1. 1NF - First Normal Form states that all tuple values should be atomic. Atomic means that there should be only one useful piece of data for each attribute.

The first step in database normalization is to determine the functional dependencies in the database. This means to find which values are determined by which.

2. Decomposition and Boyce/Codd Normal Form

BCNF has only one requirement - every functional dependency must be functionally determined by either a candidate key*, or a superset of a candidate key( superkey).

*A candidate key is a set of attributes that must be unique for each tuple and irreducible into a smaller key.

Example:

candidate_key -> value

candidate_key2 -> value2

...

5. 5th Normal Form requires that each join dependency is satisfied by superkeys.

A join dependency(JD) is a set of projections on a relation which when joined reform the original relation.

mysql> LOAD DATA INFILE 'file.csv' INTO TABLE table_name FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"' LINES TERMINATED BY '\r\n' (column1, column2);

It gives you all the options such as how fields are terminated, enclosed and so on. The above example is specific for a csv file created with a Windows Text Editor. (windows... haha)

Similarly, if you have to export a query into a text file here is how this can be done:

mysql> SELECT column1, column2 INTO OUTFILE 'file.csv' FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"'LINES TERMINATED BY '\r\n' FROM table_name;

If improper privileges are applied this can lead to a website being hacked via MySQL. This means that the attacker executes a MySQL query which either illegally retrieves, updates or inserts information.

Thus when you manually assign privileges make sure not to grant only the needed privileges to the corresponding tables. This is not always possible though since many popular web applications use just one user for everything.
So here is the usual MySQL privileges granting:

GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP,ALTER,INDEX ON database.* TO user@localhost IDENTIFIED BY 'password';

This will grant all privileges to user@localhost. However, imagine that you can divide your script into parts with different functionality. For example, user_logs would be used to read just the logs from the 'logs' table. Then his privileges should be:

GRANT SELECT ON database.logs TO user_logs@localhost IDENTIFIED BY 'password';

This will make sure that even compromised user_logs will not be able to mess with the entire database.
MySQL privileges assignment is a complex process which allows you to set different privileges for an user for different tables/databases. However, this process is very often neglected and users are granted with all privileges for a whole database.

If improper privileges are applied this can lead to a website being hacked via MySQL. This means that the attacker executes a MySQL query which either illegally retrieves, updates or inserts information.

Thus when you manually assign privileges make sure not to grant only the needed privileges to the corresponding tables. This is not always possible though since many popular web applications use just one user for everything.

So here is the usual MySQL privileges granting:

GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP,ALTER,INDEX ON database.* TO user@localhost IDENTIFIED BY 'password';

This will grant all privileges to user@localhost. However, imagine that you can divide your script into parts with different functionality. For example, user_logs would be used to read just the logs from the 'logs' table. Then his privileges should be:

GRANT SELECT ON database.logs TO user_logs@localhost IDENTIFIED BY 'password';

This will make sure that even compromised user_logs will not be able to mess with the entire database.

root@server:/var/lib/mysql# /etc/init.d/mysql start

Starting MySQL. ERROR! Manager of pid-file quit without updating file.

There were all kind of suggestions about it on the net, most of which had something to do with incorrect shutdown or incorrect permissions for the pid file.

One of the suggestions reminded me to read the mysql error log Here is what the error log said:

root@server:/var/lib/mysql# tail -f /var/lib/mysql/host.server.bgsnow.com.err

InnoDB: Restoring possible half-written data pages from the doublewrite

InnoDB: buffer...

InnoDB: Doing recovery: scanned up to log sequence number 0 43655

091114 13:16:20  InnoDB: Starting an apply batch of log records to the database...

InnoDB: Progress in percents: 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99

InnoDB: Apply batch completed

091114 13:16:21  InnoDB: Started; log sequence number 0 43655

091114 13:16:21 [ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.host' doesn't exist

091114 13:16:21  mysqld ended

Obviously I have forgotten to move back the mysql directory which is responsible for the database for all privileges, databases and so on  So moving it back along with the rest of the core files solved the problem:

root@server:/var/lib/mysql# mv ../mysqlOLD/* ./

mv: overwrite `./host.server.bgsnow.com.err'? y

mv: overwrite `./ibdata1'? n

mv: overwrite `./ib_logfile0'? n

mv: overwrite `./ib_logfile1'? n

mv: overwrite `./mysql-slow.log'? y

root@server:/var/lib/mysql# /etc/init.d/mysql restart

Shutting down MySQL. SUCCESS!

Starting MySQL. SUCCESS!

Thus if you have similar problems, the first thing is to check the MySQL error log and don't believe the misleading error about the PID