How do I get metadata from Teradata?
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How do I get metadata from Teradata?
Anyways, Teradata maintains quite a detailed information about its objects (databases, tables, views, columns, datatypes etc). You can start with dbc tables like dbc. database, dbc. tables, dbc….Select statements to get metadata
- schema.
- name.
- description.
- system or user.
- columns in the table/view.
What are the different types of tables in Teradata?
Teradata – Table Types
- Derived Table.
- Volatile Table.
- Global Temporary Table.
What is a meta data table?
Metadata tables provide the data definitions for the source data that is being consumed by the operational server. These tables provide the basic information to associate the source data to the member data.
What is DBC table Teradata?
Teradata data dictionary tables are metadata tables present in the DBC database. It can be used for variety of things such as checking table size, query bottleneck and database size etc.
How do I list tables in Teradata database?
Teradata SQL Assistant for Microsoft Windows User Guide
- Select Tools > List Tables.
- Note: Wildcard characters only function when using an ODBC connection. “%” Matches zero or more characters. Note: This field does not apply to Microsoft Access databases.
How can I see tables in Teradata?
You can use SHOW TABLE to display the table definition for a PTI table. The output includes the system generated TD_TIMEBUCKET, TD_TIMECODE, and TD_SEQNO columns for PTI Tables. For complete information about SHOW TABLE syntax, see Teradata Vantage™ SQL Data Definition Language Syntax and Examples , B035-1144.
How do you create a meta data table?
To Create Metadata Tables
- In the prompt asking whether to create metadata tables, type Y and click Enter.
- Type the number corresponding to the ODBC DSN for the database to store your metadata tables and click Enter.
What is the difference between a database a table and metadata?
A database metadata consists of lots of information about its schema, storage, language, security, etc. Whereas a database schema consists of the structure of data in the database such as how the data is organized into tables, rows and columns, etc as well as the relationships and constraints between those data.
How do I list all databases in Teradata?
As @dnoeth mentioned, you can get a list of databases by querying the DBC. databasesV table. If you want to also see the hierarchy, you can see the OwnerName in that table and create the hierarchy from that parent/child relationship.
Does Teradata have schema?
Source Databases/Schemas — By default, the Source Database/Schema is the Default Database/Schema defined in the Teradata ODBC data source. This is the data source where the tables to be analyzed exist.
How will you find the table based on column name in Teradata?
To get all the column names used in database in Teradata
- select columnname from dbc. columns.
- where tablename =’tbl’
- and databasename = ‘database’
How do you get DDL of a table in Teradata?
1 Answer
- Generate DDL Statements for objects: SHOW TABLE {DatabaseB}.
- Breakdown of columns in a view: HELP VIEW {DatabaseB}.
- Alternative Solution. Would it be possible to have a stored procedure created that dynamically created the table based on the view name that is provided?
- Possible Solution – VOLATILE TABLE.
What is multiset volatile table in Teradata?
Multiset Volatile Table: A temporary multiset table that is only available to the current user in the current session. Set Volatile Table: A temporary set table that is only available to the current user in the current session.
How do I get the metadata from a table in SQL?
There are 2 simple ways:
- Option 1. sp_help ‘schema.table_name’
- Option 2. SELECT * FROM INFORMATION_SCHEMA.columns c WHERE c.table_name = ‘table_name’
How do I edit a Dataverse table?
You can edit table columns using the visual editor.
- On the left pane, select Tables.
- Select the table you want, select Edit data on the command bar to display the visual editor.
How do I create a metadata table?
Is schema same as metadata?
Metadata is ‘data about data’. Whereas Schema is the structure/layout of the system. Real world example for Metadata: The extra information generated when you take a picture with your phone such as date, location, etc. Real world example for Schema: The layout of a website such us where is the main title, content, etc.
How do I find the table schema 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 to execute multiple queries in Teradata?
Teradata enables you to check last query executed by specific user. To list sessions: List active sessions. Notes. To log query information you need to create rules for logs. To do this use BEGIN QUERY LOGGING statement. You can find out how to use it in teradata documentation. Example statement to log all queries: BEGIN QUERY LOGGING ON ALL; Query
How to optimize a Teradata query?
First of all use EXPLAIN plan to see how the query is performing.
How to check the table size using query in Teradata?
Teradata. How much space are your tables using? You can measure the space used by the tables in bytes across databases. Syntax: SELECT tablename,sum(currentperm)/1024*1024 Bytes_usage. FROM dbc.allspace. WHERE databasename=’your_database_name’. GROUP BY 1.
How to measure SQL query performance in Teradata?
Non-indexed columns used in predicates: Missing statistics force the Optimizer to do a very inaccurate heuristic estimation.
