Memory Allocation in UNIX: UNIX uses C dynamic memory allocation libraries for memory allocation. Namely malloc, realloc, calloc and free are used. Functions of these liberaries are given below. Function Description malloc allocates the specified number of bytes realloc Increases or decreases the size of the specified block of memory. Reallocates it if needed calloc allocates the specified number […]
Reduce startup and shutdown time by using warm up innodb buffer pool For database servers having large memory utilisation and have big innodb_buffer_pool_size , it takes longer to stop and start the instance. This is because more data and indexes stored in huge innodb_buffer_pool. This data and indexes are used by queries running on the […]
Few issues I came across when dealing with MySQL performance. Let us go through these problems one by one. Swap usage: MySQL loves memory as almost all databases do but MySQL tries to utilise all the possible available memory. In order to restrict MySQL to use allocated memory resources we should implement following:- Swapiness Swappiness […]
Oracle VS MySQL file architecture For Oracle database administrator, when it comes to learn new technology it always starts from comparison with respect to physical or logical architecture. Physical file architecture comparison is given below , I hope it will be very useful for Oracle or MySQL database administrators who want to learn either of […]
mysql_config_editor (utility to configure authentication information for connecting to MySQL server) Introduction: Normally we connect to MySQL using username , password , socket or host etc as shown below. bash-4.2$ mysql -uroot -p -h testmysql -S /var/log/mysql.sock Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 40974 […]
Read files using arrays in Bash script I have following file with some numeric contents in it bash-4.2$ cat /tmp/araytest.txt 1 2 3 4 5 6 7 8 9 10 11 12 13 14 If we would like save the file contents in Array. We can using following method. while read LINE do ARRAY+=(“$LINE”) done […]
Broken replication because of duplicate values MySQL 5.6 onward : In non GTID enabled replication , we use to skip duplicate errors in case of Last_Errno: 1062 . But once we enable GTID we will have to deal it differently. The procedure is to follow the following simple steps Let use assume two server A as master […]
Split Command in Unix / Linux: This utility / command in unix or linux helps to split the file into two or more files. We have multiple options to use the command as per our needs. Syntax : split [filename] [INPUT [PREFIX] ] where [filename] is the name of file we want to split. [INPUT […]
