http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/3be0f122/docs/topics/impala_errata.xml ---------------------------------------------------------------------- diff --git a/docs/topics/impala_errata.xml b/docs/topics/impala_errata.xml new file mode 100644 index 0000000..c7ad9c0 --- /dev/null +++ b/docs/topics/impala_errata.xml @@ -0,0 +1,1378 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> +<concept id="errata"> + <title>Impala Documentation Errata</title> + <titlealts audience="PDF"><navtitle>Doc Errata</navtitle></titlealts> + <prolog> + <metadata> + <data name="Category" value="Impala"/> + <data name="Category" value="Release Notes" /> + <data name="Category" value="New Features" /> + <data name="Category" value="What's New" /> + <data name="Category" value="Fixed Issues" /> + <data name="Category" value="Incompatible Changes" /> + </metadata> + </prolog> + + <conbody> + + <p> + This page shows changes in the Impala documentation. + These different views are experiments to see what kind(s) of + representation are most helpful. + Some changes are tied to a release. + Other improvements are the result of a particular JIRA issue and have + been backported to multiple releases where appropriate. + </p> + + <p outputclass="toc inpage"/> + </conbody> + + <concept id="by_release"> + <title>Changes by Release</title> + <conbody> + <p> + This section shows recent releases of CDH and corresponding Impala releases, + and the documentation pages that have substantial changes for each release. + </p> + <p outputclass="toc inpage"/> + </conbody> + + <concept id="release_2_6_0"> + <title>CDH 5.8 / Impala 2.6.0</title> + <conbody> + <ul> + <li><xref outputclass="release_2_6_0" href="impala_alter_table.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_breakpad.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_create_database.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_create_table.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_complex_types.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_drop_database.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_drop_table.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_perf_stats.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_insert.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_reserved_words.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_load_data.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_parquet_annotate_strings_utf8.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_parquet_fallback_schema_resolution.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_runtime_bloom_filter_size.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_runtime_filter_max_size.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_runtime_filter_min_size.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_runtime_filter_mode.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_runtime_filtering.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_s3_skip_insert_staging.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_select.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_s3.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_txtfile.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_avro.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_parquet.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_rcfile.xml"/></li> + <li><xref outputclass="release_2_6_0" href="impala_seqfile.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="release_2_5_0"> + <title>CDH 5.7 / Impala 2.5.0</title> + <conbody> + <ul> + <li><xref outputclass="release_2_5_0" href="impala_admission.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_count.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_create_database.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_create_function.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_create_table.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_describe.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_disable_row_runtime_filtering.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_disable_streaming_preaggregations.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_drop_function.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_datetime_functions.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_misc_functions.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_reserved_words.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_string_functions.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_udf.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_joins.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_load_data.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_max.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_max_num_runtime_filters.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_min.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_optimize_partition_key_scans.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_partitioning.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_runtime_bloom_filter_size.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_runtime_filter_max_size.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_runtime_filter_min_size.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_runtime_filter_mode.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_runtime_filter_wait_time_ms.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_shell_running_commands.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_runtime_filtering.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_scan_node_codegen_threshold.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_schedule_random_replica.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_set.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_show.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_operators.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_scalability.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_processes.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_truncate_table.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_perf_hdfs_caching.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_impala_shell.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_parquet.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_shell_commands.xml"/></li> + <li><xref outputclass="release_2_5_0" href="impala_shell_options.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="release_2_3_0"> + <title>CDH 5.5 / Impala 2.3.0</title> + <conbody> + <ul> + <li><xref outputclass="release_2_3_0" href="impala_alter_table.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_array.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_avg.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_compute_stats.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_count.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_create_database.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_create_function.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_create_table.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_create_view.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_complex_types.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_jdbc.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_odbc.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_ssl.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_describe.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_drop_database.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_drop_table.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_exec_single_node_rows_threshold.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_authorization.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_grant.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_group_by.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_insert.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_bit_functions.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_datetime_functions.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_math_functions.