A SELECT statement projects fields or computed values from a Fluent Bit stream or tagged event source. Its SQL-like expression is defined in a separate stream-processing configuration file and referenced by the main configuration. section 8.3
A basic statement combines:
- A selected attribute or computed expression, such as rand_value. section 8.3
- A source introduced with TAG or STREAM, such as TAG:'random-num'. section 8.3
- Optional functions and filtering, including record_tag(), sum(), count(), now(), and WHERE. section 8.3
Project a tagged field
Define a stream task with `SELECT rand_value FROM TAG:'random-num';`, configure a random input with that tag, and run Fluent Bit. The selected records appear on stdout when stdout is enabled; the demonstrated configuration initially routes other output to null. section 8.3
Listing 8.1 Query stream processor definition: query.conf
[STREAM_TASK] #1 name selectTask #2 exec SELECT rand_value FROM TAG:'random-num'; #3
View the compact stream-task configuration for the tagged-field projection. section 8.3
