[GitHub] [drill] vvysotskyi commented on a diff in pull request #2526: DRILL-8204: Allow Provided Schema for HTTP Plugin in JSON Mode

[GitBox <gi...@apache.org>]

vvysotskyi commented on code in PR #2526:
URL: https://github.com/apache/drill/pull/2526#discussion_r863046227


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contrib/storage-http/JSON_Options.md:
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+# JSON Options and Configuration 
+
+Drill has a collection of JSON configuration options to allow you to configure how Drill interprets JSON files.  These are set at the global level, however the HTTP plugin
+allows you to configure these options individually per connection and override the Drill defaults.  The options are:
+
+* `allowNanInf`:  Configures the connection to interpret `NaN` and `Inf` values
+* `allTextMode`:  By default, Drill attempts to infer data types from JSON data. If the data is malformed, Drill may throw schema change exceptions. If your data is
+  inconsistent, you can enable `allTextMode` which when true, Drill will read all JSON values as strings, rather than try to infer the data type.
+* `readNumbersAsDouble`:  By default Drill will attempt to interpret integers, floating point number types and strings.  One challenge is when data is consistent, Drill may
+  throw schema change exceptions. In addition to `allTextMode`, you can make Drill less sensitive by setting the `readNumbersAsDouble` to `true` which causes Drill to read all
+  numeric fields in JSON data as `double` data type rather than trying to distinguish between ints and doubles.
+* `enableEscapeAnyChar`:  Allows a user to escape any character with a \
+* `skipMalformedRecords`:  Allows Drill to skip malformed records and recover without throwing exceptions.
+* `skipMalformedDocument`:  Allows Drill to skip entire malformed documents without throwing errors.
+
+All of these can be set by adding the `jsonOptions` to your connection configuration as shown below:
+
+```json
+
+"jsonOptions": {
+  "allTextMode": true, 
+  "readNumbersAsDouble": true
+}
+
+```
+
+## Schema Provisioning
+One of the challenges of querying APIs is inconsistent data.  Drill allows you to provide a schema for individual endpoints.  You can do this in one of three ways: 
+
+1. By providing a schema inline [See: Specifying Schema as Table Function Parameter](https://drill.apache.org/docs/plugin-configuration-basics/#specifying-the-schema-as-table-function-parameter)
+2. By providing a schema in the configuration for the endpoint.
+3. By providing a serialized TupleMetadata of the desired schema.  This is an advanced functionality and should only be used by advanced Drill users.
+
+The schema provisioning currently supports complex types of Arrays and Maps at any nesting level.
+
+### Example Schema Provisioning:
+```json
+"jsonOptions": {
+  "providedSchema": [

Review Comment:
   Can we use fields, schema serialization, and deserialization logic from TupleMetadata? It has a good human-readable string representation that is much more compact than JSON



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