Category Archive: TD Tips

Mar 22

Query to find user access and roles in Teradata

Teradata developers have to face the scenarios where they need to check whether their user id (or someone else in their team) has access to particular database or table in Teradata. For this trivial question, it’s not wise to disturb the admin/DBA team if you can check it yourself by querying on just 2 DBC tables. …

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Jan 11

Teradata Tech Associates

Greetings from www.teradatatech.com !!! We at TeradataTech are looking for professionals who are interested in technical work related with Teradata, data warehouse and other relevant technologies. Approximate of 3-4 hours on weekends or 1-2 hours on weekday effort is required based on your preference. Currently we have multiple requirements like – Technical blog writers in …

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Nov 04

Recursive Query in Teradata

Guest Post  Author – Saurabh Gupta In this post we will go through recursive query with one example. The recursive query features enables to query hierarchical data such as an organisation chart or bill of materials ( check the raw materials used to make a product ). Using Recursive query data with in the single table can be …

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Oct 10

ROLLUP Function with Example

Guest Post  Author – Saurabh Gupta   In this post we will go through ROLLUP function which is one of the Extended grouping function. ROLLUP is used to aggregate data along all the levels of hierarchy within a single dimension. For example –  In time dimension data can be aggregated along different levels like day, week, month and …

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May 11

What is a pseudo table Lock in Explain Plan?

When you want to retrieve the rows from the table, the very first step in explain plan is the pseudo table lock on that table e.g – Type select * from <databasename>.<tablename> in the SQL assistant, and do the explain plan for this table. The very first step you see is – 1) First, we lock …

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Apr 21

SET or MULTISET tables

We know that in Teradata all the tables are either SET or MULTISET. The difference between SET and MULTISET tables is –  SET tables – SET tables did not allow duplicate values in the table. e.g. COLUMN 1          COLUMN 2          COLUMN 3          COLUMN 4 A                            b                            c                            d H                           g                            y                            k A             …

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Feb 24

Collision or Synonym in Teradata

Teradata is consistent with hashing a value. It means that when Teradata hashes the Index value (e.g. ‘teradatatech’) it will come up with a Row Hash. Now if Teradata hashes the same index value (‘teradatatech’) million times it will always come up with the same Row Hash. Teradata always hashes the same value with consistent …

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