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In today's article, we will provide important insights on dead rows, vacuum operations, FSM, and VM in PostgreSQL. When performing UPDATE or DELETE operations on a table in PostgreSQL, the modified or deleted data is still retained. For example, when you execute an UPDATE operation on a table, the existing data is hidden, and a
In today's article we will be discussing how to use the "lsof" Command to list open files in Linux. In the world of Linux, understanding and managing open files is crucial for system administrators and users alike. The Linux operating system provides a powerful utility called lsof (List Open Files) that allows users to gain
In today's article, we will discuss how to change the default Tablespace in PostgreSQL. If you do not specify a different Tablespace when creating objects, PostgreSQL will, by default, create them in the pg_default Tablespace. If you want to change this, you can use the following parameter. After connecting to Postgresql; SET default_tablespace= createdTableSpaceName; Ex:
In this article, we will discuss the pmap command in Linux, which provides a detailed view of the memory usage associated with a specific process. It shows in extended format with the -x parameter. Usage of the command; pmap -x PID • First, the PID (process id) of the process must be found; $ pgrep
In today's article, we will discuss what PostgreSQL Tablespace is and why it is necessary and give an example. After creating a directory, we give permissions to the postgres user on that directory. Tablespaces in PostgreSQL allow database administrators to define locations in the file system where the files representing database objects can be stored. Once created,
In today's article, we will explain what the IPCS command in Linux is and what it is used for. ipcs shows information on the inter-process communication facilities for which the calling process has read access. By default, it shows information about all three resources: shared memory segments, message queues, and semaphore arrays. 1. The ipsc
In today's article, we will learn how to create a role with SELECT permission and add a newly created user to this role. For example, a user named Faruk was created below and a role with only select permission was created in the public schema. CREATE USER faruk with login password '1'; CREATE ROLE selectpermission;
In today's article, we will be learning how to query virtual memory status with the Free command. 1. The Free command displays the current virtual memory status of the system. $ free total used free shared buffers cached Mem: 16410752 16293944 116808 0 335432 14081932 -/+ buffers/cache: 1876580 14534172 Swap: 16779884 3353800 13426084 2. Other
In today's article, we will discuss PostgreSQL USER EXPIRE. In PostgreSQL, a password must expire to prevent a user from logging in after a specified period. This mechanism is essential for enhancing security and managing user access according to defined policies. You can increase or decrease the expiration period by +/- days for all users
In today's article, we will be explaining the "ps" command, which is the command we use to monitor running processes in Linux. 1. When run without parameters, it lists the running processes of the existing session. # ps PID TTY TIME CMD 10137 pts/5 00:00:00 ps 21871 pts/5 00:00:00 bash 2. Usage of ps command
In today's article, we will explain how to change the owner while creating or after creating a Postgresql schema. If you have created a schema in PostgreSQL but have not changed its owner, or if you want to specify a different owner while creating the schema, you can follow the steps below. To change the
In today's article, we will be learne the vmstat command, which is the system performance monitoring command in Linux. 1. if #vmstat is used without parameters, shows the virtual memory usage since the last time the system was running. # vmstat procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------ r b swpd free buff cache si so
In today's article, we will explain how to change the OWNER when creating a database and after it has been created in PostgreSQL. PostgreSQL provides an ALTER DATABASE command that allows us to modify a database. For instance, using ALTER DATABASE command, you can alter the database name, attributes, owner, etc. In Postgres, the ALTER
In this tutorial, we will learn to use the top(table of processes) command in Linux and see some practical examples. The top command shows a dynamic, real-time view of running processes and kernel-managed tasks in Linux. The command also provides a system information summary that shows resource utilization, including CPU and memory usage. Syntax top
In today's article, we will explain the PostgreSQL role authentication methods, including trust, md5, sha256, and ident on pg_hba.conf. Authentication in PostgreSQL involves the use of both pg_hba.conf and postgresql.conf. To connect a user to PostgreSQL, the system first checks the pg_hba.conf file. Based on the method defined there, authentication is performed. If authentication is
In today's article, we will learn how to Add Data File to Tablespace with queries step by step. 1. Columns and data types are learned from dba_data_files. You can learn whether dba_data_files is a view or a table as follows. In TOAD, we write dba_data_files on the editor screen and hold down Ctrl while moving
In today’s article, we will explain how to increase a tablespace in an Oracle Database after determining the sizes of the Disk Groups. When increasing the tablespace size, it is important to review the available disk space where our data files are stored. Checking the size of Disk Groups: If we are using ASM (Automatic
In today's article, we will explain how to identify the growth of the "msdb" system database, which is one of the system databases in SQL Server and may experience growth under certain circumstances. With the help of the query below, you can detect the growth in msdb and take action accordingly. USE msdb GO SELECT
In this article, we will examine the methods for granting a user access privileges to all tables in the database. 1. Log in to the database to be authorized. 2. The schemas for which authorization is requested are displayed as follows. SELECT DISTINCT OWNER FROM SYS.ALL_TABLES; 3. Schemas are selected and written to the WHERE
In today's article, we will learn how to define and get privileges such as Select, Insert, Update and Delete to specific tables in a Postgresql database. Define Privileges If you are dealing with database management, there may be times when you want to access only one view or only one table in a database. In
Sessions belonging to database statistics collection jobs can sometimes remain active. In this article, we will discuss how to identify and terminate these sessions. 1. "v$session" is queried from both nodes to find the remaining active sessions. SELECT SID, SERIAL#, USERNAME, STATUS, PROCESS FROM V$SESSION WHERE MODULE LIKE '%DBMS%'; NOTE: Sometimes this query may not
In today's article, we will be discussing the importance of seeing when SQL Server Statistics were last updated for the system. Statistics have a significant performance benefit in database systems. Queries draw their own path (execution plan) by looking at the statistics collected while they are running, and with the help of these paths, queries
In today's article, we will be learning how to Check ALERT LOG Output in Database. We can query the errors encountered in the database directly without accessing the ALERT LOG file on the server as shown below. The following query will retrieve entries from the alert log file containing "ORA-", "shutdown", and "Checkpoint not complete".
