Teradata

The minimization of I/Os in Teradata is one of the most important goals in performance tuning. I/Os are necessary to copy data from storage to main memory. Data can only be processed if it is in the main memory.

A Column Store is basically characterized by 3 properties:

The Teradata Tutorial to support the selection of indexes How much space does the Teradata index occupy? An index can take up surprisingly much space, especially if the Teradata system does not automatically apply Block Level Compression to the index. A NUSI can then take up many times the base table's space because multivalue compression is not applied to a NUSI! On what kind of table is the index needed? Depending on the type of table, different considerations are necessary regarding how…

The bottleneck of database systems has always been accessing the data. As soon as the data is in the main memory, it can be processed.

With modern cloud databases, such as Snowflake, elasticity is always emphasized as essential. It is cited as a major difference to on-premise shared-nothing databases like Teradata.

If a zero-copy clone of a table is created, the clone uses no storage because it shared the original table's existing micro-partitions when it was cloned. Only pointers are set for the cloned table, which points to the existing table's micro partitions.

Anyone who has been dealing with Teradata for a long time knows what a primary index is. But at some point, a new term crept in with Teradata Release 15: Primary AMP Index.

In this article, I will explain the main differences in the Architecture between Teradata and Snowflake.

Often we have already reduced the size of our tables immensely using Multivalue Compression, and yet we need more space.

Have you always wondered how to use Teradata Block Level Compression and Multivalue Compression optimally? Here is the answer!

The optimizer has various access paths to choose from when creating the execution plan. Each of these access paths has certain advantages and disadvantages. In this blog post I will introduce you to the 8 most important access paths. Do not be surprised that the hash index is not included. Teradata has completely replaced the hash index by the single-table join index and recommends in the latest documentation not to use it anymore. The single table join index can do everything the hash index…

Teradata Tuning Tips. I'll show you all the tips and tricks you can use to optimally design your Teradata Data Warehouse and SQL queries!

As we saw in the example where we queried a Teradata PPI table using only the Primary Index, it was necessary to check each partition to see if it contained the Primary Index value we were looking for.

Using the command "DIAGNOSTIC HELPSTATS ON FOR SESSION" we enable an option that displays the statistics required by the optimizer at the end of each execution plan (when the EXPLAIN command is used). Below is an example:

Teradata Identity Columns: You often need a counter that is automatically generated and is unique. Identity columns are ideal for this.

Teradata Identity Columns: You often need a counter that is automatically generated and is unique. Identity columns are ideal for this.