1. Why Impala¶

flexibliity for your big data flow high-performance analytics exploratory business intelligence

extrac-transform-load(ETL) BI: Business intelligence

2. Getting Up and Running with Impala¶

Cloudera live demo

A view is an alias for a longer query, and takes no time or storage to set up

OLTP-style(online transaction processing)

impala implements SQL-92 standard features for queries, with som enhancements from later SQL standards Hadoop Distributed File System(HDFS)

Impala currently doesn’t have OLTP-style data manipulation language (DML) such as DELETE or UPDATE.
Impala also does not have indexes, constraints or foreign keys.
No transactions

impala can very effeciently perform full table scans of large tables.

HDFS Storage Model: CDH: Cloudera Distribution with Hadoop Parquet File Format: binary file format

ETL(Extract-trnasform-load)

Make sure always close query handles when finished(release memory) JDBC or ODBC

with Impala, the biggest I/O savings com from using partitioned tables and choosing the most appropriate file format

Impala partitioned tables are just HDFS directories UDF(user defined functions)