Setting in FSTAB add HDD in FreeBSD or Unix

ee /etc/fstab

/dev/da2s1 /studentdata ufs rw 2 2

Script to rename multiple table in MySQL

Baru-baru ni aku faced problem untuk rename table prefix secara pukal...kat database tu ada 186 tables...
kalau nak tukar satu-satu...pergghh...memang lebam...setelah google punya google...aku jumpa solution ni...tapi kena pakai ruby script dan tukar ke sql statement..tapi kalau korang nak pakai convert ke php pun x de hal...guna concept yg sama jek...

Ikut ni :

1. masuk mysql...pastu show tables;
2. copy semua tables yg korang nak rename tu...
3. paste kat dlm script ni (dlm cth ni aku bagi nama file ni batch_rename.sh ) :
   
   OLD_PREFIX = "mdl"
   NEW_PREFIX = "mdlsirap"
   data=<<-EOD | mdl_assignment | | mdl_assignment_submissions | | mdl_backup_config | | mdl_backup_courses | | mdl_backup_files | | mdl_backup_ids | | mdl_backup_log | | mdl_block | | mdl_block_instance |
   | mdl_block_pinned |
   EOD
   tables = []
   data.each_line do |line|
   if line=~/(#{OLD_PREFIX}\w+)/
   puts "RENAME TABLE #{$1} TO #{NEW_PREFIX}#{$1};"
   end
   end
   
   
4. Pastu runkan script ni pakai ruby punya command-line (aku assume korang dah install ruby) :
   #ruby batch_rename.sh
5. Dia akan kluar output :
   RENAME TABLE mdl_assignment TO mdlsirap_assignment;
   RENAME TABLE mdl_assignment_submissions TO mdlsirap_assignment_submissions;
   RENAME TABLE mdl_backup_config TO mdlsirap_backup_config;
   RENAME TABLE mdl_backup_courses TO mdlsirap_backup_courses;
   RENAME TABLE mdl_backup_files TO mdlsirap_backup_files;
   RENAME TABLE mdl_backup_ids TO mdlsirap_backup_ids;
   RENAME TABLE mdl_backup_log TO mdlsirap_backup_log;
   RENAME TABLE mdl_block TO mdlsirap_block;
   RENAME TABLE mdl_block_instance TO mdlsirap_block_instance;
   RENAME TABLE mdl_block_pinned TO mdlsirap_block_pinned;
6. just masukan sql statement ni dlm satu file lain...tapi kalau nak senang...buat step no. 4 tu camni :
   #ruby batch_rename.sh > a.sql
7. Runkan sql file tu guna mysql...:
   #mysql namadatabase <>
8. Selesai....

Credit to Sirap.Dol.

Enable the query cache in MySQL to improve performance

from mysql server

$ mysql -u root –p

set cache inside mysql shell



mysql> SET GLOBAL query_cache_size = 16777216;

mysql> SHOW VARIABLES LIKE 'query_cache_size';

exit and edit my.cnf

(on ubuntu)
cd /etc/mysql/my.cnf

# nano /etc/my.cnf

add

query_cache_size = 268435456
query_cache_type=1
query_cache_limit=1048576

SUDO in FreeBSD / Unix

as root install

sudo located at /usr/ports/security/sudo
make configure
make && make install

edit conf at

ee /usr/local/etc/sudoers

example and edit :

# Runas alias specification

# User privilege specification
root ALL=(ALL) ALL
kenan ALL=(www) ALL

example :
usename ALL=(group) ALL


** note : !/usr/bin/su (this will prevent user to sudo su)

Set environment : setenv EDITOR ee


General sudoers File Record Format
usernames/group servername = (usernames command can be run as) command

example using sudo :

-list the dir-
sudo -u www ls -lah /usr/local/www/apache22/data/

-create a file-
sudo -u www touch /usr/local/www/apache22/data/test

- edit a file-
sudo -u www ee /usr/local/www/apache22/data/test

Can't create table (errno: 708) (Mysql BUGS)

I recently face my mysql problem like this.

mysql> alter table 19m4t_enrol_authorize engine=ndbcluster;
ERROR 1005 (HY000): Can't create table './lmsdb/#sql-2ece_a.frm' (errno: 708)

when i want to cluster my tables on my other nodes this error appear.

The Solution is go to my mysql management node and i increase

increase "MaxNoOfAttributes"

into my ndb_mgm.conf

example :

DataMemory = 24G
IndexMemory = 4G
MaxNoOfOrderedIndexes = 1024
MaxNoOfAttributes = 10000
MaxNoOfTables = 2500
MaxNoOfConcurrentOperations = 250000
MaxNoOfConcurrentIndexOperations = 250000

reboot all machine.

DONE!