Vertica Blog
Jim Knicely with a big teddy bear

James

Vertica Field Chief Technologist

I've had the privilege of working with many database technologies in my career. But after being introduced to Vertica in May of 2011 as a client, I was hooked on the new technology after witnessing a query run in milliseconds that had previously ran for hours on the legacy database we had in place. It was then that I knew I wanted to eventually join the Vertica team, and 4 years later I did! I am currently a Vertica evangelist and am ready to help you get on board! Please feel free to reach out to me with any questions you have about Vertica and make sure to follow my Vertica Quick Tips!

Connect With James on

Helpful Tips in blue text with magnifying glass

Investigate Data Collector Table Data Produced by Scrutinize

James Knicely, Vertica Field Chief Technologist
September 5, 2019

The diagnostics tool scrutinize collects a broad range of information from a Vertica cluster. Part of the output from scrutinize includes data collector table data. Once extracted, we can easily load the data from a data collector table file into a Vertica Flex Table for analysis! Let’s take a look at the data from the...
Construction site crane building a blue SQL 3D text.

Load Data Enclosed By and Embedded With Double Quotes

James Knicely, Vertica Field Chief Technologist
September 4, 2019

Loading string data that is enclosed in double quotes where the string also contains double quotes can be problematic. We could alter the data so that it includes an escape character prior to each embedded double quote, but maybe that’s not possible. Another solution would be to use a FILLER to load the data then...
Cow peering around edge of frame with blue sky and clouds in shape of a comic book thought bubble.

Make a Cow Display Query Results in VSQL

James Knicely, Vertica Field Chief Technologist
August 19, 2019

I used to have fun with the amusing old Linux command Cowsay. It inserts any input into a word bubble and draws an ASCII cow to talk to you. You can make the cow display your query results in VSQL! Helpful Links: https://en.wikipedia.org/wiki/Cowsay https://www.vertica.com/docs/latest/HTML/Content/Authoring/ConnectingToVertica/vsql/Meta-Commands/MetaCommandReference.htm Have fun!
Business card that says Expert Tips,

Stop a Stubborn Query that Won’t Cancel

James Knicely, Vertica Field Chief Technologist
August 19, 2019

Sometimes a running SQL statement hangs and cannot be stopped using the CLOSE_SESSION or INTERRUPT_STATEMENT function. To stop it, first grab the culprit’s SESSION_ID, TRANSACTION_ID, and STATEMENT_ID from the QUERY_REQUESTS system table, then you can move it to a resource pool that has no resources! After the move and subsequent re-plan, the query will “usually”...
Compass rose with true north pointing to "Helpful Tips" text

Change Your User Password in VSQL with a Meta-Command

James Knicely, Vertica Field Chief Technologist
August 14, 2019

The \password VSQL meta-command can be used to change your database user’s password! The admin user can change the database password for any user: Helpful Link: https://www.vertica.com/docs/latest/HTML/Content/Authoring/ConnectingToVertica/vsql/Meta-Commands/MetaCommandReference.htm Have fun!
Hand holding old-fashioned brass balance scale on a black background

View the History of Connection Load Balance Operations

James Knicely, Vertica Field Chief Technologist
August 9, 2019

The Data Collector table DC_LOAD_BALANCE_OPERATIONS tracks the history of connection load balance operations. Helpful Links: https://www.vertica.com/docs/latest/HTML/Content/Authoring/AdministratorsGuide/ManagingClientConnections/LoadBalancing/ConnectionLoadBalancing.htm https://www.vertica.com/docs/latest/HTML/Content/Authoring/AdministratorsGuide/Monitoring/Vertica/RetainingMonitoringInformation.htm Have fun!
Hand holding old-fashioned brass balance scale on a black background

Load Balance Older Clients (That You Can’t Upgrade for Some Weird Reason)

James Knicely, Vertica Field Chief Technologist
August 8, 2019

Native connection load balancing is a feature built into the Vertica Analytic Database server and client libraries as well as vsql. To load balance vsql you can use the - -enable-connection-load-balance or -C command line options. In really old versions of vsql those options did not exist. How do you load balance connections from those...
Hand holding old-fashioned brass balance scale on a black background

Testing the Native Load Balancer

James Knicely, Vertica Field Chief Technologist
August 7, 2019

Native connection load balancing is a feature built into the Vertica Analytic Database server and client libraries as well as vsql. The RUN_LOAD_BALANCE_POLICY function returns a string formatted as address:port that results from running the current Native Load Balancer policy. It’s a great tool for testing after enabling a new Load Balance Policy! Because the...
Busy traffic jam

Find the Busiest Hour in the Day for I/O

James Knicely, Vertica Field Chief Technologist
August 2, 2019

The IO_USAGE system table provides disk I/O bandwidth usage history for the system. You can query it to find out interesting IO statistics like which hour of the day has the most IO usage on your Vertica cluster! Helpful Link: https://www.vertica.com/docs/latest/HTML/Content/Authoring/SQLReferenceManual/SystemTables/MONITOR/IO_USAGE.htm Have fun!
Tips and Tricks Orange Button

Theoretical Maximum Number of Rows Per Table Per Node

James Knicely, Vertica Field Chief Technologist
August 1, 2019

The Vertica Table size limit is documented to be 2^64 rows per node. Just how big is that number? That’s 18+ Sextillion rows! I’ve been tracking in a Vertica table, the number of text messages my daughter has sent/received since she first got a cell phone at the age of twelve. Now twelve years later,...
Helpful Tips message on post-it note

Restore a Single Database View from a Backup

James Knicely, Vertica Field Chief Technologist
July 29, 2019

The Vertica Backup and Recovery (vbr) utility allows you to back up and restore either the full database, or one or more schema and table objects of interest. It’s a great tool for restoring a table if someone accidentally dropped it or deleted a significant amount of data by mistake. But what about a database...
Helpful Tips text with hand and marker over data center background

Avoid 1:1 Relationships in Your Data Model

James Knicely, Vertica Field Chief Technologist
July 24, 2019

1:1 relationships exist in row-oriented databases because of performance concerns. As a columnar database, there is no reason in Vertica to separate large tables out into separate structures. That is, instead of joining two large fact tables together, combine them into a single table! Helpful Links: https://www.vertica.com/docs/latest/HTML/Content/Authoring/AnalyzingData/FlattenedTables/FlattenedTables.htm Have fun!