2/2/2023 0 Comments S3 json queryThe above query using lateral join and a flatten function. , lateral flatten( input => json_data_raw:family_detail ) For example, in our case, we are interested to extract the name key and from the family_detail array object, we want to extract the name and relationship key from each JSON object. Determining what information needs to be extracted from JSON data. The next step would be to analyze the loaded raw JSON data. COPY INTO relations_json_raw from that a file format does not need to be specified because it is included in the stage definition. Now let’s copy the JSON file into relations_json_raw table. VARIANT can contain any type of data so it is suitable for loading JSON data. To load the JSON data as raw, first, create a table with a column of VARIANT type. Load JSON data as raw into temporary table CREATE OR REPLACE STAGE my_json_stage url='url of s3 bucket or azure blob with credentials'Ģ. PUT file:///home/knoldus/Desktop/family.json can also create an external stage using the AWS S3 bucket, or Microsoft Azure blob storage that contains JSON data. CREATE OR REPLACE STAGE my_json_stage file_format = (type = json) Let’s Staging JSON data file from a local file system. Staging JSON data in Snowflake is similar to staging any other files. In snowflake Staging the data means, make the data available in Snowflake stage(intermediate storage) it can be internal or external. In this blog, we will understand this approach in a step-wise manner. Snowflake has a very straight forward approach to load JSON data. If we are implementing a database solution, it is very common that we will come across a system that provides data in JSON format. The query above will return one matching record for the id passed in the query.Have you ever faced any use case or scenario where you’ve to load JSON data into the Snowflake? We better know JSON data is one of the common data format to store and exchange information between systems. If no value is specified, Amazon S3 uses a newline character (‘\n’). RecordDelimiter: The value used to separate individual records in the output. In, the example above it also has a child object with a key JSON and can be replaced with CSV when querying a CSV file. OutputSerialization: Describes the format of the data that you want Amazon S3 to return in a response. In, the example above it has a child object with a key JSON that can be replaced with CSV when querying a CSV file. InputSerialization: Describes the format of the data in the object that is being queried. S3.SelectObjectContentRequest expects these following attributesīucket: S3 Bucket name where your object isĮxpressionType: The type of the provided expression (Can be string or SQL) The s3Select function expects an object of S3.SelectObjectContentRequest type. The JSON file for this example will look like this. It performs better with compressed files because with compression the number of bytes scanned is considerably reduced and you will experience better performance with larger files when compressed.įor the purpose of this post, I am going to show one example using the JSON format and another example using a CSV format. Amazon S3 Select does not support whole-object compression for Parquet objects. Amazon S3 Select supports columnar compression for Parquet using GZIP or Snappy. GZIP and BZIP2 are the only compression formats that Amazon S3 Select supports for CSV and JSON files. GZIP or BZIP2 - CSV and JSON files can be compressed using GZIP or BZIP2. UTF-8 - UTF-8 is the only encoding type Amazon S3 Select supports You can use Amazon S3 Select to query objects that have the following format properties:ĬSV, JSON, and Parquet - Objects must be in CSV, JSON, or Parquet format By using Amazon S3 Select to filter this data, you can reduce the amount of data that Amazon S3 transfers, which reduces the cost and latency to retrieve this data. With Amazon S3 Select, you can use simple structured query language (SQL) statements to filter the contents of an Amazon S3 object and retrieve just the subset of data that you need.
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