Google Cloud Storage (GCS)

Last updated on Jun 03, 2024

Google Cloud Storage (GCS) is a storage platform that is fast, cost-effective, secure, and used for storing unstructured data (objects) in any file format in a bucket. You can use this data for multiple processes, such as creating a BigQuery data warehouse, and running analytical processes. Hevo supports replication of data from your GCS bucket in the following file formats: AVRO, CSV, JSON, and XML.

As of Release 1.66, Hevo adds the __hevo_source_modified_at field to the Destination as a metadata field. For existing Pipelines that have this field:

  • If this field is displayed in the Schema Mapper, you must ignore it and not try to map it to a Destination table column, else the Pipeline displays an error.

  • Hevo automatically loads the information for the __hevo_source_modified_at column, which is already present in the Destination table.

You can, however, continue to use __hevo_source_modified_at to create transformations using the function event.getSourceModifiedAt(). Read Metadata Column __hevo_source_modified_at.

Example: Automatic Column Header Creation for CSV Tables

Consider the following data in CSV format, which has no column headers.

 CLAY COUNTY,32003,11973623
 CLAY COUNTY,32003,46448094
 CLAY COUNTY,32003,55206893
 CLAY COUNTY,32003,15333743
 SUWANNEE COUNTY,32060,85751490
 SUWANNEE COUNTY,32062,50972562
 ST JOHNS COUNTY,846636,32033,
 NASSAU COUNTY,32025,88310177
 NASSAU COUNTY,32041,34865452

If you disable the Treat first row as column headers option, Hevo auto-generates the column headers, as seen in the schema map below:

Column headers generated by Hevo for CSV data

The record in the Destination appears as follows:

Destination record with auto-generated column headers


  • Hevo does not consider the character used as a delimiter in CSV files as data. This is true even if you place an escape character (“\”) before the delimiter.

    For example, suppose the delimiter for your CSV file is a “;”, and the data record in your GCS Source is “A\;B”. Hevo ingests this data as two separate fields, as it does not identify the semicolon as a part of the data.

See Also

Revision History

Refer to the following table for the list of key updates made to this page:

Date Release Description of Change
May-27-2024 2.23.4 Added information about connecting to GCS with service accounts in the Configuring Google Cloud Storage as a Source section.
Mar-05-2024 2.21 Updated the ingestion frequency table in the Data Replication section.
Oct-30-2023 NA Added section, Obtaining the GCS Bucket Name and Folder Path.
Jul-25-2023 NA Added limitation about Hevo not handling escape characters in CSV files.
Jan-10-2023 NA Updated the page for consistent information structure.
Dec-20-2022 NA Added section, Limitations.
Nov-08-2022 NA Updated section, Configuring Google Cloud Storage as a Source to add information about the Convert date/time format fields to timestamp option.
Sep-21-2022 NA Added a note in section, Configuring Google Cloud Storage as a Source.
Mar-21-2022 1.85 Removed section, Limitations as Hevo now supports UTF-16 encoding format for CSV files.
Oct-25-2021 NA Added section, Data Replication.
Jun-28-2021 1.66 Updated the page overview with information about __hevo_source_modified_at being uploaded as a metadata field from Release 1.66 onwards.
Feb-22-2021 NA Added the limitation about Hevo not supporting UTF-16 encoding format for CSV data.

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