Archive for

Web Server and Application Server

Web Server A Web Server can resolve (handles) HTTP request (protocol). When the web server received a HTTP request, it will return a HTTP response to clients, for example sent back a HTML page? We will further illustrate this process, when a request is sent to the Web server where came, it only simply put … Continue reading

Binding ASM Disk with Linux Multipath and Udev on SLES11 SP2

To use the Multipath and Udev, we have to understand what are they, why we want to use it. What is ‘Device Mapper Multipath’ (multipath I/O)? Device Mapper Multipath(DM-Multipath)can configure muliple I/O links between the server nodes to SAN as a single device. These I/O links might consist with various cables, switches and SCSI controllers  … Continue reading

SQL Server Co-related Query – Select the second highest

This a good example of the co-related query. For example we have table with 5 employees and their salary. If we want to query the employee with second highest salary, we can use the query below.

ORA-15055: unable to connect to ASM instance and ORA-12547: TNS:lost contact

ORA-15055: unable to connect to ASM instance and ORA-12547: TNS:lost contact After completed to installation of the Oracle RAC, I got following error when I try restart the database Check the alert log file, I found following errors Errors in file /oragi/app/oracle/diag/rdbms/rac/rac1/trace/rac1_asmb_31756.trc: Check the asm instance,the status of the asm diskgroup shows online: Check the … Continue reading

How to relocate the sys.aud$ table to another tablespace in Oracle 11g R2

When the Oracle database fail to allocate the next extent to the sys.aud$ table, all users will not able login to the database remotely. The solution of the issue is to relocate the sys.aud$ table to a dedicated tablespace and shrink the sys.aud$ table regularly. There are some reasons for DBAs to relocated the sys.aud$ … Continue reading