Home
Search results “Partition existing tables oracle”
How to Convert a Non-Partitioned Table to Partitioned using Oracle Database 12c R2
 
05:02
Oracle Database 12c Release 2 New Feature! Learn how to convert a non-partitioned table to a partitioned table - Online! This new method - using ALTER TABLE MODIFY - is much simpler than DBMS_REDEFINITION. In this free tutorial from SkillBuilders and Oracle Certified Master DBA John Watson you'll see a demonstration of converting the table and the impact on the underlying table and indexes. See all our free Oracle Database Tutorials at http://www.skillbuilders.com/free-oracle-tutorials.
Views: 3475 SkillBuilders
Oracle Optimization - Table Partitions
 
15:07
Oracle optimization: create table partitions and Index-Organized Table. Other lessons, visit http://www.learn-with-video-tutorials.com/plsql-oracle-optimization
SQL 12c Tutorial 23 : SQL Creating PARTITION on  Existing Table SQL 12c new feature
 
06:20
SQL 12c Tutorial 23 : SQL Creating PARTITION on Existing Table SQL 12c new feature SQL 12c New Features SQL 12c Tutorial for beginners Oracle SQL Tutorial for beginners Creating Partition on existing table
Views: 1356 TechLake
Partitioning in Oracle Explained with Real project Examples : Introduction
 
22:43
This Video series will explain partitioning and its use cases referencing real project examples from different domain. It will explain what when and why of partitioning in a simple but elaborate manner. This is the 1st video which explains why partitioning is required and what are the advantages we gain from it. The following videos will explain when should we do it and how.
Views: 27669 Tech Coach
Oracle Partitioning
 
18:12
Oracle Partitioning watch more videos at https://www.tutorialspoint.com/videotutorials/index.htm Lecture By: Mr. Parth Panjab, Tutorials Point India Private Limited
exchange Partition , Move partition in oracle
 
08:42
exchange Partition , Move partition in oracle Possible operations with partitions SQL Tutorial SQL Tutorial for beginners PLSQL Tutorial PLSQL Tutorial for beginners PL/SQL Tutorial PL SQL Tutorial PL SQL Tutorial for beginners PL/SQL Tutorial for beginners Oracle SQL Tutorial Add Drop Rename Split Move ( Moving from Tablespace to tablespace) Exchange (Table to Table(non Partitioned table)) not partitioned only exchanging data (p)
Views: 1516 TechLake
Oracle Tutorial || Oracle|Adv Sql | Partitioned Table Part - 1 by basha
 
33:26
DURGASOFT is INDIA's No.1 Software Training Center offers online training on various technologies like JAVA, .NET , ANDROID,HADOOP,TESTING TOOLS ,ADF,INFORMATICA,TABLEAU,IPHONE,OBIEE,ANJULAR JS, SAP... courses from Hyderabad & Bangalore -India with Real Time Experts. Mail us your requirements to [email protected] so that our Supporting Team will arrange Demo Sessions. Ph:Call +91-8885252627,+91-7207212428,+91-7207212427,+91-8096969696. http://durgasoft.com http://durgasoftonlinetraining.com https://www.facebook.com/durgasoftware http://durgajobs.com https://www.facebook.com/durgajobsinfo.......
automated oracle table partitioning
 
00:15
oracle table partitioning example
What is a LIST Partition in Oracle
 
08:07
List Partition with examples. What is LIST Partition in Oracle SQL Tutorial SQL Tutorial for beginners PLSQL Tutorial PLSQL Tutorial for beginners PL/SQL Tutorial PL SQL Tutorial PL SQL Tutorial for beginners PL/SQL Tutorial for beginners Oracle SQL Tutorial
Views: 1016 TechLake
Table Partitioning in Oracle Sql | Oracle Sql Partitioning | Oracle Sql Partitioning Step by Step
 
