JSON Parser

Coalesce's JSON parser analyzes the structure of JSON entries within a variant column and automatically generates columns and a join that captures the different attributes within the JSON.

How to Parse JSON Data

Open up any non-source node, right-click on the variant column, and select Derive JSON mappings

Derive JSON mappings

Derive JSON mappings

Set Sample Size of JSON Parser

By default, the JSON parser captures only one record of the variant column. To scan for variation in the JSON shape across entries, the JSON parser sample size can be increased via User Menu → Org Settings → Preferences. Note: this preference is stored org-wide.

This number affects the number of rows we will attempt to scan for variances in JSON shape. Coalesce uses Snowflake's table sample to construct a sample of data. This is a sample of what is queried:

SELECT "/* variant_column_nmae */" FROM "/* fully qualified table */" SAMPLE ( /* sample size */ ROWS)


Sample Size Limit

If a user enters a sample size larger than the number of rows in the data, all the rows in the data will be scanned for structure.

JSON Parser sample size

JSON Parser sample size