Cloudera’s Impala<\/h2>\n<\/div>\n<\/div>\n

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Impala was the first to bring SQL querying to the public in April 2013. Impala comes with a bunch of interesting features:<\/div>\n<\/div>\n

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• Impala can query many file format such as Parquet, Avro, Text, RCFile, SequenceFile<\/li>\n
• Impala supports data stored in HDFS, Apache HBase and Amazon S3<\/li>\n
• Impala supports multiple compression codecs:\n
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  • Snappy<\/b>\u00a0(Recommended for its effective balance between compression ratio and decompression speed),<\/li>\n
  • Gzip\u00a0<\/b>(Recommended when achieving the highest level of compression),<\/li>\n
  • Deflate\u00a0<\/b>(not supported for text files), Bzip2, LZO (for text files only);<\/li>\n<\/ul>\n<\/li>\n
  • Impala provides security through authorization based on Sentry (OS user ID)\n
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    • Defining which users are allowed to access which resources,<\/li>\n
    • What operations are they allowed to perform authentication based on Kerberos + ability to specify Active Directory username\/password,<\/li>\n
    • How does Impala verify the identity of the users to confirm that they are allowed exercise their privileges assigned to that user auditing,<\/li>\n
    • What operations were attempted,<\/li>\n
    • Did they succeed or not, allowing to track down suspicious activity; audit data are collected by Cloudera Manager;<\/li>\n<\/ul>\n<\/li>\n
    • Impala supports SSL network encryption between Impala and client programs, and between the Impala-related daemons running on different nodes in the cluster;<\/li>\n
    • Impala allows to use UDFs and UDAFs;<\/li>\n
    • Impala orders the joins\u00a0<\/b>automatically to be the most efficient;<\/li>\n
    • Impala allows admission control<\/b>\u00a0\u2013 prioritization and queueing of queries within impala;<\/li>\n
    • Impala allows multi-user concurrent queries;<\/li>\n
    • Impala caches frequently accessed data<\/b>\u00a0in memory;<\/li>\n
    • Impala computes statistics (with COMPUTE STATS);<\/li>\n
    • Impala provides window functions\u00a0(aggregation OVER PARTITION, RANK, LEAD, LAG, NTILE, and so on)\u00a0<\/b>\u2013 to provide more advanced SQL analytic capabilities (since version 2.0);<\/li>\n
    • Impala allows external joins<\/b>\u00a0and aggregation using disk (since version 2.0) \u2013 enables operations to spill to disk if their internal state exceeds the aggregate memory size;<\/li>\n
    • Impala allows subqueries<\/b>\u00a0inside WHERE clauses;<\/li>\n
    • Impala allows incremental statistics\u00a0<\/b>\u2013 only run statistics on the new or changed data for even faster statistics computations;<\/li>\n
    • Impala enables queries on complex nested structures<\/b>\u00a0including maps, structs and arrays;<\/li>\n
    • Impala enables merging (MERGE)\u00a0<\/b>in updates into existing tables;<\/li>\n
    • Impala enables some OLAP functions<\/b>\u00a0(ROLLUP, CUBE, GROUPING SET);<\/li>\n
    • Impala allows use of impala for inserts and updates into HBase.<\/b><\/li>\n<\/ul>\n<\/div>\n<\/div>\n
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      <\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

      Answer : Impala was the first to bring SQL querying to the public in April 2013…<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"passster_activate_protection":false,"passster_protect_child_pages":"","passster_protection_type":"password","passster_password":"","passster_activate_overwrite_defaults":"","passster_headline":"","passster_instruction":"","passster_placeholder":"","passster_button":"","passster_id":"","passster_activate_misc_settings":"","passster_redirect_url":"","passster_hide":"no","passster_area_shortcode":"","gtb_hide_title":false,"gtb_wrap_title":false,"gtb_class_title":"","gtb_remove_headerfooter":false,"footnotes":""},"categories":[7014],"tags":[195,219,7032,7017,360,199,7027,7028,7016,7020,7015,7029,2936,484,7018,196,7038,7026,7031,7023,7019,7022,7021,212,7025,7039,970,711,208,972,7040,2677,975,200,284,7036,7034,7035,7030,7024,7033,7037,968],"class_list":["post-1015","post","type-post","status-publish","format-standard","hentry","category-cloudera-impala","tag-accenture-interview-questions-and-answers","tag-agreeya-solutions-interview-questions-and-answers","tag-apache-impala","tag-apache-impala-vs-hive","tag-atos-interview-questions-and-answers","tag-casting-networks-india-pvt-limited-interview-questions-and-answers","tag-cloudera","tag-cloudera-hadoop","tag-cloudera-impala","tag-cloudera-impala-api","tag-cloudera-impala-documentation","tag-cloudera-vm","tag-fis-global-business-solutions-india-pvt-ltd-interview-questions-and-answers","tag-genpact-interview-questions-and-answers","tag-hadoop-cloudera-impala","tag-ibm-interview-questions-and-answers","tag-ihs-markit-interview-questions-and-answers","tag-impala","tag-impala-hadoop","tag-impala-hadoop-architecture","tag-impala-hadoop-tutorial","tag-impala-olap","tag-impala-sql","tag-indecomm-global-services-interview-questions-and-answers","tag-install-impala-on-apache-hadoop","tag-iris-software-interview-questions-and-answers","tag-mindtree-interview-questions-and-answers","tag-nagarro-software-pvt-ltd-interview-questions-and-answers","tag-prokarma-softech-pvt-ltd-interview-questions-and-answers","tag-sapient-consulting-pvt-ltd-interview-questions-and-answers","tag-standard-chartered-global-business-services-private-limited-interview-questions-and-answers","tag-synechron-technologies-pvt-ltd-interview-questions-and-answers","tag-tata-consultancy-service-interview-questions-and-answers","tag-tech-mahindra-interview-questions-and-answers","tag-valuelabs-interview-questions-and-answers","tag-what-does-cloudera-do","tag-what-is-an-impala","tag-what-is-cdh-cloudera","tag-what-is-cloudera","tag-what-is-impala","tag-what-is-impala-in-hadoop","tag-whats-an-impala","tag-wipro-infotech-interview-questions-and-answers"],"yoast_head":"\n