Databases

 To exclude tables when you are creating database backup from MySQL, execute below query. mysqldump -u root -p<Password> DATABASENAME --ignore-table= DATABASENAME.TABLENAME  > BACKUPFILENAME.sql  To include  tables when you are creating database backup from MySQL, execute below query. mysqldump -u root -p<Password> DATABASENAME TABLENAME1 TABLENAME2  > BACKUPFILENAME.sql Take note that there is no whitespace between -p and the password..

 When you encounter the error  ORA-28001: the password has expired, execute below queries to resolve this. export ORACLE_SID=< databaseName> sqlplus / as SYSDBA SQL>  alter profile default limit password_life_time unlimited; SQL>  alter user <userName> identified by <password>; SQL> commit; SQL>  exit;

 To set max memory for Microsoft SQL server, use the below Transact SQL. USE master EXEC sp_configure ''show advanced options'', 1 RECONFIGURE WITH OVERRIDE GO --To set a maximum memory limit, type the following, pressing Enter after each line: USE master EXEC sp_configure ''max server memory (MB)'', <MaxServerMemory> RECONFIGURE WITH OVERRIDE GO --MaxServerMemory is the value of the physical memory in megabytes (MB) that you want to allocate. --To hide the maximum memory setting, type the following, pressing Enter after each line: USE master EXEC sp_configure ''show advanced options'', 0 RECONFIGURE WITH OVERRIDE GO exit

 To get all the constraints created in Oracle database, use below query.              SELECT * FROM USER_CONSTRAINTS; If you want to get the constraints  created for a particular user then use below SQL query.              SELECT   *   FROM  USER_CONSTRAINTS where owner = 'userName';

         To alter the existing datafile in Oracle database, use below query. alter database datafile '/u01/app/oracle/oradata/XE/system.dbf' autoextend on maxsize unlimited;

       To get the number of rows in all tables in Oracle database, use this query. SELECT table_name,num_rows FROM all_tables WHERE owner = 'SCHEMA';