Now that we have put in all that up-front effort, let us look at ways of bringing the data out of MySQL and into Hadoop.
The simplest way to export data into Hadoop is to use existing command-line tools and statements. To export an entire table (or indeed an entire database), MySQL offers the
mysqldump utility. To do a more precise export, we can use a SELECT statement of the following form:
SELECT col1, col2 from table INTO OUTFILE '/tmp/out.csv' FIELDS TERMINATED by ',', LINES TERMINATED BY '\n';
Once we have an export file, we can move it into HDFS using hadoop fs -put or into Hive through the methods discussed in the previous chapter.