Archive for February, 2011

Database Size

February 8, 2011 Leave a comment

dba_data_files –  means total size of the data file.

The data file size is total of dba_free_space and dba_segments:
dba_data_files = dba_free_space + dba_segments

dba_segments – means used size of the data file

dba_free_space – means free size of the data file

Size Check Queries:

To get total datafiles size, free and used space in percentage:

 (*100 "FREE (%)",
 (*100 "USED (%)"
from (select sum(bytes)/1024/1024 free from dba_free_space) t1 ,
 (select sum(bytes)/1024/1024 total from dba_Data_files) t2;

To get the size of all Data files:

select sum(bytes)/1024/1024 "Data files size in MB" from dba_data_files;

To get the size of all TEMP files:

select nvl(sum(bytes),0)/1024/1024 "Temp files size in MB" from dba_temp_files;

To get the size of the on-line redo-logs:

SELECT SUM(BYTES)/1024/1024 "Redo files size in MB" FROM SYS.V_$LOG;

Total Size and free size:

select round(sum(used.bytes) / 1024 / 1024 ) || ' MB' "Database Size"
, round(free.p / 1024 / 1024) || ' MB' "Free space"
from (select bytes from v$datafile
 union all
 select bytes from v$tempfile
 union all
 select bytes from v$log) used
, (select sum(bytes) as p from dba_free_space) free
group by free.p;

Individual tablespace size:

select tablespace_name as "Tablespace Name",sum(bytes)/(1024*1024) as "Size"
from dba_data_files
 group by tablespace_name

Individual tablespace used size:

select tablespace_name as "Tablespace Name",sum(bytes)/(1024*1024) as "Used Size"
from dba_segments
 order by 1;

Individual tablespace free space:

select tablespace_name as "Tablespace Name", sum(bytes)/(1024*1024) as "Free Space"
 from dba_free_space
 group by tablespace_name
 order by 1;

Reference Links:

Sample MySQL Configuration File and Parameter Details

February 6, 2011 Leave a comment

Here is a copy of a sample MySQL configuration file and details on few main parameters:

# Example mysql config file for small systems.
# This is for a system with little memory (<= 64M) where MySQL is only used
# from time to time and it's important that the mysqld deamon
# doesn't use much resources.
# You can copy this file to
# /etc/my.cnf to set global options,
# mysql-data-dir/my.cnf to set server-specific options (in this
# installation this directory is /usr/local/mysql/var) or
# ~/.my.cnf to set user-specific options.
# One can in this file use all long options that the program supports.
# If you want to know which options a program support, run the program
# with --help option.

# The following options will be passed to all MySQL clients
#password	= your_password
port		= 3306
socket		= /tmp/mysql.sock

# Here follows entries for some specific programs

# The MySQL server
port		= 3306
socket		= /tmp/mysql.sock
set-variable	= key_buffer=128K
set-variable	= max_allowed_packet=1M
set-variable	= thread_stack=64K
set-variable	= table_cache=4
set-variable	= sort_buffer=64K
set-variable	= net_buffer_length=2K
server-id	= 1

# Uncomment the following if you want to log updates

# Uncomment the following if you are NOT using BDB tables

# Uncomment the following if you are using Innobase tables
#innodb_data_file_path = ibdata1:100M
#innodb_data_home_dir = /usr/local/mysql/var/
#innodb_log_group_home_dir = /usr/local/mysql/var/
#innodb_log_arch_dir = /usr/local/mysql/var/
#set-variable = innodb_mirrored_log_groups=1
#set-variable = innodb_log_files_in_group=3
#set-variable = innodb_log_file_size=5M
#set-variable = innodb_log_buffer_size=8M
#set-variable = innodb_buffer_pool_size=16M
#set-variable = innodb_additional_mem_pool_size=2M
#set-variable = innodb_file_io_threads=4
#set-variable = innodb_lock_wait_timeout=50

set-variable	= max_allowed_packet=16M

# Remove the next comment character if you are not familiar with SQL

set-variable	= key_buffer=8M
set-variable	= sort_buffer=8M

set-variable	= key_buffer=8M
set-variable	= sort_buffer=8M



Config file parameters:


Reference Links:

Network Troubleshooting

February 5, 2011 Leave a comment

Here are some resources to troubleshoot network issues on Linux distributions: