Paginating through a large response

Paginating through a large responseedit

Using the example from the previous section, one can continue to the next page by sending back the cursor field. In the case of CSV, TSV and TXT formats, the cursor is returned in the Cursor HTTP header.

POST /_sql?format=json
{
  "cursor": "sDXF1ZXJ5QW5kRmV0Y2gBAAAAAAAAAAEWYUpOYklQMHhRUEtld3RsNnFtYU1hQQ==:BAFmBGRhdGUBZgVsaWtlcwFzB21lc3NhZ2UBZgR1c2Vy9f///w8="
}

Which looks like:

{
  "rows" : [
    ["Dan Simmons",        "Hyperion",             482,  "1989-05-26T00:00:00.000Z"],
    ["Iain M. Banks",      "Consider Phlebas",     471,  "1987-04-23T00:00:00.000Z"],
    ["Neal Stephenson",    "Snow Crash",           470,  "1992-06-01T00:00:00.000Z"],
    ["Frank Herbert",      "God Emperor of Dune",  454,  "1981-05-28T00:00:00.000Z"],
    ["Frank Herbert",      "Children of Dune",     408,  "1976-04-21T00:00:00.000Z"]
  ],
  "cursor" : "sDXF1ZXJ5QW5kRmV0Y2gBAAAAAAAAAAEWODRMaXBUaVlRN21iTlRyWHZWYUdrdw==:BAFmBmF1dGhvcgFmBG5hbWUBZgpwYWdlX2NvdW50AWYMcmVsZWFzZV9kYXRl9f///w8="
}

Note that the columns object is only part of the first page.

You’ve reached the last page when there is no cursor returned in the results. Like Elasticsearch’s scroll, SQL may keep state in Elasticsearch to support the cursor. Unlike scroll, receiving the last page is enough to guarantee that the Elasticsearch state is cleared.

To clear the state earlier, use the clear cursor API:

POST /_sql/close
{
  "cursor": "sDXF1ZXJ5QW5kRmV0Y2gBAAAAAAAAAAEWYUpOYklQMHhRUEtld3RsNnFtYU1hQQ==:BAFmBGRhdGUBZgVsaWtlcwFzB21lc3NhZ2UBZgR1c2Vy9f///w8="
}

Which will like return the

{
  "succeeded" : true
}