Q
Problem solve Get help with specific problems with your technologies, process and projects.

# Selecting every 100th of 1,000,000 rows

How can I select every 100th record for a table of 1,000,000 rows? For example, the table consists of a distinct...

memberid, sex, and age, and I only want every 100th member from this table.

There's really no perfect way to do this with just SQL. The best solution is to use an extension to SQL like Transact-SQL (Sybase and Microsoft SQL/Server) or PL/SQL (Oracle). These language extensions allow you to write processing logic to cursor through the table, fetching every 100th row using a loop counter. This is not only the most accurate method but the most efficient as well.

If your table's memberid is an auto_increment or identity or sequence column, and if it has relatively few gaps in the numeric sequence, then you can come close to what you want with the following query --

``` select memberid, sex, age from yourtable where mod(memberid+27,100) = 0
```

Here mod() is the modulus function, which returns a remainder upon division. Check your database for the specific function name. I added 27 to the memberid simply to introduce some randomness. The query will select memberids 73, 173, 273, and so on, if they exist. Out of a million rows, this should yield ten thousand, fewer if there are gaps.

You see, a lot depends on what you want these rows for. If you need to do a strict statistical calculation, and need exactly every 100th row, you would want the first solution. If you're just interested in getting approximately one out of every hundred rows, more or less, for testing purposes, then the modulus approach will usually suffice.

Finally, a recommendation I made in a previous answer, Selecting random rows (29 May 2001):

The best solution, for situations where you only need a small number of rows, such as in testing, is to have a sample table which contains not random rows of live data, but test cases -- in other words, a place where you can collect those rows which are of interest or which represent conditions you want to test for.

This was last published in September 2002

## Content

Find more PRO+ content and other member only offers, here.

#### Have a question for an expert?

Get answers from a TechTarget expert on whatever's puzzling you.

You will be able to add details on the next page.

#### Start the conversation

Send me notifications when other members comment.

## SearchDataManagement

• ### Blockchain data disruption aborning, IDC analyst says

Blockchain data technology disruption may be in the offing. IDC's Stewart Bond says architecture at the core of controversial ...

• ### Potent NoSQL architecture engaged for building new applications

Behind hyperbolic terms like 'digital transformation' are innovative systems of engagement. DataStax CEO Billy Bosworth joins ...

• ### Finance data governance program gets new start, broader focus

Businesses constantly need to evolve their programs for governing data. Nationwide's finance data governance team shares how it ...

Most companies have data monetization opportunities they could exploit, experts say. But a clear strategy and long-term plan are ...

• ### Self-service BI and analytics tools face evolving set of challenges

Self-service BI tools have become the go-to standard for business intelligence software, but users are pushing vendors to rethink...

• ### Data science and analytics methods must balance innovation, value

In this episode of the Talking Data podcast, find out how data science teams at Cisco and LinkedIn navigate the process of doing ...

## SearchSAP

• ### SAP CEO Bill McDermott touts the intelligent enterprise

In a roundtable at SAP Ariba Live 2017, SAP CEO Bill McDermott and SAP Ariba President Alex Atzberger discuss the intelligent ...

• ### Future of Ariba Network on display at SAP Ariba Live

SAP Ariba Live shows enhancements to procurement software and looks at the future of the SAP Ariba Network, including machine ...

SAP Vora has been updated to include features that make it easier to deploy and use to get insights from Hadoop big data; SAP IBP...

## SearchSQLServer

• ### Use these commands to deploy SQL Server Docker containers

Containerized apps are everywhere, but you can also run databases in containers. Follow these commands to customize SQL Server ...

• ### Redgate tools help bring database DevOps to Visual Studio 2017

So far, data has been left out of the DevOps discussion. But DevOps for databases could grow if tools like Redgate's bundle ...

• ### Conquer real-time operational analytics in SQL Server 2016

Analytics helps improve business operations, and SQL Server 2016 users can master it -- in real time, using operational data in a...

## TheServerSide

• ### Does reading XML while writing JSON make me a bad person?

I'm always writing JSON code, loving its flexibility and forgiveness. But when I call an external service, I want to be reading ...

• ### Stop adding web UI frameworks like JSR-371 to the Java EE spec

Java EE's Servlet and JSP API provide a fine foundation for handling a web-based request-response cycle. Adding UI frameworks ...

• ### Declarative Jenkins pipeline the latest new feature in DevOps tooling

Looking to get more out of your DevOps tooling? The declarative Jenkins pipeline helps take continuous integration and continuous...

## SearchDataCenter

• ### IoT certifications land on data center admins' to-do list

IoT is still an emerging field, but data center admins should at least consider certification options to make their resume stand ...

• ### Manage and optimize IBM z Systems software costs

Some mainframe users find it tough to navigate IBM's sub-capacity pricing model. Consider tools like SCRT to more efficiently ...

• ### How hyper-converged systems change IT management

Implementing a hyper-converged infrastructure product is a big decision and one that needs to include a discussion about how ...

## SearchContentManagement

• ### How SharePoint paved the way for successful Office 365 services

SharePoint has developed many valuable enhancements through the years. However, several of those features have exceled as ...

• ### How to sort through redundancies between SharePoint and Office 365

Trying to decide between SharePoint Online and Office 365, but confused by the redundant features? Expert Scott Robinson offers ...

• ### Protecting content from the enterprise collaboration black hole

As the need for enterprise collaboration grows, so does the need for security. Organizations need to understand when confidential...

## SearchFinancialApplications

• ### Corporate wellness software can help employers reduce turnover

Data from a corporate wellness technology vendor shows that engaged employees and ones who use wellness programs are more likely ...

• ### HR analytics software boosts employee retention, lifts bottom line

With data analytics tools, HR can measure aspects such as employee engagement and turnover of staff and use the results to become...

• ### Learning management platform helps keep Unisys employees up to date

The vast majority of employees at Unisys said they were more effective at their jobs after completing training on the cloud-based...

Close