeness (on the historical data, of course).
Unfortunately, I never got the chance to use this system live, since my boss lost close to $100,000 in less than 3 mo...
What is 'Context' on Android?
.... the Context, and the execStartActivity makes use of this context.
A 30,000 overview is this: the Instrumentation class keeps tracks of a list of Activities that it’s monitoring in order to do its work. This list is used to coordinate all of the activities and make sure everything runs smoothly...