Mysql – Is it possible to take same copy of thesql database in another instance(periodically) in the same server

I can see mysqldump being a little pain in the neck because of transaporting data out and then in.

Let's say you are copying data from proddb to stagedb. Here is a query to create the script for lateral copying of every table:

select
concat
(
    'drop table if exists ',db2,'.',tbl,'; ',
    'create table ',db2,'.',tbl,' like ',db1,'.',tbl,'; ',
    'insert into  ',db2,'.',tbl,' select * from ',db1,'.',tbl,';'
)
from (select table_schema db1,table_name tbl
from information_schema.tables where table_schema='stack_dev') tbls,
(select 'stack_test' db2) dbname;

Just generate the script as a SQL text file and import the text file to the target server:

PROD_IP-10.1.2.20
STAG_IP=10.1.2.40
mysql -h${PROD_IP} -uusername -p --skip-column-names -A -e"select concat('drop table if exists ',db2,'.',tbl,'; ','create table ',db2,'.',tbl,' like ',db1,'.',tbl,'; ','insert into  ',db2,'.',tbl,' select * from ',db1,'.',tbl,';') from (select table_schema db1,table_name tbl from information_schema.tables where table_schema='stack_dev') tbls,(select 'stack_test' db2) dbname;" > /root/CopyFromProdToStage.sql
mysql -h${STAG_IP} -uusername -p -A < /root/CopyFromProdToStage.sql

This should work just fine for MyISAM. It should also work for InnoDB if there are no constraints. If there are constraints, you may have to disable them for the import session:

PROD_IP-10.1.2.20
STAG_IP=10.1.2.40
echo "SET FOREIGN_KEY_CHECKS=0;" > /root/CopyFromProdToStage.sql
mysql -h${PROD_IP} -uusername -p --skip-column-names -A -e"select concat('drop table if exists ',db2,'.',tbl,'; ','create table ',db2,'.',tbl,' like ',db1,'.',tbl,'; ','insert into  ',db2,'.',tbl,' select * from ',db1,'.',tbl,';') from (select table_schema db1,table_name tbl from information_schema.tables where table_schema='stack_dev') tbls,(select 'stack_test' db2) dbname;" >> /root/CopyFromProdToStage.sql
mysql -h${STAG_IP} -uusername -p -A < /root/CopyFromProdToStage.sql

UPDATE 2012-03-09 17:14 EST

I have a stored procedure that will accomplish this. Run the following only once:

DROP DATABASE IF EXISTS utility;
CREATE DATABASE utility;
DELIMITER $$
DROP PROCEDURE IF EXISTS `utility`.`CopyDB` $$
CREATE PROCEDURE `utility`.`CopyDB` (sourceDB VARCHAR(64),targetDB VARCHAR(64))
TheStoredProcedure:BEGIN

    DECLARE found_count,ndx,ndx_last INT;
    DECLARE sqlcmd VARCHAR(1024);

    SELECT COUNT(1) INTO found_count
    FROM information_schema.tables
    WHERE table_schema = sourceDB;
    IF found_count = 0 THEN
        LEAVE TheStoredProcedure;
    END IF;

    DROP TABLE IF EXISTS DBTablesToCopy;
    CREATE TABLE DBTablesToCopy
    (
        id INT NOT NULL AUTO_INCREMENT,
        src  VARCHAR(64),
        tgt  VARCHAR(64),
        tbl  VARCHAR(64),
        PRIMARY KEY (id)
    ) ENGINE=MyISAM;
    DROP TABLE IF EXISTS SQLScriptToCopyTables;
    CREATE TABLE SQLScriptToCopyTables
    (
        id INT NOT NULL AUTO_INCREMENT,
        sqltext VARCHAR(1024),
        PRIMARY KEY (id)
    ) ENGINE=MyISAM;

    INSERT INTO DBTablesToCopy (src,tgt,tbl)
    SELECT sourceDB,targetDB,table_name
    FROM information_schema.tables
    WHERE table_schema = sourceDB;

    INSERT INTO SQLScriptToCopyTables (sqltext) VALUES
    (CONCAT('DROP DATABASE IF EXISTS ',targetDB));
    INSERT INTO SQLScriptToCopyTables (sqltext) VALUES
    (CONCAT('CREATE DATABASE ',targetDB));
    SELECT MAX(id) INTO ndx_last FROM DBTablesToCopy;
    SET ndx = 0;
    WHILE ndx < ndx_last DO
        SET ndx = ndx + 1;
        INSERT INTO SQLScriptToCopyTables (sqltext)
        SELECT CONCAT('CREATE TABLE ',tgt,'.',tbl,' LIKE ',src,'.',tbl)
        FROM DBTablesToCopy WHERE id = ndx;
    END WHILE;
    SET ndx = 0;
    WHILE ndx < ndx_last DO
        SET ndx = ndx + 1;
        INSERT INTO SQLScriptToCopyTables (sqltext)
        SELECT CONCAT('INSERT INTO ',tgt,'.',tbl,' SELECT * FROM ',src,'.',tbl)
        FROM DBTablesToCopy WHERE id = ndx;
    END WHILE;

    SELECT MAX(id) INTO ndx_last FROM SQLScriptToCopyTables;
    SET ndx = 0;
    WHILE ndx < ndx_last DO
        SET ndx = ndx + 1;
        SELECT sqltext INTO @stmt FROM SQLScriptToCopyTables WHERE id = ndx;
        PREPARE s1 FROM @stmt;
        EXECUTE s1;
        DEALLOCATE PREPARE s1;
    END WHILE;

END $$
DELIMITER ;

then anytime you feel like copying stack_dev to stack_test, do this:

call utility.copydb('stack_dev','stack_test');

and that's all.

Give it a Try !!!

Please keep in mind that prior to MySQL 5.1.38, InnoDB was not designed to access multiple CPUs. You have one of two options to get MySQL to take advantage of multiple CPUs.

• OPTION 1 : Install MySQL 5.5
• OPTION 2 : Install MySQL 5.1 InnoDB Plugin

There are new options available since MySQL 5.1.38 (InnoDB Plugin Only) that is now fully available in MySQL 5.5

Rather rewrite what I wrote in past posts about this subject, please reads my past posts discussing those new settings:

• About single threaded versus multithreaded databases performance
• Possible to make MySQL use more than one core?
• Multi cores and MySQL Performance

As for tuning all other aspects of MySQL, please refer to my past post about looking into disk space management and storage engine tuning : MySQL 5.1 InnoDB Configuration / 24GB RAM - bi-xeon high load