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Showing posts from June, 2017

MySQL mysqladmin

mysqladmin utility:-

mysqladmin is use for administrative operations. Check the server's configuration, current status and other task.

$mysqladmin [options] command [command-arg] [command [command-arg]] ...

create db_name - To create new database.

debug - Write debug information to error log.

drop db_name - Delete the database and tables.

extended-status - Display server status variables and their values.

flush-hosts - Flush all the information in host cache.

flush-logs [log_type ...] - Flush all logs.

flush-privileges - Reload the grant tables it is same as reload.

flush-status - Clear status variables

flush-tables - Flush all tables.

flush-threads - Flush the thread cache.

kill id,id,... - Kill server threads.

password new_password - Set a new password.

ping - Check whether the server is available.

processlist - Show a list of active server threads.

reload - Reload the grant tables.

refresh - Flush all tables and close and open log files.

shutdown - Stop the server.


MySQL NDB Cluster Installation for Data, SQL and Management Node

Management node: It manages the other nodes within the NDB Cluster, provides configuration data, start and stop nodes, running backups. As it manages the configuration of the other nodes, it should be started first, before any other node. Use ndb_mgmd to start it.
It also maintains a log of cluster activities. Management clients can connect to the management server and check the cluster's status.
Data node: It stores cluster data. There are as many data nodes as there are replicas, times the number of fragments. For example, with two replicas, each having two fragments, you need four data nodes. One replica is good for data storage, but no redundancy. For redundancy and high availability 2 more nodes are recommended.To start data node use ndbd or ndbmtd. Tables are normally stored completely in memory, that's why it can be refer as in-memory database. Some data can be stored on disk.
SQL node: It accesses the cluster data. It is a traditional MySQL server that uses the NDBCLUSTER…

Oracle Daily SQL

Enable System-wide tracing: alter system set events '10046 trace name context forever,level 12'; Disabled in all sessions: alter system set events '10046 trace name context off'; Session Tracing: alter session set tracefile_identifier='10046'; alter session set timed_statistics = true; alter session set statistics_level=all; alter session set max_dump_file_size = unlimited; alter session set events '10046 trace name context forever,level 12'; crsctl for Oracle RAC ./crsctl start cluster ./crsctl check crs Make column to CLOB ALTER TABLE TABLE_NAME MODIFY (COLUMN_NAME LONG); ALTER TABLE TABLE_NAME MODIFY (COLUMN_NAME CLOB); RENAME <TABLE_NAME> TO <NEW_TABLE_NAME>; Rename column, change data type, drop column: ALTER TABLE TABLE_NAME RENAME COLUMN C:OLUMN_NAME TO COLUMN_NAME1; ALTER TABLE TABLE_NAME MODIFY (COLUMN_NAME VARCHAR2(10)); ALTER TABLE TABLE_NAME DROP COLUMN COLUMN_NAME; Create Primary Key: ALTER TABLE TABLE_NAME ADD CONSTRAINT CONSTRAINT_NAME PRIMARY KEY…

Oracle Golden Gate Basic Classic

Create environment
01. Source & target - Create GG tablespace.
02. Source & target - Create the GoldenGate Schema Owner
03. Grant privilege including DBA to GG schema owner
04. Add schema owner to global parameter file ./GLOBALS
05. Execute role set up script to create role GGS_GGSUSER_ROLE
06. Grant role GGS_GGSUSER_ROLE to GG user at both Source and target
Configure GG  Extract
01. Source and Target - Configure Manager Parameters
$ ggsci
PORT 7809
02. Source, create parameter file for Extract - ex1,
EXTTRAIL /home/oracle/goldengate/dirdat/ex
TABLE <Schema>.*;
03. Source, configure Data Pump Parameters
RMTHOST <hostname>, MGRPORT 7809
RMTTRAIL /home/oracle/goldengate/dirdat/rt
TABLE <schema>.*;
Target - Create check point table
$ ggsci