Vertica Blog

Vertica Blog

Best Practices

Aggregate Projections

Soniya Shah, Information Developer
February 27, 2018

This blog post was authored by Curtis Bennett. Vertica stores physical data for tables in objects known as projections. Unlike traditional RDBMS's, Vertica does not rely on indexes for performance. Instead, Vertica stores the physical data (either all or some of the columns) in whatever sort order is required for optimal query processing. This can...

Improve the Efficiency of Mergeout on Wide Tables

Soniya Shah, Information Developer
February 20, 2018

This blog post was co-authored by Xiao Ling and Jim Kelley. Introduction When resource pools were first introduced to Vertica, the average computer had a lot less memory than it does today. The default memory size for the Tuple Mover resource pool, 200 MB, reflects the more limited resources of that period. As hardware and...

Identifying Projection Skew

Soniya Shah, Information Developer
February 12, 2018

This blog post was authored by Curtis Bennett. In Vertica, projections can either be replicated (unsegmented), or segmented. A segmented projection divides the data up across all the nodes in your cluster. Segmentation works by hashing a key value, and then using some simple math, figuring out which node that piece of data will live...

What Projections are not Being Used

Soniya Shah, Information Developer
February 8, 2018

This blog post was authored by Eugenia Moreno. It is common to create new projections to improve performance in Vertica. However, you might forget about the old projections. Vertica still loads data in projections that you might not be using. A projection that is loaded but not picked up by the Vertica optimizer consumes storage...
Three 3D arrows, different colors pointing in different directions

Beware of Segmentation Islands

Soniya Shah, Information Developer
February 5, 2018

This blog post was authored by Curtis Bennett. Many clients who are new to Vertica are also new to big data. While Vertica’s reliance on industry-standard SQL can make the transition very easy, often the introduction of multiple nodes used in support of a database platform can take some getting used to. It is the...

Authentication Methods for dbadmin

Soniya Shah, Information Developer
January 3, 2018

This blog post was authored by Sumeet Keswani. In Vertica, when you create a new database, there are no configured authentication methods. In this case, Vertica assumes that all users, including the dbadmin, have an implicit password authentication. Users can use this authentication method both for authenticating over a network interface and for over a...

Phrase Search with Vertica Text Search

Soniya Shah, Information Developer
November 27, 2017

This blog post was authored by Serge Bonte. Vertica Text Search Vertica already provides Text Search. Text Search allows you to quickly search the contents of a single CHAR, VARCHAR, LONG VARCHAR, VARBINARY, or LONG VARBINARY field within a table to locate a specific token. Vertica implements that capability using a dedicated Text Index to...

CPU and Memory Starvation in SPREAD

Soniya Shah, Information Developer
October 12, 2017

This blog post was authored by Sumeet Keswani. What is Spread? Vertica uses an open source toolkit, Spread, to provide a high-performance control message service. Spread daemons start automatically when your database starts up for the first time. The spread daemons run on control nodes in your cluster. The control nodes manage message communication. On...

Adding Nodes to Fault Groups

Soniya Shah, Information Developer
October 9, 2017

This blog post was authored by Sarah Lemaire. Suppose you are adding new cluster nodes to your Vertica database. You want to add those nodes to particular fault groups without having to restart your Vertica database. The following steps use the example of a database with five racks and fault groups, with 9 Vertica nodes...

Building a Secure Vertica Environment

Soniya Shah, Information Developer
September 14, 2017

This blog post was authored by Soniya Shah. Vertica has a client-server architecture system, where applications that reside on the client access the Vertica cluster through drivers including ODBC, JDBC, OLEDB and ADO.NET. This post discusses secure client to server communications, authenticating access to Vertica, and administrator access. Method Vertica Options Authentication: Validate user credentials...

MERGE Statement with Filters

Soniya Shah, Information Developer
August 23, 2017

This blog post was authored by Soniya Shah. Vertica 8.1 introduced new functionality for the MERGE statement. In this post, we discuss new functionality for MERGE that allows users to filter conditions on INSERT and UPDATE clauses in a MERGE statement. The MERGE operation allows users to join the target table on another table, a...

Configuring tcp Idle Settings for Long Running Idle Sessions

Soniya Shah, Information Developer
August 14, 2017

This blog post was authored by Soniya Shah. Important: For all recommendations to changing setting values, you must change the settings on all nodes in the cluster. It is not advisable to have different settings on different nodes. Have you ever encountered one of the following types of errors? With each of these errors, the...