How to convert an 500GB SQL table into Apache Parquet?
Apache Spark can be used to do this:
1.load your table from mysql via jdbc
2.save it as a parquet file
Example:
from pyspark.sql import SparkSession
spark = SparkSession.builder.getOrCreate()
df = spark.read.jdbc("YOUR_MYSQL_JDBC_CONN_STRING", "YOUR_TABLE",properties={"user": "YOUR_USER", "password": "YOUR_PASSWORD"})
df.write.parquet("YOUR_HDFS_FILE")
The odbc2parquet
command line tool might also be helpful in some situations.
odbc2parquet \
-vvv \ # Log output, good to know it is still doing something during large downloads
query \ # Subcommand for accessing data and storing it
--connection-string ${ODBC_CONNECTION_STRING} \
--batch-size 100000 \ # Batch size in rows
--batches-per-file 100 \ # Ommit to store entire query in a single file
out.par \ # Path to output parquet file
"SELECT * FROM YourTable"