03:17
Table Partitioning in Oracle Sql | Oracle Sql Partitioning | Oracle Sql Partitioning Step by Step --------------------------------------------------------------------------------------------------------- oracle, partition, partitioning, sql, partitioning in oracle, hash, list, range, interval partition, reference partition, composite partition, index partition, performance, partition pruning, partition wise join, sql server, partition table, sql server table partitioning, table partitioning, sql server partitioning, sql server table partition, table partition, what is partition, partitioned table, advantages of partition, types of partitions, ,table partitioning in sql server 2012 step by step,table partitioning in sql server 2014 step by step,table partitioning in sql server 2016 step by step,partition table sql server 2012 example,sql server partition existing table,sql server partition table by month,table partitioning in sql server 2008 r2 step by step,sql server partitioning best practices,horizontal partitioning in sql server, sql tutorials for beginners, sql expert, sql expert tutorials, database, oracle, table, online training,insert into oracle,oracle insert into multiple rows,create table oracle,oracle 12c alter table add identity column,oracle create table default value sysdate,collections in oracle pl sql with examples,Oracle 12c, database, oracle database (software), sql, sql developer, sql tutorials, how to create database using dbca, how to create database in oracle,oracle cloud, database 12c, dba genesis,database services, database, create, 11g, dba, db, beginner, Please Subscribe My Channel Composite Range-Range Partitioning Composite range-range partitioning enables logical range partitioning along two dimensions; for example, partition by order_date and range subpartition by shipping_date. Composite Range-Hash Partitioning Composite range-hash partitioning partitions data using the range method, and within each partition, subpartitions it using the hash method. Composite range-hash partitioning provides the improved manageability of range partitioning and the data placement, striping, and parallelism advantages of hash partitioning. Composite Range-List Partitioning Composite range-list partitioning partitions data using the range method, and within each partition, subpartitions it using the list method. Composite range-list partitioning provides the manageability of range partitioning and the explicit control of list partitioning for the subpartitions. Composite List-Range Partitioning Composite list-range partitioning enables logical range subpartitioning within a given list partitioning strategy; for example, list partition by country_id and range subpartition by order_date. Composite List-Hash Partitioning Composite list-hash partitioning enables hash subpartitioning of a list-partitioned object; for example, to enable partition-wise joins. Composite List-List Partitioning Composite list-list partitioning enables logical list partitioning along two dimensions; for example, list partition by country_id and list subpartition by sales_channel. Composite Hash-Hash Partitioning Composite hash-hash partitioning enables hash partitioning along two dimensions. This technique is beneficial to enable partition-wise joins along two dimensions. Composite Hash-List Partitioning Composite hash-list partitioning enables hash partitioning along two dimensions. Composite Hash-Range Partitioning Composite hash-range partitioning enables hash partitioning along two dimensions.
Table Partitioning on  New table
 
05:01
Please watch complete video for more detail.
Views: 188 SqlIsEasy
Oracle Tutorial - range partition step by step part - 1
 
06:16
Hello Friends In this video i'm going to demonstrate you about ORACLE PARTITIONS, How many types of table partition in the oracle. i'm discus with you in this video, For more detail please visit on the www.ocptechnology.com
Views: 6460 OCP Technology
What is a Partition in Oracle and Type of Partitions , Range Partition
 
10:52
What is Partition in Oracle and Type of Partitions Range Partition SQL Tutorial SQL Tutorial for beginners PLSQL Tutorial PLSQL Tutorial for beginners PL/SQL Tutorial PL SQL Tutorial PL SQL Tutorial for beginners PL/SQL Tutorial for beginners Oracle SQL Tutorial
Views: 2637 TechLake
What is a Hash Partition in Oracle
 
09:07
What is a Hash Partition in Oracle SQL Tutorial SQL Tutorial for beginners PLSQL Tutorial PLSQL Tutorial for beginners PL/SQL Tutorial PL SQL Tutorial PL SQL Tutorial for beginners PL/SQL Tutorial for beginners Oracle SQL Tutorial
Views: 1085 TechLake
SQL Server Tutorial 23: Partitioning Tables and Indexes
 
