Vertica Blog

Vertica Blog

SQL

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High Availability in an EON Mode Database with Read-Only Mode

This blog is authored by Sruthi Anumula In Eon Mode, there are two major requirements for high availability: maintaining quorum and shard coverage. If either of them is lost, the whole cluster goes down. Before going into details, let us understand what quorum and shard coverage mean. Quorum: In Eon Mode, more than half of...
SQL Query Optimization

Improving COUNT DISTINCT Performance with Approximate Functions

A common analytic use case is to find the number of distinct items in a data set. Vertica performs well at solving COUNT DISTINCT in a few ways. Since Vertica stores all data in columns, it is possible to optimize for COUNT DISTINCT by building a projection that is tuned for this use case. Vertica...
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Unleash the Power of Vertica and Apache Spark Using the Upgraded Spark Connector

This post is authored by Alex Le What is Apache Spark? Apache Spark is a distributed compute engine that provides a robust API for data science, machine learning, or to work with big data. It is fast, scalable, simple, and supports multiple languages, including Python, SQL, Scala, Java, and R. Backed by the Apache 2.0...
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Going Beyond a Data Lakehouse

The way things get named in this industry can be pretty odd.  A lot of people have been hearing noise about how cool a “Data Lakehouse” is since it combines the power of a data lake with the power of a data warehouse. When I think of a lakehouse, I think of a great place...

Quick Tip: Replacing non-UTF-8 Characters

Vertica database servers expect to receive all data in UTF-8 and Vertica outputs all data in UTF-8. However, you can load or insert data into Vertica that is non UTF-8, but you'll want to clean it up. I used to recommend the REGEXP_REPLACE function for that task, but now there is a better way! Vertica...
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Quick Tip: Determining Database “Cell” Count

The Vertica system tables LICENSE_AUDITS and USER_AUDITS include a mysterious column called CELL_COUNT. What exactly is the Cell Count? It's simply a calculation that looks like this: DATABASE CELL_COUNT = (Table_1 Column Count * Table_1 Row Count) + (Table_2 Column Count * Table_2 Row Count) + … + (Table_n Column Count * Table_n Row Count)...
SQL

Quick Tip: WITH Clause Recursion

Starting with version 10.1.x, Vertica supports recursive queries. These are incredibly useful in modeling and working with self-referential hierarchical data. Let's take a look at a natural instance of this form of data: the manager-subordinate relationship. The following table contains employees (EMP_NAME), their IDs (EMP_ID), and the IDs of their managers (EMP_MGR_ID). For example, the...
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Quick Tip: Create “Super Wide” Tables

Starting in Vertica 10.1.0, you can go super wide with up to 9,800 column definitions in a table! Prior to Vertica 10.1.x, tables were limited to 1,600 columns. Example Creating a table with 9,800 columns: Hint: Try to avoid running a SELECT * FROM … a table with 9,800 columns and a trillion+ rows 😊...

List the Missing Dates in a Date Series

The TIMESERIES clause in Vertica makes it easy to list all of the gap days (that is, those that are missing) from a series of dates. Say I have this simple date series: As you can see, there are several dates missing from the series (2020-10-30, 2020-11-02, 2020-11-03 and 2020-11-04). I can list these absent...
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Getting Every Nth Row from a Table (Enhanced)

In a previous Vertica Quick Tip we learned how to query every Nth row from a table when we had a unique ID column having sequential values (that is, from a sequence). See, https://www.vertica.com/blog/vertica-quick-tip-getting-every-n-th-row-table/ What if we don’t have a key like that in our table? No problem thanks to the ROW_NUMBER() Analytic Function! Say...
Electronic medical record on digital smart device

Vertica in Good Health: Ingesting, Securing, and Analyzing Healthcare Data

Electronic Medical Records and new personal healthcare technology, particularly medical devices, generate a huge amount of data. Organizations including Cerner and Philips Healthcare rely on Vertica for data analysis. How can Vertica help you analyze this data? Vertica excels at data ingest and provides hundreds of built-in SQL and analytic functions with broad integration with...

Constellation Research Report Finds Vertica 10 a Leading Choice

A few pages into a new, detailed overview of Vertica 10, produced by Constellation Research, principle analyst Doug Henschen summarizes the top new capabilities of Vertica 10 like this: In short, the Vertica team has steadily evolved the product to keep pace with the demands of organizations that seek to do the following: Unify diverse...