Gaurav Masand 
Open source databases such as PostgreSQL are no longer treated only as developer tools. For many enterprises, the real question has shifted from brand comfort to engineering maturity.
Steps to recover or reinstall GRUB from live media or a rescue environment.
wget is useful when you need to download files from a web directory or mirror a simple documentation page for offline use. Example This command recursively downloads the linked page and the files needed to view it locally: Options used -r or –recursive: enable recursive download. –level=1: limit recursion depth to one level. -k or … Read more
Oracle sequences generate numeric values independently of a table and are commonly used for surrogate keys, batch identifiers, and other incrementing values. Create and use a sequence CREATE SEQUENCE supplier_seq START WITH 1 INCREMENT BY 1 CACHE 20; INSERT INTO suppliers (supplier_id, supplier_name) VALUES (supplier_seq.NEXTVAL, ‘Example’); NEXTVAL gets the next value. Gaps are normal and … Read more
The SQL*Plus COPY command is a legacy way to copy query results between Oracle databases or schemas. It can still matter in older environments, but newer workflows usually use database links, CREATE TABLE AS SELECT, Data Pump, or application-level migration tools. Legacy COPY syntax COPY FROM user1/password@db1 TO user2/password@db2 CREATE destination_table USING SELECT * FROM … Read more
Oracle performance tuning starts by identifying where time is actually being spent. For SQL statements, execution plans, SQL statistics, and active-session data are usually more useful than guessing from source code. For PL/SQL, profiling tools can show which procedures or lines consume the most time. Start with SQL-level evidence Inspect the execution plan with DBMS_XPLAN. … Read more
A simple explanation of how Unix and Linux are related and where they differ.
A small LAN between Linux machines usually needs three things: working network connectivity, correct IP addressing, and a way to share or access services between machines. Check IP addresses Machines on the same LAN are usually in the same IP range, such as 192.168.1.x, depending on the router or DHCP server. Test connectivity Replace the … Read more
On modern Linux systems, the easiest and safest way to install software is usually through the distribution’s package manager. It resolves dependencies, tracks installed files, and makes updates and removal much easier than manual installs. Debian and Ubuntu sudo apt update sudo apt install package-name Fedora and RHEL-family systems sudo dnf install package-name Arch Linux … Read more
Linux can read many different file systems, but support depends on the kernel, installed packages and whether the file system was cleanly unmounted. Identify the device and file system This shows block devices, mount points and detected file system types. Create a mount point Mount read-only first Mounting read-only is safer when checking an unknown, … Read more