Recover/Reinstall grub bootloader

To recover the boot loader for Ubuntu Linux or any other linux after the boot loader has been erased due to a dual windows installation or some other reason.
We need a bootable CD or USB to boot into a Linux shell.
Once looged in a Linux shell on the same machine, these steps are to be followed.
1. mount the / (root) partition of the Linux installation for which the grub boot loader has to be resintalled.
2. chroot into the Linux environment
3. run grub-installation

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NMap tutorial for beginners-part 2     It’s assumed that you are root. Many options won’t work or better to say will switch to other…

Adding sequence to a table

This TIP can be used to add a sequence in a column for a table The syntax for creating a sequence is  CREATE SEQUENCE sequence_name    MINVALUE…

Oracle SQL tuning- Identifying bottlenecks

    To start with PL/SQL or SQL tuning the first step should be to identify the bottleneck in the whole code. Idetifying individual SQL queries that are giving problems is no difficult task.
But identifying some PL/SQL block can be a difficult job.

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