Add create and drop materialized view SQL support

[dai-chen]

Description

Add SQL support for CREATE / DROP MATERIALIZED VIEW. To avoid dependency on entire Spark grammar file and also support any language (either SQL or PPL), the grammar rule will accept any text in AS clause.

Documentation

Please see user manual for details: https://github.com/dai-chen/opensearch-spark/blob/add-mv-syntax-with-empty-impl/docs/index.md#materialized-view

Example

spark-sql> 
CREATE MATERIALIZED VIEW http_logs_metrics
AS
SELECT
  window.start AS startTime,
  COUNT(*) AS count
FROM ds_tables.http_logs
WHERE year = 1998 AND month = 6 AND day = 11 
  AND status BETWEEN 400 AND 599
GROUP BY TUMBLE(`@timestamp`, '1 Hour')
WITH (
  auto_refresh = true,
  checkpoint_location = "s3://test/"
);

DROP MATERIALIZED VIEW http_logs_metrics

OpenSearch Index:

GET flint_myglue_default_http_logs_metrics/_mapping
{
  "flint_myglue_default_http_logs_metrics": {
    "mappings": {
      "_meta": {
        "kind": "mv",
        "indexedColumns": [
          {
            "columnType": "timestamp",
            "columnName": "startTime"
          },
          {
            "columnType": "long",
            "columnName": "count"
          }
        ],
        "name": "myglue.default.http_logs_metrics",
        "options": {
          "auto_refresh": "true",
          "checkpoint_location": "s3://test"
        },
        "source": """SELECT
  window.start AS startTime,
  COUNT(*) AS count
FROM ds_tables.http_logs
WHERE year = 1998 AND month = 6 AND day = 11
  AND status BETWEEN 400 AND 599
GROUP BY TUMBLE(`@timestamp`, '1 Hour')""",
        "version": "0.1.0",
        "properties": {}
      },
      "properties": {
        "count": {
          "type": "long"
        },
        "startTime": {
          "type": "date",
          "format": "strict_date_optional_time_nanos"
        }
      }
    }
  }
}

GET flint_myglue_default_http_logs_metrics/_search
{
    ...
    "hits": [
      {
        "_source": {
          "startTime": "1998-06-11T12:00:00.000000+0000",
          "count": 14801
        }
      },
      {
        "_source": {
          "startTime": "1998-06-11T20:00:00.000000+0000",
          "count": 9490
        }
      },
      ...

Issues Resolved

#25

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.