Hive partitioned tables Issue with schema & PrestoDB
It's very strange for Hive and PrestoDB user that the schema of partitioned tables in Hive is defined on partition level as well. Partition level schema and table level schema in Apache Hadoop is letting complex. Let's see the details in below example: Table schema In Hive you can change the schema of an existing table. Let’s say you have a table: CREATE TABLE TEST1 (ID INT, NAME STRING, RATING INT ) ROW FORMAT DELIMITED FIELDS TERMINATED BY "\t" LINES TERMINATED BY '\n' STORED AS TEXTFILE; We will focus on the third column named rating. We load few records for hdfs to this table. The file looks like this: 1 john 3.5 2 Dav 4.6 3 andy 5 hive -e "load data inpath 'input.txt' into table test1" The third column has some decimal values, but we have defined this column as integer, so the we won’t see the decimal part in the data: hive> select * from te...