Synchronizing Hudi Table Data to Hive

You can run run_hive_sync_tool.sh to synchronize data in the Hudi table to Hive.

For example, run the following command to synchronize the Hudi table in the hdfs://hacluster/tmp/huditest/hudimor1_deltastreamer_partition directory on HDFS to the Hive table table hive_sync_test3 with unite, country, and state as partition keys:

run_hive_sync_tool.sh --partitioned-by unite,country,state --base-path hdfs://hacluster/tmp/huditest/hudimor1_deltastreamer_partition --table hive_sync_test3 --partition-value-extractor org.apache.hudi.hive.MultiPartKeysValueExtractor --support-timestamp

**Table 1** Parameter description
Command	Description	Mandatory or Not (Yes or No)	Default Value
--database	Specifies the Hive database name.	No	default
--table	Specifies the Hive table name.	Yes	-
--base-file-format	Specifies the file format (PARQUET or HFILE).	No	PARQUET
--user	Specifies the Hive username.	No	-
--pass	Specifies the Hive password.	No	-
--jdbc-url	Specifies the Hive JDBC connection URL.	No	-
--base-path	Specifies the storage path of the Hudi table to be synchronized.	Yes	-
--partitioned-by	Specifies the partition key.	No	-
--partition-value-extractor	Specifies the partition class. PartitionValueExtractor needs to be implemented. The partition value can be extracted from the HDFS path.	No	SlashEncodedDayPartitionValueExtractor
--assume-date-partitioning	Creates partitions in yyyy/mm/dd format to support backward compatibility.	No	false
--use-pre-apache-input-format	Use InputFormat in the com.uber.hoodie package to replace the one in the org.apache.hudi package. Do not use this command except for migrating projects from com.uber.hoodie to org.apache.hudi.	No	false
--use-jdbc	Uses Hive JDBC connection.	No	true
--auto-create-database	Specifies whether to automatically create a Hive database.	No	true
--skip-ro-suffix	Specifies whether to skip the read-optimized view with the _ro suffix during registration.	No	false
--use-file-listing-from-metadata	Specifies whether to obtain the file list from the Hudi metadata.	No	false
--verify-metadata-file-listing	Specifies whether to verify the file list in the Hudi metadata based on the file system.	No	false
--help/-h	Specifies whether to display help information.	No	false
--support-timestamp	Specifies whether to convert TIMESTAMP_MICROS of INT64 to Hive timestamp.	No	false
--decode-partition	Specifies whether to decode the partition value if the partition is encoded during the write process.	No	false
--batch-sync-num	Specifies the number of Hive partitions to be synchronized in each batch.	No	1000

During Hive synchronization, if the table does not exist, an external table is created and partitions are added. If the table exists, check whether table schemas are different. If they are different, replace the table. Check whether new partitions exist. If new partitions exist, partitions are added accordingly.

Therefore, there are the following restrictions when Hive synchronization is used:

Fields can only be added to the schema and cannot be modified or deleted.
Partition directories can only be added but cannot be deleted.
Overwrite can only overwrite the Hudi table. The Hive table cannot be overwritten synchronously.
Do not use the timestamp type as the partition column when synchronizing a Hudi table to Hive.
When this script is used for synchronization, JDBC must be used for security purposes. That is, --use-jdbc must be set to true.