What is DDL in Teradata?
16.10 – Data Definition Language Statements – Teradata Database.
What are the commands of DDL?
Data Definition Language (DDL) commands:
- CREATE to create a new table or database.
- ALTER for alteration.
- Truncate to delete data from the table.
- DROP to drop a table.
- RENAME to rename a table.
What is DDL and example?
DDL statements are similar to a computer programming language for defining data structures, especially database schemas. Common examples of DDL statements include CREATE, ALTER, and DROP. Today’s databases incorporate DDL in any formal language that describes data, although it is considered a subset of SQL.
What are DML and DDL commands?
DML stands for Data Manipulation Language. 2. Usage. DDL statements are used to create database, schema, constraints, users, tables etc. DML statement is used to insert, update or delete the records.
What is table lookup in Teradata?
In my Teradata SQL Assistant Client, I can right-click a table and select Show Definition, this will display the column types and how they are defined.
How would you describe a view in Teradata?
Views are database objects that are built by the query. Views can be built using a single table or multiple tables by way of join. Their definition is stored permanently in data dictionary but they don’t store copy of the data.
What is GTT in teradata?
16.10 – Global Temporary Tables – Teradata Database.
How do I find primary key in Teradata?
If you explicitly define a primary key in the table definition, teradata will maintain it with indextype = ‘K’ in the DBC. Indices view. Otherwise you are stuck to looking for unique indexes via uniquenessflag = ‘y’ in dbc.
What is temp table in Teradata?
A global temporary table has a persistent table definition that is stored in the Data Dictionary. Any number of sessions can materialize and populate their own local copies that are retained until session logoff.
How do I see indexes in Teradata?
To find the join indexes that are defined on your table, run the following query:
- SELECT * FROM dbc. indices.
- WHERE indextype=’J’
- AND databasename=’your_database_name’
- AND tablename=’your_table_name’
- ORDER BY indexname,columnposition;