TABLESAMPLE
An introduction to TABLESAMPLE.
If you would like a quick look at some random set of the data in a table, you
can query it using the TABLESAMPLE keyword. As an
example, if we wanted to see a random 5% sample of the April 2017 orders we
could write a query like this:
SELECT *
FROM apr_2017_orders TABLESAMPLE(5)And the data we would get back would look something like this:
| sales_agent | account | product | order_value | create_date |
|---|---|---|---|---|
| Boris Faz | Betasoloin | GTX Plus Basic | 992 | 2017-04-03 |
| Anna Snelling | dambase | GTX Plus Pro | 5060 | 2017-04-01 |
| Reed Clapper | Bioplex | GTX Plus Pro | 5095 | 2017-04-12 |
| Violet Mclelland | Gekko & Co | MG Special | 45 | 2017-04-07 |
| Darcel Schlecht | Rundofase | MG Special | 64 | 2017-04-14 |
| Donn Cantrell | Plussunin | MG Advanced | 3655 | 2017-04-15 |
| Kary Hendrixson | Plexzap | GTX Plus Pro | 6154 | 2017-04-07 |
| Kary Hendrixson | Cheers | GTXPro | 4756 | 2017-04-12 |
| Zane Levy | Dalttechnology | GTXPro | 4168 | 2017-04-12 |
| Anna Snelling | Warephase | GTX Basic | 596 | 2017-04-08 |
| Boris Faz | Zotware | MG Special | 59 | 2017-04-15 |
| Corliss Cosme | Konex | GTX Plus Pro | 5684 | 2017-04-15 |
| Darcel Schlecht | Gogozoom | GTXPro | 4413 | 2017-04-15 |
The results returned from every TABLESAMPLE query would differ unless the query returned all of the data because every time the query was run it would select a different sample of the data to return.
Next up: Metadata Tables
An introduction to the metadata tables: Schemata, Tables, Views and Tablecolumns.