DBMS Collaboratory Notes

2/14

table, row/record/tuple, column/field/attribute, database instance, DBMS

3/07

cross join (Cartesian Product)
left join - most often we use this function.
##3/7
DBMS, cartesian product, column,row,table,record,

3/27

foriegn key = primary key
first step find the table, second step find the condition, third step find the solution

3/28

[0-3]\d/[A-Z][a-z][a-z]/20\d\d
Use \w to match any single alphanumeric character: 0-9 , a-z , A-Z , and _ (underscore).
Use \d to match any single digit. Use \s to match any single whitespace character.
.- means any single character.

Perl Compatible Regular Expressions (PCRE) is a regular expression C library inspired by the regular expression capabilities in the Perl programming language, written by Philip Hazel, starting in summer 1997. PCRE's syntax is much more powerful and flexible than either of the POSIX regular expression flavors and many classic regular expression libraries. The name is misleading, because PCRE and Perl each have capabilities not shared by the other.

The shorter ip address match - (\d+\.){3}\d+

everything between "" in regex - ".+?"

4/11 standard input and standard output-screen

sort < input redirection
sort > output redirection

$1 (…) = if you wanna print something then you need parenthesis.

the conbination of four highlights are the super key.

a relation is subsets of the cartition product of several sets.

5/30 Releation scheme is describtion of sets

Superkey, Candidate-key, Primary-key