07:05
How to partition a table and an index using SSMS, or T-SQL. For more info, or a copy of the scripts used in this tutorial, please email me at [email protected]
Views: 21718 Johnny Deluca
Partition Table in SQL Server
 
34:31
Create a filegroup Create a partition function Create a partition scheme Create or modify a table and specify the partition scheme as the storage location. Split Patition
Views: 662 Data Science Center
How to use partitioning to improve performance of large tables
 
42:49
In this video we cover in much more detail the improvement in performance that can be achieved by using partitioning. MS SQL server databases can scale well using this feature. We cover how partitioning a table gives similar performance as a single table with a clustered index, we then explore how adding NC index improve performance of the heap table as well as the partitioned table.
Views: 19487 Jayanth Kurup
SQL 2012 Create Partitioned Table
 
06:28
How to create a partitioned table in SQL 2012 with a partition function and partition scheme
Views: 972 DataGriff
How to view table structure in oracle database .
 
00:28
How to view table structure in oracle database .
Views: 472 latest ITChannel
Oracle Tutorial || Oracle|Adv Sql | Partitioned Table Part - 2 by basha
 
33:27
DURGASOFT is INDIA's No.1 Software Training Center offers online training on various technologies like JAVA, .NET , ANDROID,HADOOP,TESTING TOOLS ,ADF,INFORMATICA,TABLEAU,IPHONE,OBIEE,ANJULAR JS, SAP... courses from Hyderabad & Bangalore -India with Real Time Experts. Mail us your requirements to [email protected] so that our Supporting Team will arrange Demo Sessions. Ph:Call +91-8885252627,+91-7207212428,+91-7207212427,+91-8096969696. http://durgasoft.com http://durgasoftonlinetraining.com https://www.facebook.com/durgasoftware http://durgajobs.com https://www.facebook.com/durgajobsinfo......
What is the RANGE PARTITION in Oracle ?
 
14:10
Hi guys in my today scenario I'm going to explain with you What is the RANGE PARTITION in Oracle, Oracle database #RANGEPARTITIONUnbeatable,Unbreakable Platform..
Views: 7275 Oracle World
Creating range partition in Oracle 12c - Part 1
 
11:32
Partition makes a table access faster in case of very large table. In this tutorial we have tried to demonstrate the range partition on date.
Views: 188 Subhroneel Ganguly
Partitioning Enhancements in oracle 12c
 
08:33
Oracle has made 4 significant enhancements in 12c. 1.Mixing Interval and Reference partitioning 2.DDL operations on multiple partitions 3.Global Index maintenance 4.Cascade Operations from parent to child, Truncate and drop This video explains the enhancements in detail with practical examples
Views: 1924 Tech Coach
SQL Server Table Partition - Part 1
 
02:01:22
For scripts, visit www.metamanager.com SQL Server table partitioning
Views: 32593 metamanager
Composite Partitioning in Oracle
 
12:14
This video is the 6th Video in the series partitioning in oracle. It explains the different composite partitioning approaches and in what scenario they should be used with real project use case explanations.
Views: 3054 Tech Coach
Range Partitioning in Oracle
 
15:00
In this video I have explained what is range partitioning along with it's 2 real project use cases. I have also explained interval Partitioning as an extension of Range partitioning If you have not watched my Initial Videos on partitioning I will recommended watching them before watching this video Apologies for the 10 second video glitch between 6 and 7 minutes :(
Views: 5387 Tech Coach
HOW TO IDENTIFY AND DELETE DUPLICATE ROWS USING ROWID AND GROUPBY IN ORACLE SQL
 
