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Statistics Collection Job Remaining Active In The Database - Database Tutorials
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
SQL Server Statistics Update - Database Tutorials
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
Check Database ALERT LOG Output - Database Tutorials
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".
How To See Active Connections In SQL Server - Database Tutorials
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
Session Statistics - Database Tutorials
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) +
Retrieve Data From MongoDB With PolyBase - Database Tutorials
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
Lock Control In Database - Database Tutorials
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
Data Transfer From PostgreSQL To SQL Server With PolyBase - Database Tutorials
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
ORA-20011: Approximate NDV failed: ORA-29913: error in executing ODCIEXTTABLEOPEN callout - Database Tutorials
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
What Is PolyBase In SQL Server - Database Tutorials
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
Oracle GoldenGate Deinstall - Database Tutorials
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
Install Oracle GoldenGate 12.2.0.0.0 - Database Tutorials
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
SQL Server Usage Memory - Database Tutorials
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
Oracle Enterprise Manager Commands - Database Tutorials
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. ------------------------------------------------------------------
Database Based Authorizations In PostgreSQL - Database Tutorials
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.
How To Start And Stop Oracle Enterprise Manager - Database Tutorials
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.
Authorization To Groups In SQL Server - Database Tutorials
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
Install Oracle Enterprise Manager With DBCA - Database Tutorials
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
SQL Server Reporting Server 2017 Install And Configuration - Database Tutorials
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,
How To Migrate From MySQL To Oracle - Database Tutorials
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(); +----------------+
MSSQL Hash Partition - Database Tutorials
In this article, we will discuss the use of hash partitions to prevent slowdowns caused by large numbers of insert operations in SQL Server and to improve performance. When there is a "PAGELATCH_EX" wait type in SQL server, hash partition prevents this and produces a faster solution. Hash partition is a method generally used to
Roles In Oracle Database - Database Tutorials
In today's article, we will explain concepts such as defining roles in Oracle and which users have which roles. When you want to grant the privileges in the role to all users, they are granted as PUBLIC. CREATE ROLE HR_EMP; GRANT SELECT ON HR.EMPLOYEES TO HR_EMP; GRANT HR_EMP TO PUBLIC; As a result of this
PostgreSQL Cluster Authorization - Database Tutorials
In this article, we will learn how to authorize users created on a cluster based in PostgreSQL. When authorizing at the cluster level, if there is more than one database in the same cluster, the authorizations must be defined carefully. The authorizations granted on a cluster basis may affect other databases and database objects. LOGIN:
Materialized Views In Oracle - Database Tutorials
In today's article, we will be explaining the concept of Materialized Views in Oracle, also known as Snapshots. It is a structure that stores the data returned by a query in a table and updates this data with the main table at certain intervals. The user who will create Mview must have "CREATE MATERIALIZED VIEW"
Create A Linked Server To MySQL From SQL Server - Database Tutorials
In today's article, we will learn how to Create a Linked Server from SQL Server to MySQL. We can use the linked server feature to connect to multiple databases in MSSQL. First, we install the ODBC driver suitable for your operating system, which can be found in the link below. https://dev.mysql.com/downloads/connector/odbc/ We select the OS
Oracle Views - Database Tutorials
In this article, we will discuss the functions and types of Views in Oracle Database in detail. View is a virtual table that does not physically exist. It is stored in Oracle data dictionary and do not store any data. It can be executed when called. They are used to simplify complex SQL data and
PostgreSQL Duplicate Index Detection - Database Tutorials
In this article, we will discuss the detection and prevention of indexes created on the same columns in PostgreSQL. In this way, we can both increase query performance and prevent unnecessary disk space usage. SELECT pg_size_pretty(sum(pg_relation_size(idx))::bigint) as indexsize, (array_agg(idx))[1] as index1name, (array_agg(idx))[2] as index2name, (array_agg(idx))[3] as index3name, (array_agg(idx))[4] as index4name FROM ( SELECT indexrelid::regclass as
Partition Table – Primary Key - Database Tutorials
Global indexes become corrupted when a partition is dropped from the partition table and in this article we will learn how to fix these indexes as LOCAL indexes again. Global indexes (for example Primary Key) that exist in a partition table are corrupted and become UNUSABLE when a partition is dropped from the partition table.
