This article provides an introduction to lookup tables along with a guide to how to create a lookup table output using Upsolver.
What are lookup tables?
Lookup tables are a key-value store for faster lookups by key (e.g. use a lookup table to get all users who clicked on a specific ad in a specific timeframe).
Lookup tables are useful for:
Join between streams
An Upsolver lookup table replaces ETL code and a serving DB like Redis or Cassandra.
When a lookup table is defined as real time, instead of waiting until the data is written to S3 and to the disk, the event’s details (the delta) are updated directly in-memory and only then stored in S3.
By querying a lookup table, it is possible to enrich one stream with data from another stream.
You can easily create a lookup table based on any of your existing data sources using one or more keys and one or more aggregations.
Aggregations are functions that group multiple events together to form a more significant result. An aggregation function can return a single value or a hash table. For example, MAX stores the maximum value for the selected stream data for each key value for the selected window period.
Unlike databases, Upsolver runs continuous queries and not ad-hoc queries. Therefore, aggregation results are incrementally updated with every incoming event.
You can also:
Apply filters to your lookup table.
These are equivalent to SQL WHERE statements.
Enrich your lookup table using calculated fields.
This enables you to transform your data using a variety of built-in formulas such as:
running a regular expression
performing a mathematical operation
extracting structured information from your raw User-Agent data
Add lookups to further enrich your lookup table.
Create a lookup table data output
1. Go to the Outputs page and click New.
2. Select Lookup Table as your output type.
3. Name your output and select your Data Sources, then click Next.
9. Through the Filters tab, add a filter like WHERE in SQL to the data source.
10. Click Make Aggregated to turn the output into an aggregated output.
Read the warning before clicking OK and then add the required aggregation.
This aggregation field will then be added to the Schema tab.
11. In the Aggregation Calculated Fields area under the Calculated Fields tab, add any required calculated fields on aggregations.
See:Functions, Aggregation Functions
Click Preview at any time to view a preview of your current output.
12. Click Run and fill out the following fields:
Query Cluster: See warning below
Cloud Storage: Where Upsolver stores the intermediate bulk files before loading
Retention: A retention period for the data in Upsolver; after this amount of time elapsed the data will be deleted forever
The default query cluster runs internal operations but does not allow external When querying from the API server, only a sample of the data is loaded.
If the data exceeds 16 MB, some keys will not return.