07:53
This video demonstrates examples on how to find and delete duplicate records from a table. The video gives simple and easy to understand examples on finding duplicate records from a table using group by and having clause and row_number function. It also shows the ways in which duplicates can be deleted very efficiently using the rowid of that record. You can get the code from our website http://oracleplsqlblog.com/FullBlog/FullBlog/21
Views: 10692 Kishan Mashru
Oracle Database11g tutorials 14 : How to CREATE TABLE using sql developer and command prompt
 
08:36
Oracle Database11g tutorials 14 How to Create table using command prompt and Create table using sql developer Blog Link http://bit.ly/1TkY4Oe Time Line 0:25 Introduction of Tables in Database 1:03 What is Create Table (Introduction of create table) 1:30 Syntax of Create Table 2:08 How to create table using Command Prompt 4:55 How to create table using SQL Developer Links for Oracle Database tutorials 4: database connectivity using SQL developer and command prompt http://youtu.be/wSqoXRlXDUU You can have indepth knowledge about SQL create table here http://www.rebellionrider.com/sql-create-table.html Tool used in this tutorial is command prompt. This tutorial series is part of SQL expert exam certification training. if you are preparing for SQL certification you can use my tutorials. This SQL Tutorial is a part of free training. Copy Cloud referral link || Use this link to join copy cloud and get 20GB of free storage https://copy.com?r=j7eYO7 Contacts E-Mail [email protected] Twitter https://twitter.com/rebellionrider Instagram http://instagram.com/rebellionrider Facebook. https://www.facebook.com/imthebhardwaj Linkedin. http://in.linkedin.com/in/mannbhardwaj/ Thanks for linking, commenting, sharing and watching more of our videos This is Manish from RebellionRider.com Today in this oracle database tutorial we will see How to CREATE A TABLE. if we have to define a table in layman language then we can say that Tables are just a collection of Rows and Columns but In RDBMS tables are database objects which help in organizing data into ROWS and COLUMNS. We can also say that SQL tables are kind of data structure which are used by database for efficient storage of data. To create a table in our database we use SQL CREATE TABLE command. SQL CREATE TABLE is a type of DATA DEFINITION LANGUAGE also known as DDL. To Create a table in your schema you will require CREATE TABLE system privilege. In our future videos we will see what are system and object privileges and how to grant them to a user. Today for this video we will be using Sample schema HR which already has all the necessary privileges. Ohk Let's see the syntax. CREATE TABLE table name ( column name1 Data-Type(size), column name2 Data-Type(size), ..... ); CREATE TABLE is an oracle reserved word or say an Oracle key word whereas There are 3 different ways of creating a table in Oracle database. Creating a table using Command Line Interface (CLI) in Oracle database For demonstrating how to create table in oracle database using CLI, I'll be using Command prompt. Thats how we create table using command prompt. you can check your table structure by DESCRIBE command for that just write DESC and your table name. Like this Another way of creating a table is by using Graphic user interface (GUI) in Oracle database To demonstrate how to create table using GUI we will use SQL developer. Lets open our SQL developer I am connected to HR schema if you do not know how to create a connection to database using SQL developer please watch my oracle database tutorial 4 that explains database connectivity using SQL developer and command prompt. Link for this video is in the description below. So lets create a table. Creating a table using SQL developer is very easy we do not have to fire any query here. Let's start First of all right click on your connection in which you want to create a table and choose schema browser. This will open a separate schema browser pane or you can expend your connection by clicking this + sign and then right click on table and choose New Table. However I prefer working with schema browser so let's skip to schema browser pane here from the first drop-down list you can choose connection name and in the second drop down list you can choose what database objects you want to work with we want to create a table thus I'll choose table and then click this arrow here and choose option for new table Ok we have created a table wizard first of all give a unique name to your table and add some column as well. For this, click the green plus button. Now we already have a column so give it some name. Also choose a datatype from the list and specify any size you can check this not null column if in case you want to make this a mandatory column you can also specify default value and constraint If you want to make this column a primary key you can click here In my future video i'll show you what are these constraints and different ways of applying them on a column in a table. for this video we will concentrate on create table only so when you are done with all your columns click ok Thats your table You can double click on your table here and can see its structure. Thats it
Views: 183815 Manish Sharma
Partition Tables in SQL Server 2008 R2
 