Postgresql Create Index Where Condition - Database Tutorials
In this article, I will talk about how we can set conditions when creating an index in PostgreSQL. As everyone knows, when creating an index, we can create an index by giving a table name and a column name, but it takes up disk space according to the data in these columns, so what do
Add Primary Key To A Column In A Table With Data - Database Tutorials
In today's article, we will learn how to add a primary key to a column in a table containing data in an Oracle database. If we want to add a primary key to a column of a table with data and we get an error, the following process is followed. 1. We create a new
PostgreSQL Execution Plan (Explain) - Database Tutorials
In today's article, we will be talking about how to use the EXPLAIN concept and its types to understand and optimize SQL queries. In Database Systems, each query has its own Execution Plan. We can also call the Execution Plan the life cycle of that query. The Explain command helps us a lot when examining
Primary Key Creation Procedure - Database Tutorials
In today's article we will be discussing the Primary Key Creation Procedures in Oracle Database. 1. Check if there is another Primary Key with the same name. select * from dba_indexes where index_name like '%EVENT_DATA%'; 2. Parallel is given to ensure that the result occurs in a short time. alter session force parallel dml parallel
PostgreSQL Function Index - Database Tutorials
In today's article, we will learn how to use functional indexes in PostgreSQL to obtain fast access to data based on the results of function calls. For example, a common way to do case-insensitive comparisons is to use the lower function: SELECT * FROM test1 WHERE lower(col1) = 'value'; Let's continue with the indextabled1 table
Deferrable Primary Key In Oracle - Database Tutorials
In today's article, we may want it to come into play later when defining the Primary Key. For this, we will learn how to use "DEFERRABLE INITIALLY DEFERRED". But this does not mean that I will be able to add inconsistent data to the table. Yes, it can be added, but it will not be
PostgreSQL Multicolumn Indexes - Database Tutorials
In this tutorial, you will learn how to create PostgreSQL multicolumn indexes, which are indexes defined on two or more columns of a table. First, let's create our table as follows. create table indextabled1(column1 integer, column2 text, column3 boolean); After creating our table, let's load our random data as follows. insert into indextabled1(column1,column2,column3) select tt.id,
Primary Key In Oracle - Database Tutorials
In today's article, we will be explaining the concept of a primary key in Oracle, which is a single field or combination of fields that uniquely defines a record. It does not allow empty values to be entered in the relevant column and ensures that the entered value is unique. Therefore, Primary Key is the
PostgreSQL Unique Index - Database Tutorials
In this article, you will learn how to create a PostgreSQL unique index to ensure the uniqueness of values in one or more columns. When a primary key is added to a column on a table, uniqueness is also added. UNIQUE index is as follows. CREATE UNIQUE INDEX indexadi ON tabloadi (kolonadi ); Let's make
Constraints In Oracle - Database Tutorials
In today's article, we will be talking about how to use Constraints to ensure data integrity in the Oracle Database. Oracle provides us with great convenience in data integrity with PRIMARY KEY, UNIQUE KEY, FOREIGN KEY, CHECK and NOT NULL constraints. All constraints in the database can be seen in detail from the DBA_CONSTRAINTS, ALL_CONSTRAINTS
B-Tree Index In PostgreSQL - Database Tutorials
In today's article, we will discuss the B-tree index, which is a balanced tree data structure used to store indexed values in a sorted order. It is one of the most used index types in database systems. It is one of the default index types in Oracle, MSSQL and PostgreSQL. Different index types can be
Table Logging And Nologging - Database Tutorials
In today's article, we will be learning how to Logging and Nologging the Table in the Oracle database. The logging_clause lets you specify whether certain DML operations will be logged in the redo log file (LOGGING) or not (NOLOGGING). We can log while creating the table or later. Logging / nologging while creating the table;