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_reserved_words.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_string_functions.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_conversion_functions.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_udf.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_joins.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_live_progress.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_live_summary.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_load_data.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_map.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_max.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_min.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_ndv.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_order_by.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_aliases.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_tables.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_views.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_partitioning.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_refresh.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_revoke.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_select.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_set.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_operators.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_struct.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_sum.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_subqueries.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_truncate_table.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_hbase.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_txtfile.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_avro.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_parquet.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_rcfile.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_seqfile.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_shell_commands.xml"/></li> + <li><xref outputclass="release_2_3_0" href="impala_shell_options.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="release_2_2_3"> + <title>CDH 5.4 / Impala 2.2.3</title> + <conbody> + <ul> + <li><xref outputclass="release_2_2_3" href="impala_datetime_functions.xml"/></li> + <li><xref outputclass="release_2_2_3" href="impala_parquet_file_size.xml"/></li> + <li><xref outputclass="release_2_2_3" href="impala_isilon.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="release_2_2_0"> + <title>CDH 5.4 / Impala 2.2.0</title> + <conbody> + <ul> + <li><xref outputclass="release_2_2_0" href="impala_alter_table.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_alter_view.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_incompatible_changes.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_intro.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_compute_stats.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_create_database.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_create_table.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_create_view.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_ddl.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_dml.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_drop_database.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_drop_table.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_explain.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_insert.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_invalidate_metadata.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_conditional_functions.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_datetime_functions.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_faq.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_install.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_math_functions.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_conversion_functions.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_load_data.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_disk_space.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_tables.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_partitioning.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_refresh.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_select.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_show.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_scalability.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_timestamp.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_truncate_table.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_performance.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_explain_plan.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_perf_hdfs_caching.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_logging.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_s3.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_txtfile.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_parquet.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_lineage.xml"/></li> + <li><xref outputclass="release_2_2_0" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="release_2_1_0"> + <title>CDH 5.3 / Impala 2.1.0</title> + <conbody> + <ul> + <li><xref outputclass="release_2_1_0" href="impala_compute_stats.xml"/></li> + <li><xref outputclass="release_2_1_0" href="impala_drop_stats.xml"/></li> + <li><xref outputclass="release_2_1_0" href="impala_exec_single_node_rows_threshold.xml"/></li> + <li><xref outputclass="release_2_1_0" href="impala_reserved_words.xml"/></li> + <li><xref outputclass="release_2_1_0" href="impala_ports.xml"/></li> + <li><xref outputclass="release_2_1_0" href="impala_txtfile.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="release_2_0_1"> + <title>CDH 5.2 / Impala 2.0.1</title> + <conbody> + <ul> + <li><xref outputclass="release_2_0_1" href="impala_perf_stats.xml"/></li> + <li><xref outputclass="release_2_0_1" href="impala_math_functions.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="release_2_0_0"> + <title>CDH 5.2 / Impala 2.0.0</title> + <conbody> + <ul> + <li><xref outputclass="release_2_0_0" href="impala_appx_count_distinct.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_avg.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_incompatible_changes.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_char.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_compression_codec.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_count.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_create_function.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_create_table.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_ddl.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_disable_unsafe_spills.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_exec_single_node_rows_threshold.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_kerberos.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_grant.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_having.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_file_formats.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_analytic_functions.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_functions.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_datetime_functions.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_faq.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_misc_functions.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_perf_cookbook.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_prereqs.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_reserved_words.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_string_functions.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_udf.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_joins.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_limit.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_literals.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_max.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_min.