10:20
Learn how to partition tables in SQL Server 2008 R2. Visit http://www.thomasliddledba.com for scripts used in this video.
Views: 55724 Thomas Liddle
Table Partitioning in Oracle Sql|Hash Partitioning|Range Partitioning|List Partitioning|Partitioning
 
09:04
Table Partitioning in Oracle Sql | Hash Partitioning | Range Partitioning | List Partitioning | Partitioning --------------------------------------------------------------------------------------------------------- hash partitioning,range partitioning,oracle hash partitioned index example,partition by range interval,when to use range partitioning,what is table partitioning,list partitioning,how to query partition table in oracle,partition, sql server, sql, partitioning in oracle, hash, performance, oracle, partitioning, list, range, interval partition, reference partition, composite partition, index partition, partition pruning, table partitioning, sql server table partition, table partition, hash partitioning, composite partitioning, sql server partitioning, sql server table partitioning, partition table, types of partitions, what is partition, advantages of partition, partition index, sql tutorials for beginners, sql expert, sql expert tutorials, database, oracle, table, online training,insert into oracle,oracle insert into multiple rows,create table oracle,oracle 12c alter table add identity column,oracle create table default value sysdate,collections in oracle pl sql with examples,Oracle 12c, database, oracle database (software), sql, sql developer, sql tutorials, how to create database using dbca, how to create database in oracle,oracle cloud, database 12c, dba genesis,database services, database, create, 11g, dba, db, beginner, Please Subscribe My Channel
Horizontal - Partition in SQL Server - Part 3
 
12:03
Click here to Subscribe to IT PORT Channel : https://www.youtube.com/channel/UCMjmoppveJ3mwspLKXYbVlg Horizontal partitioning divides a large table into smaller more manageable parts without having to create separate tables for each part. Data in a partitioned table is physically stored in groups of rows called partitions and each partition can be accessed and maintained separately. Partitioning is not visible to end users, a partitioned table behaves like one logical table when queried Partitioned Column : Data in a partitioned table is partitioned based on a single column, the partition column, often called the partition key. Only one column can be used as the partition column, but it is possible to use a computed column Partition Function: It defines how to partition data based on the partition column. The partition function does not explicitly define the partitions and which rows are placed in each partition Partition Scheme : It maps the logical partitions to physical file groups. It is possible to map each partition to its own file group or all partitions to one file group
Views: 365 IT Port
What is a PARTITION in Oracle? Why to use Partition And Types of Partitions
 
07:09
Hi guys in my today scenario I'm going to explain with you What is a PARTITION in Oracle? #WhatisPARTITION Why to use Partition And Types of Partitions Oracle database Unbeatable,Unbreakable Platform..
Views: 23425 Oracle World
PART 5 ADD PARTITION
 
02:35
alter table, data warehousing add partition, range partition
Views: 1065 Dr. Girija Narasimhan
Why Table Partitioning Doesn't Speed Up Query Performance
 
19:27
Learn why SQL Server's table partitioning feature doesn't make your queries faster-- and may even make them slower. In this 20 minute video, I'll show you my favorite articles, bugs, and whitepapers online to explain where table partitioning shines and why you might want to implement it, even though it won't solve your query performance problems. Articles discussed are by Gail Shaw, Remus Rusanu, and the SQL Customer Advisory Team (SQLCAT). Get URLs to each article here: http://www.littlekendra.com/2016/05/03/why-table-partitioning-doesnt-speed-up-query-performance-video/
How and Why to use 12c Release 2 Automatic List Partitioning
 
05:48
Oracle Database 12c Release 2 new feature: Automatic LIST Partitioning. Learn how and why to use this great new feature.
Views: 359 SkillBuilders
Apache Hive - 01 Partition an existing data set according to one or more partition keys
 
