Posts Tagged ‘Query’

How to completely disable Replication in MySQL server 5.1.61 on Debian GNU / Linux

Monday, July 16th, 2012

Replication_mysql_disable

Some time ago on one of the Database MySQL servers, I've configured replication as it was required to test somethings. Eventually it turned out replication will be not used (for some reason) it was too slow and not fitting our company needs hence we needed to disable it.

It seemed logical to me that, simply removing any replication related directives from my.cnf and a restart of the SQL server will be enough to turn replication off on the Debian Linux host. Therefore I proceeded removed all replication configs from /etc/my/my.cnf and issued MySQL restart i. e.:

sql-server:~# /etc/init.d/mysql restart
....

This however didn't turned off replication,as I thought and in phpmyadminweb frontend interface, replication was still appearing to be active in the replication tab.

Something was still making the SQL server still act as an Replication Slave Host, so after a bit of pondering and trying to remember, the exact steps I took to make the replication work on the host I remembered that actually I issued:

mysql> START SLAVE;

Onwards I run:

mysql> SHOW SLAVE STATUS;
....

and found in the database the server was still running in Slave Replication mode

Hence to turn off the db host run as a Slave, I had to issue in mysql cli:

mysql> STOP SLAVE;
Query OK, 0 rows affected, 1 warning (0.01 sec)
mysql> RESET SLAVE;
Query OK, 0 rows affected, 1 warning (0.01 sec)

Then after a reload of SQL server in memory, the host finally stopped working as a Slave Replication host, e.g.

sql-server:~# /etc/init.d/mysql restart
....

After the restart, to re-assure myself the SQL server is no more set to run as MySQL replication Slave host:

mysql> SHOW SLAVE STATUS;
Empty set (0.00 sec)

Cheers 😉

Oracle: Get database, tables and instances access permissions

Thursday, January 30th, 2014

Oracle user get permissions of table database and instances access
If you are logged in to Oracle SQL server with sqlplus and you're not sure to which Database, Tables, Object instances you have permissions to below 2 queries will be of use:

SQL> SELECT DISTINCT OWNER, OBJECT_NAME  FROM ALL_OBJECTS  WHERE OBJECT_TYPE = 'TABLE';

Query lists all queries in a Oracle table schema. Alternavite shorter way to do the query is via:

SQL> SELECT table_name FROM user_tables;

SQL> SELECT * FROM TAB;

Shows your own schema's all tables and views.

Other oracle useful query is the Oracle equivalent of MySQL SHOW TABLES;

SQL> SELECT table_name FROM user_tables;

It will also output info only for logged in user credentials, if you're logged in as oracle database administrator (DBA role) account and you would like to check what Instances are owned by any user lets say user GEORGI query should be;

SQL> SELECT DISTINCT OWNER, OBJECT_NAME  FROM ALL_OBJECTS  WHERE OBJECT_TYPE = 'TABLE' AND OWNER = 'GEORGI;

Other way to do it is via:

SQL> SELECT Table_Name from All_Tables WHERE OWNER = 'YOURSCHEMA';


How to fix wordpress blog sudden redirection to present post problem

Wednesday, December 22nd, 2010

My blog’s index has suddenly started redirecting to my last post. That was rather strange, since I haven’t done anything special, all I did before the problem occured was a change in wordpress wp-admin to my latest post.

There in I changed the post Visibility from Public to Private

Right after this my blog’s home started redirecting to the blog post where the changes was made.

This was really strange, so I reverted back the changes in Post’s Publish Visibility to the default setting.
Though the change the redirect to the latest post by accessing my www.pc-freak.net/blog/ was still there.

I tried completely wiping out the post by sending it to Trash and issuing the same post again, but now things became even worser.

Accessing my blog was opening 404 not found error message . Everything seemed fine in wordpress admin and therefore I suspected the redirect is being applied from info read in my wordpress database in MySQL.

A bit of investigation prooved my guess was correct, for some reason a record was made to the MySQL blog database in table wp_redirection_items.

The incorrect redirection wihtin the database looked like so:

| 4 | /blog/ | 0 | 2 | 0 | 0000-00-00 00:00:00 | 2 | enabled | url | 301 | /blog/how-to-change-from-default-main-menu-to-other-text-in-joomla/ | url | NULL |

Removing the incorrect redirect was kind of easy and came to simply issuing:

mysql> delete from wp_redirection_items where id='3';
Query OK, 1 row affected (0.00 sec)

This fixed the redirection issue and opening my blog main page started correctly opening the main page again! 🙂