Programming guide
relix explain
Prints the physical plan of each query: how the engine would run it.
Usage
relix explain [OPTIONS] [SCRIPT...]Arguments
| Argument | Description |
|---|---|
SCRIPT... | Script files, each run in a session of its own; - is standard input. With neither -e nor SCRIPT, standard input is read when it is not a terminal. |
Options
| Option | Description |
|---|---|
-e, --expr=TEXT | Relix text to run. Repeatable: the texts are one script, in order. A bare relational expression runs as a query. |
-i, --input=NAME=[FORMAT:]LOCATION | Bind the relation NAME to a file, an http(s) URL (with --remote), or - for standard input. FORMAT is csv, tsv, json or ndjson; without it the extension decides, and standard input must name one. Repeatable. |
--schema=NAME={...} | The heading of the input NAME, such as NAME='{ id: NUMBER, name: STRING }', instead of inferring one. |
--infer-rows=N | Infer an input's heading from its first N records (default: 1000). |
--unbounded=NAME | The input NAME never ends, as tail -f's does: its rows stream as they arrive, and a query that would have to read all of it first is refused. Repeatable. |
--json | Write one JSON object per query, {"script", "query", "plan"}, one per line. |
--query=NAME | Explain only the query NAME. |
It also takes the global options.
Examples
relix explain -e 'GROUP city, COUNT(*) -> n (Customers JOIN Orders)'Aggregate
└─ Join NATURAL/HASH build=RIGHT
├─ Scan Customers
└─ Scan Orders--json writes each query's plan as a JSON object instead:
relix explain --json -e 'SELECT amount > 100 (Orders)' | jq -c 'keys'["plan","query","script"]