17:25
Connect with me or follow me at https://www.linkedin.com/in/durga0gadiraju https://www.facebook.com/itversity https://github.com/dgadiraju https://www.youtube.com/itversityin https://twitter.com/itversity
Views: 3536 itversity
Oracle Tutorial || Oracle|Adv Sql | Partitioned Table Part - 3 by basha
 
15:30
DURGASOFT is INDIA's No.1 Software Training Center offers online training on various technologies like JAVA, .NET , ANDROID,HADOOP,TESTING TOOLS ,ADF,INFORMATICA,TABLEAU,IPHONE,OBIEE,ANJULAR JS, SAP... courses from Hyderabad & Bangalore -India with Real Time Experts. Mail us your requirements to [email protected] so that our Supporting Team will arrange Demo Sessions. Ph:Call +91-8885252627,+91-7207212428,+91-7207212427,+91-8096969696. http://durgasoft.com http://durgasoftonlinetraining.com https://www.facebook.com/durgasoftware http://durgajobs.com https://www.facebook.com/durgajobsinfo......
01 Overview of table Partition in oracle
 
07:26
Partitioning enhances the performance, manageability, and availability of a wide variety of applications and helps reduce the total cost of ownership for storing large amounts of data. Partitioning allows tables, indexes, and index-organized tables to be subdivided into smaller pieces, enabling these database objects to be managed and accessed at a finer level of granularity. Oracle provides a rich variety of partitioning strategies and extensions to address every business requirement. Moreover, since it is entirely transparent, partitioning can be applied to almost any application without the need for potentially expensive and time consuming application changes. Partitioning allows a table, index, or index-organized table to be subdivided into smaller pieces, where each piece of such a database object is called a partition. Each partition has its own name, and may optionally have its own storage characteristics. From the perspective of a database administrator, a partitioned object has multiple pieces that can be managed either collectively or individually. This gives the administrator considerable flexibility in managing partitioned objects. However, from the perspective of the application, a partitioned table is identical to a non-partitioned table; no modifications are necessary when accessing a partitioned table using SQL queries and DML statements. Partitioning Key ======================== Each row in a partitioned table is unambiguously assigned to a single partition. The partitioning key is comprised of one or more columns that determine the partition where each row will be stored. Oracle automatically directs insert, update, and delete operations to the appropriate partition through the use of the partitioning key. When to Partition a Table ========================== Here are some suggestions for when to partition a table: Tables greater than 2 GB should always be considered as candidates for partitioning. Tables containing historical data, in which new data is added into the newest partition. A typical example is a historical table where only the current month's data is updatable and the other 11 months are read only. When the contents of a table need to be distributed across different types of storage devices. When to Partition an Index ============================= Here are some suggestions for when to consider partitioning an index: Avoid rebuilding the entire index when data is removed. Perform maintenance on parts of the data without invalidating the entire index. Reduce the impact of index skew caused by an index on a column with a monotonically increasing value. Partitioned Index-Organized Tables =================================== Partitioned index-organized tables are very useful for providing improved performance, manageability, and availability for index-organized tables. For partitioning an index-organized table: ============================================ Partition columns must be a subset of the primary key columns Secondary indexes can be partitioned (both locally and globally) OVERFLOW data segments are always equi-partitioned with the table partitions See Also: Oracle Database Concepts for more information about index-organized tables System Partitioning System partitioning enables application-controlled partitioning without having the database controlling the data placement. The database simply provides the ability to break down a table into partitions without knowing what the individual partitions are going to be used for. All aspects of partitioning have to be controlled by the application. For example, an insertion into a system partitioned table without the explicit specification of a partition will fail. System partitioning provides the well-known benefits of partitioning (scalability, availability, and manageability), but the partitioning and actual data placement are controlled by the application. See Also: Oracle Database Data Cartridge Developer's Guide for more information about system partitioning Partitioning for Information Lifecycle Management Information Lifecycle Management (ILM) is concerned with managing data during its lifetime. Partitioning plays a key role in ILM because it enables groups of data (that is, partitions) to be distributed across different types of storage devices and managed individually.
Views: 7317 Md Arshad
List Partitioning in Oracle
 
