DWHPro Insights

Insights

327 technical articles on Teradata, Snowflake, Databricks, SQL tuning and data warehouse architecture — written from production experience, not vendor decks.

Looking for a place to start? Explore the Teradata learning paths: SQL basics, tuning, operations, and migration.

Why the Same UPDATE Means Something Entirely Different in Teradata and Snowflake Popular

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At first glance, an UPDATE looks universal.In reality, it’s one of the most misleading similarities between Teradata and Snowflake.The SQL is the same, but the storage, logging, recovery, and performance mechanics are completely different. If you’re migrating from Teradata to Snowflake (or running both), understanding these differences prevents slow jobs, unnecessary costs, and avoidable outages. …

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Teradata Hybrid: Bridge or Destination?

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For many years, Teradata was the undisputed leader in large-scale data warehousing. Banks, insurers, and telcos built their most critical systems on it. Today, the market is very different. Cloud-native databases such as Snowflake, BigQuery, and Databricks have set new standards in elasticity and simplicity. The question is: what role will Teradata play in this …

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Teradata vs. Snowflake: Why GROUP BY Performance Differs at Scale

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When migrating analytical workloads from Teradata to Snowflake, one subtle but important performance factor often gets overlooked: how the two systems handle GROUP BY operations on huge tables. The SQL looks the same, but the execution engines behave differently. If you’ve relied on Teradata for years, you may be surprised by Snowflake’s behavior. GROUP BY …

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Migrating Bulk Loads from Teradata to Snowflake

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Big files, real risks, and how not to overspend Snowflake load parallelism depends on format and file options as well as file count. Qualifying large uncompressed CSV files support parallel scanning. Multiple moderately sized files can help, but one file is not universally one thread. Start with roughly 100–250 MB compressed parts as a guideline …

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Skewed Joins, Straight Answers: A Neutral Guide for Snowflake/Teradata Teams Popular

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Snowflake’s physical join execution is predominantly hash-based. In practice, you’ll observe hash-join variants with two distributions: If you come from Teradata, the intent will feel familiar: both systems aim to co-locate equal keys before matching. This article explains Snowflake’s strategies, maps them to Teradata’s (including dynamic plan fragments), and shows how to recognize and mitigate …

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Fast multi-file export of Teradata query results using only Teradata SQL Assistant Most read

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I was recently approached to support a case of importing the results of a Teradata query into a third-party vendor database. On the export side, Teradata happily wrote close to 60 million rows into a single, wide CSV file. On the other side, the import process to the target database could not cope with the …

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The Teradata AMP Worker Task Widely read

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Introduction to the Teradata AMP Worker Task The Teradata AMP Worker Task or AWT is the heart of the AMP, responsible for executing tasks and ensuring the smooth functioning of the system. AWTs are threads that process incoming tasks in the AMP. Each AMP has a finite pool of AWTs, which is shared among all …

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When Teradata Space Shortage Impacts System Performance Popular

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Running out of free Cylinders in Teradata Encountering a situation where free cylinders are exhausted is a significant concern when managing a system, and no more Teradata Space is available. It’s an issue that can adversely impact the operations and efficiency of the database, leading to potential slowdowns or even complete halts in data processing …

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