Vertica Blog

Vertica Blog

Vertica Blog

Vertica Quick Tip: Checking User Role Membership

This blog post was authored by Jim Knicely. The HAS_ROLE function returns a Boolean value that indicates whether a role has been assigned to a user. To create a read only user and role, do the following: Later, I can verify that I made that grant by querying the V_CATALOG.GRANTS system table: But it’s a...

Aggregate Projections

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...

Vertica Quick Tip: Increasing the Performance of a Rebalance

This blog post was authored by Jim Knicely. Before performing a rebalance, Vertica by default will query system tables to compute the size of all projections involved in the rebalance task. This query can add significant overhead to the rebalance operation! To disable this query, set the configuration parameter RebalanceQueryStorageContainers to 0. Have Fun!

Vertica Quick Tip: Expiring a User’s Password

This blog post was authored by Jim Knicely. You can expire a user's password immediately using the ALTER USER statement's PASSWORD EXPIRE parameter. By expiring a password, you can: • Force users to comply with a change to password policy. • Set a new password when a user forgets the old password. This feature also...

Vertica Quick Tip: VSQL Shortcuts to Move Faster on the Command Line

This blog post was authored by Jim Knicely. vsql is Vertica’s character-based, interactive, front-end utility that lets you type SQL statements and see the results. If you’ve typed a particularly long query in vsql then realize that you’d have a typo way back at the beginning of your code (i.e. you wrote SEELECT), instead of...

Improve the Efficiency of Mergeout on Wide Tables

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...

Vertica Quick Tip: Renaming a View

This blog post was authored by Jim Knicely. You are probably aware that you can rename a table using the ALTER TABLE … RENAME command. But you might not know that you can just as easily rename a database view using a very similar command! Have fun!
Three 3D arrows, different colors pointing in different directions

North East Database Day Conference

This blog post was authored by Eden Zik. On January 19th, Vertica engineers joined the North East database community for the North East Database Day conference organized annually at MIT, sponsored by Facebook and Microsoft and featuring Turing award winner Michael Stonebraker. The full conference program can be found here: This year Styliani Pantela...

Vertica Quick Tip: Viewing Query Error Information

This blog post was authored by Jim Knicely. The V_MONITOR.ERROR_MESSAGES system table tracks error and warning messages encountered while processing queries. If you need a bit more info, like the cursor position of a syntax error, you can query the data collector table DC_ERRORS. Have fun!

Vertica Quick Tip: Setting a Client Connection Label

This blog post was authored by Jim Knicely. When you connect to a Vertica database you can set a client connection label to help you later identify the connection. Have fun!

Vertica Customer Experience Survey

You are a valued Vertica customer and we are interested in your opinions. We want to hear about your experiences with our product, technical support, documentation, and community. Please take a few minutes to respond to our short survey and evaluate our database product here. We look forward to hearing from you!

Vertica Quick Tip: Analyzing Table Statistics by Column

This blog post was authored by Jim Knicely. The ANALYZE_STATISTICS function collects and aggregates data samples and storage information from all nodes that store projections associated with the specified table. On a very large wide table it will take a significant amount of time to gather those statistics. In many situations only a few columns...