HTTP Protocol

Make a POST to /v1/statement with the query
The POST will require the header X-Presto-User (generally populated with username)
You get back a JSON document that might contain a nextUri link
The document will contain columns if available
The document will contain data if available
The columns field will always be set if data is set (and usually earlier)
If there is no nextUri link, then the query is finished (either successfully completed or failed)
Otherwise, keep following the nextUri link
The status field is only for displaying to humans as a hint about the query's state on the server. It is not in sync in the query state from the client's perspective and must not be used to determine whether the query is finished.
The document will contain an error field if the query has failed -- this is how you distinguish between a successfully completed query and a failed query when there is no more nextUri link
If the response is an HTTP 503, sleep 50-100ms and try again
Otherwise, if the response is anything other than an HTTP 200 with Content-Type application/json, then consider the query failed (this means something has gone wrong, for example, you might receive a 404 or 410)
The document format is exactly the same for the POST response and the nextUri link response -- you might get data immediately as a response to the POST, or it might take many requests for a longer query
SET SESSION statements
- Will return an updateType (top-level key of the returned JSON) of "SET SESSION", and a single "true" in the data list
- Will return the key-value pair in the header X-Presto-Set-Session in the format key=value
- The updateType and header may exist in the first response, or a subsequent response from a nextUri
Statements submitted following SET SESSION statements should include any key-value pairs (returned by the servers X-Presto-Set-Session) in the header X-Presto-Session. Multiple pairs can be comma-separated and included in a single header.
RESET SESSION statements
- Will return an updateType (top-level key of the returned JSON) of "RESET SESSION", and a single "true" in the data list
- Will return the session key in the header X-Presto-Clear-Session
- The updateType and header may exist in the first response, or a subsequent response from a nextUri
Statements submitted following RESET SESSION statements should no longer include any key-value pairs previously added by SET SESSION statements.
Cancel a running query with a DELETE to /v1/query/<query-id>