03:47
Understanding and creating list partition
Views: 60 Koenig Solutions
part 12 truncate partition
 
01:55
Truncate partition, alter table, data warehousing
Explain steps to perform Table Partitioning and what are the best practices to do so
 
03:18
SQL Server Interview Questions and Answers, Question for the SQL Server DBA " Explain the steps to perform Table Partitioning and best practices?" You can visit our blog http://sqlage.blogspot.com/ Twitter https://twitter.com/AamirSh48904922 Facebook https://www.facebook.com/SqlAge SQL Server DBA Interview Questions Real time SQL Server Interview Questions with Answers Experienced SQL Server Interview Questions Top 100 SQL Server DBA Interview Questions and Answers Microsoft SQL SErver DBA Interview Questions for Fresher SQL Server DBA Advanced Interview Questions and Answers
Views: 15164 TechBrothersIT
Partition Tables
 
11:26
Discussion of partition tables, including DOS and GPT tables, partition type codes, and alignment.
Views: 736 Mike Murphy
Oracle 12C New Feature - Multi Column List Partitioning
 
12:14
Oracle 12C New Feature - Multi Column List Partitioning
Views: 142 Siva Academy
Automatic List partitioning
 
08:39
Oracle 12c New Feature - Automatic List partitioning
Views: 132 Siva Academy
Installing Linux & Windows in Dual Boot: CORRECT PARTITION SCHEME & BOOT LOADER SETUP
 
16:12
In this video, I will cover two important steps of Installing Linux alongside your windows OS. 1) Choosing the correct Partition scheme 2) Setting up your Windows Boot loader to boot to Linux instead of Linux bootloader (e.g : GRUB) During a standard Linux installation, a user do not have to worry about this. But when you are trying to install Linux in separate partition, keeping your current OS, it gets little trickier. If you do not configure these two options correctly, you might end up corrupting your bootloader or previous OS installation. I will also show how you can add your Linux os option to the Windows 8 bootloader using BCDedit. This is important so that in case in future if you decide to get rid of Linux OS, your computer boots normally without any issues.
Views: 88610 XPSTECH
Delete, Drop, and Truncate Statements in Hive
 
06:41
Delete, Drop, and Truncate Statements in Hive Delete Statement: Delete statement is used to delete certain rows from a table based on a condition specified using the WHERE clause. The syntax is in below as highlighted. DELETE FROM tablename [WHERE expression]; Note: DELETE statement is available from hive 0.14.0 version and above Drop Statement: The drop table statement is used to drop the table altogether. The syntax is highlighted here: DROP TABLE IF EXISTS TABLENAME; Let’s quickly see how the managed table and external table differs when dropping the table. We have already discussed this in the “Two different types of hive tables” video. Take a look at it if you haven’t. For the managed hive tables, the drop table statement removes the metadata information as well as the data. The data will be actually moved to .Trash/Current directory. metadata will be permanently deleted. However for external tables, only the metadata information is permanently deleted and the actual data remains intact in the hdfs directories. So in the case of external table, if the table was deleted accidentally, then the table can be re-created by using the same schema and specifying the same location for the hdfs data directory. If deleting the external table was the intention, then after deleting the table using the drop statement, you may also delete the underlying hdfs data directory by issuing the hdfs dfs -rm command. Truncate Statement: Truncate table statement is used to remove only the data from the table. The table structure with the schema remains intact. Truncate removes all the rows from a table or partition. The syntax is highlighted below. TRUNCATE table syntax TRUNCATE TABLE TABLENAME;
Views: 1712 BigDataElearning