In SQL Server, we may sometimes need to check which machine has established a connection and how many connections are being made. In today's article, we will discuss how to view such parameters. For situations like this, you can use the query below. SELECT DB_NAME(database_id) as [DB] , login_name , nt_domain , nt_user_name , status
In today's article, I will be giving you information about active, inactive and other Session Statistics in the database. Active Session Statistics 1. We can collect active session statistics in the database as follows. WITH sessiondata AS (SELECT snaptime, dbtime / 1000000 dbtime, (EXTRACT(DAY FROM duration) * 86400) + (EXTRACT(HOUR FROM duration) * 3600) +
In today's article, we will cover retrieving data from MongoDB with PolyBase; PolyBase allows us to retrieve data from multiple sources and combine them into a single database. In this article, I will explain how to query a table in Mongo using polybase on SQL. If you have not created a master key, you need
In today's article, we will discuss checking for LOCKs in the database, which is one of the checks we perform when there is a problem in the database. 1. First, we check if there are any UNCOMMITTED transactions. SQL> select sysdate, t.start_time,s.sid,s.serial#,s.username,s.status,s.schemaname, s.osuser,s.process,s.machine,s.terminal,s.program,s.module,to_char(s.logon_time,'DD/MON/YY HH24:MI:SS') logon_time from v$transaction t, v$session s where s.saddr = t.ses_addr order by
In this article, we will see how to query a table in PostgreSQL by defining it as an external table in SQL Server. First, we need to introduce our user that we use on the Postgresql side to Polybase and create a credential so that we can use it later. CREATE DATABASE SCOPED CREDENTIAL postgresql_credential
This error is occurs because the statistics belonging to the External Table cannot be collected while collecting the statistics belonging to the tables. Solution: We drop the External Tables. We find the External Tables in the database as follows. The directories belonging to the SYS user are listed from TOAD. There, the external table tab
In today's article, we will be talking about What is Polybase? and how we can extract data from SQL to SQL with Polybase. Polybase is one of the auxiliary tools that SQL Server offers us. Thanks to this, we can join our tables from different sources into a single database and make queries. Some of
In today's article we will be discussing how to remove GoldenGate in Oracle. The GoldenGate application is automatically removed by following the steps below. 1. LOGIN with the GOLDENGATE user and start the GoldenGate application. # su - goldengate $ /nfs_alan/mvp_vmx/ggsci 2. Processes are STOPPED. GGSCI (mvpvmx1.hhuyanlab.local) 1> info all Program Status Group Lag at
In today's article, we will be talking about how to install Oracle GoldenGate 12.2.0.0.0. Before starting the GoldenGate installation, GRID, RDBMS and Database are installed on both SOURCE and TARGET servers. In addition, there are Schemas, Tables and data in them on the SOURCE database. After this, the steps for the GOLDENGATE installation are as
In today's article, you can use the script below to see questions such as how much RAM is used in SQL Server? How much of it is allocated. We can give max and min server memory for SQL Server's RAM usage on an instance basis, but you can use the script below to see questions
In today's article, we will be talking about the three basic commands of Oracle Enterprise Manager: Start, Status and Stop. 1. Start OEM; # emctl start dbconsole Oracle Enterprise Manager 11g Database Control Release 11.2.0.1.0 Copyright (c) 1996, 2009 Oracle Corporation. All rights reserved. https://rac3:1158/em/console/aboutApplication Starting Oracle Enterprise Manager 11g Database Control ....... started. ------------------------------------------------------------------
Today, we will discuss how you can define database-based authorizations for your user created on a database basis in PostgreSQL. Authorizations defined on a database basis are used to perform operations on objects such as tables, views, functions and procedures within the database. Authorizations on a PostgreSQL Database Basis: SELECT: Authorization defined for querying data.
In today's article, we will be covering How to Start, Stop and View the Status of Oracle Enterprise Manager. START 1. Connect to the DB from Putty and switch to the "oracle" user. 2. Initialize like OEM. -bash-3.2$ emctl start dbconsole Oracle Enterprise Manager 11g Database Control Release 11.2.0.4.0 Copyright (c) 1996, 2013 Oracle Corporation.
In this article, I will provide a practical explanation of how to Authorization to Groups in SQL Server. SQL Server offers us more than one opportunity in terms of security. SQL Server has options such as SQL Server Authentication and Windows Authentication. In addition to these, you can add clients, groups in your domain or
In today's article, we will explain step by step how to install Oracle Enterprise Manager with DBCA. 1. We open a new terminal window on the server where the operating system is located and switch to the oracle user. 2. We open the Database Configuration Assistant with the "dbca" command. 3. The Welcome screen is
In today's article, we will be discussing how to Install and Configuration SQL Server Reporting Server 2017. First, we download from the link below. https://www.microsoft.com/en-us/download/details.aspx?id=55252 After clicking Download, we download our installation file. We continue by clicking on the Install Reporting Services text. There are two options. We can continue by selecting the Evaluation version,
In this guide, we will explore the step-by-step process of migrating from MySQL to Oracle, covering key concepts, tools, and best practices to ensure a successful transition. The tool we will use for the migration process will be "Oracle SQL Developer". To give information about databases. MySQL DB 172.20.42.51 - 3306 mysql> select version(); +----------------+