Import Apache Parquet Files from Amazon S3 or GCS into TiDB Cloud

You can import both uncompressed and Snappy compressed Apache Parquet format data files to TiDB Cloud. This document describes how to import Parquet files from Amazon Simple Storage Service (Amazon S3) or Google Cloud Storage (GCS) into TiDB Cloud.

Step 1. Prepare the Parquet files

1. If a Parquet file is larger than 256 MB, consider splitting it into smaller files, each with a size around 256 MB.

   TiDB Cloud supports importing very large Parquet files but performs best with multiple input files around 256 MB in size. This is because TiDB Cloud can process multiple files in parallel, which can greatly improve the import speed.

2. Name the Parquet files as follows:

   • If a Parquet file contains all data of an entire table, name the file in the ${db_name}.${table_name}.parquet format, which maps to the ${db_name}.${table_name} table when you import the data.
   • If the data of one table is separated into multiple Parquet files, append a numeric suffix to these Parquet files. For example, ${db_name}.${table_name}.000001.parquet and ${db_name}.${table_name}.000002.parquet. The numeric suffixes can be inconsecutive but must be in ascending order. You also need to add extra zeros before the number to ensure all the suffixes are in the same length.
   Note

   If you cannot update the Parquet filenames according to the preceding rules in some cases (for example, the Parquet file links are also used by your other programs), you can keep the filenames unchanged and use the Custom Pattern in Step 4 to import your source data to a single target table.

Step 2. Create the target table schemas

Because Parquet files do not contain schema information, before importing data from Parquet files into TiDB Cloud, you need to create the table schemas using either of the following methods:

• Method 1: In TiDB Cloud, create the target databases and tables for your source data.

• Method 2: In the Amazon S3 or GCS directory where the Parquet files are located, create the target table schema files for your source data as follows:

  1. Create database schema files for your source data.

     If your Parquet files follow the naming rules in Step 1, the database schema files are optional for the data import. Otherwise, the database schema files are mandatory.

     Each database schema file must be in the ${db_name}-schema-create.sql format and contain a CREATE DATABASE DDL statement. With this file, TiDB Cloud will create the ${db_name} database to store your data when you import the data.

     For example, if you create a mydb-scehma-create.sql file that contains the following statement, TiDB Cloud will create the mydb database when you import the data.

     CREATE DATABASE mydb;
     

  2. Create table schema files for your source data.

     If you do not include the table schema files in the Amazon S3 or GCS directory where the Parquet files are located, TiDB Cloud will not create the corresponding tables for you when you import the data.

     Each table schema file must be in the ${db_name}.${table_name}-schema.sql format and contain a CREATE TABLE DDL statement. With this file, TiDB Cloud will create the ${db_table} table in the ${db_name} database when you import the data.

     For example, if you create a mydb.mytable-schema.sql file that contains the following statement, TiDB Cloud will create the mytable table in the mydb database when you import the data.

     CREATE TABLE mytable (
     ID INT,
     REGION VARCHAR(20),
     COUNT INT );
     

     Note

     Each ${db_name}.${table_name}-schema.sql file should only contain a single DDL statement. If the file contains multiple DDL statements, only the first one takes effect.

Step 3. Configure cross-account access

To allow TiDB Cloud to access the Parquet files in the Amazon S3 or GCS bucket, do one of the following:

• If your Parquet files are located in Amazon S3, configure cross-account access to Amazon S3.

  Once finished, make a note of the Role ARN value as you will need it in Step 4.

• If your Parquet files are located in GCS, configure cross-account access to GCS.

Step 4. Import Parquet files to TiDB Cloud

To import the Parquet files to TiDB Cloud, take the following steps:

1. Navigate to the Clusters page.

2. Find the area of your target cluster and click Import Data in the upper-right corner of the area. The Data Import Task page is displayed.

   Tip

   Alternatively, you can also click the name of your target cluster on the Clusters page and click Import Data in the upper-right corner.

3. On the Data Import Task page, provide the following information.

   • Data Source Type: select the type of the data source.

   • Bucket URL: select the bucket URL where your Parquet files are located.

   • Data Format: select Parquet.

   • Setup Credentials (This field is visible only for AWS S3): enter the Role ARN value for Role-ARN.

   • Target Cluster: fill in the Username and Password fields.

   • DB/Tables Filter: if you want to filter which tables to be imported, you can specify one or more table filters in this field, separated by ,.

     For example:

     • db01.*: all tables in the db01 database will be imported.

     • db01.table01*,db01.table02*: all tables starting with table01 and table02 in the db01 database will be imported.

     • !db02.*: except the tables in the db02 database, all other tables will be imported. ! is used to exclude tables that do not need to be imported.

     • *.* : all tables will be imported.

       For more information, see table filter snytax.

   • Custom Pattern: enable the Custom Pattern feature if you want to import Parquet files whose filenames match a certain pattern to a single target table.

     Note

     After enabling this feature, one import task can only import data to a single table at a time. If you want to use this feature to import data into different tables, you need to import several times, each time specifying a different target table.

     When Custom Pattern is enabled, you are required to specify a custom mapping rule between Parquet files and a single target table in the following fields:

     • Object Name Pattern: enter a pattern that matches the names of the Parquet files to be imported. If you have one Parquet file only, you can enter the filename here directly.

       For example:

       • my-data?.parquet: all Parquet files starting with my-data and one character (such as my-data1.parquet and my-data2.parquet) will be imported into the same target table.
       • my-data*.parquet: all Parquet files starting with my-data will be imported into the same target table.

     • Target Table Name: enter the name of the target table in TiDB Cloud, which must be in the ${db_name}.${table_name} format. For example, mydb.mytable. Note that this field only accepts one specific table name, so wildcards are not supported.

4. Click Import.

   A warning message about the database resource consumption is displayed.

5. Click Confirm.

   TiDB Cloud starts validating whether it can access your data in the specified bucket URL. After the validation is completed and successful, the import task starts automatically. If you get the AccessDenied error, see Troubleshoot Access Denied Errors during Data Import from S3.

6. When the import progress shows success, check the number after Total Files:.

   If the number is zero, it means no data files matched the value you entered in the Object Name Pattern field. In this case, check whether there are any typos in the Object Name Pattern field and try again.

When running an import task, if any unsupported or invalid conversions are detected, TiDB Cloud terminates the import job automatically and reports an importing error.

If you get an importing error, do the following:

1. Drop the partially imported table.

2. Check the table schema file. If there are any errors, correct the table schema file.

3. Check the data types in the Parquet files.

   If the Parquet files contain any unsupported data types (for example, NEST STRUCT, ARRAY, or MAP), you need to regenerate the Parquet files using supported data types (for example, STRING).

4. Try the import task again.

Supported data types

The following table lists the supported Parquet data types that can be imported to TiDB Cloud.