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_ndv.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_query_timeout_s.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_hints.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_query_options.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_revoke.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_resource_management.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_set.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_show.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_operators.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_stddev.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_string.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_sum.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_timeouts.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_subqueries.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_txtfile.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_varchar.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_variance.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_shell_commands.xml"/></li> + <li><xref outputclass="release_2_0_0" href="impala_shell_options.xml"/></li> + </ul> + +</conbody> +</concept> +</concept> + + <concept id="by_jira"> + <title>Changes by JIRA Issue</title> + <conbody> + <p> + This section lists Impala-related issues from the Impala issue-tracking system. + These items represent new features, fixes for documentation bugs, and workarounds + and notices for code bugs or limitations. + The same text may be reused in identical form on multiple pages. + Use this section to cross-check the documentation changes for feature requests and + problem reports, and to see the details in the issue-tracking system for features + and fixes that are only mentioned briefly in the documentation, such as performance + improvements that do not require any user tuning actions. + </p> + </conbody> + + <concept id="issue_IMPALA-3732"> + <title>IMPALA-3732: Avro scanner can break on strings >= 2GB</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3732";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3732" href="impala_char.xml"/></li> + <li><xref outputclass="issue_IMPALA-3732" href="impala_varchar.xml"/></li> + <li><xref outputclass="issue_IMPALA-3732" href="impala_avro.xml"/></li> + <li><xref outputclass="issue_IMPALA-3732" href="impala_string.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3679"> + <title>IMPALA-3679: Zero copy reads don't work with encryption zones</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3679";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3679" href="impala_perf_hdfs_caching.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3662"> + <title>IMPALA-3662: Parquet scanner memory increase after IMPALA-2736</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3662";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3662" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3581"> + <title>IMPALA-3581: Change Default Minidump Location to /var/log/$daemon</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3581";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3581" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3558"> + <title>IMPALA-3558: DROP TABLE PURGE on S3A table may not delete externally written files</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3558";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3558" href="impala_s3.xml"/></li> + <li><xref outputclass="issue_IMPALA-3558" href="impala_drop_table.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3554"> + <title>IMPALA-3554: Use catalog's principal to talk to sentry in kerberized Impala clusters</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3554";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3554" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-3554" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3490"> + <title>IMPALA-3490: Add Flag to Cap Maximum Minidump Size</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3490";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3490" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3480"> + <title>IMPALA-3480: Add query options to set min / max filter sizes</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3480";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3480" href="impala_runtime_filter_min_size.xml"/></li> + <li><xref outputclass="issue_IMPALA-3480" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-3480" href="impala_runtime_filter_max_size.xml"/></li> + <li><xref outputclass="issue_IMPALA-3480" href="impala_runtime_filtering.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3471"> + <title>IMPALA-3471: TopN should be able to spill</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3471";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3471" href="impala_scalability.xml"/></li> + <li><xref outputclass="issue_IMPALA-3471" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3453"> + <title>IMPALA-3453: S3 : Uneven split sizes are generated for Parquet causing execution skew</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3453";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3453" href="impala_s3.xml"/></li> + <li><xref outputclass="issue_IMPALA-3453" href="impala_avro.xml"/></li> + <li><xref outputclass="issue_IMPALA-3453" href="impala_parquet.xml"/></li> + <li><xref outputclass="issue_IMPALA-3453" href="impala_select.xml"/></li> + <li><xref outputclass="issue_IMPALA-3453" href="impala_seqfile.xml"/></li> + <li><xref outputclass="issue_IMPALA-3453" href="impala_txtfile.xml"/></li> + <li><xref outputclass="issue_IMPALA-3453" href="impala_rcfile.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3452"> + <title>IMPALA-3452: S3: Disable Impala staging for INSERTs via flag for speedup</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3452";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3452" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-3452" href="impala_s3_skip_insert_staging.xml"/></li> + <li><xref outputclass="issue_IMPALA-3452" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3439"> + <title>IMPALA-3439: Error choosing function signature in ROUND()</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3439";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3439" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-3439" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3397"> + <title>IMPALA-3397: Support SOURCE <file> in shell</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3397";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3397" href="impala_shell_running_commands.xml"/></li> + <li><xref outputclass="issue_IMPALA-3397" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-3397" href="impala_shell_commands.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3375"> + <title>IMPALA-3375: Investigate expensive calls to tc_delete_nothrow & tc_new during TopN for 2x speedup.</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3375";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3375" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3369"> + <title>IMPALA-3369: Add a variant of alter table to manually add column stats</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3369";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3369" href="impala_alter_table.xml"/></li> + <li><xref outputclass="issue_IMPALA-3369" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-3369" href="impala_perf_stats.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3333"> + <title>IMPALA-3333: Enable global runtime filtering by default</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3333";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3333" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-3333" href="impala_runtime_filtering.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3232"> + <title>IMPALA-3232: Allow table refs in subqueries to refer to WITH-clause view in parent block.</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3232";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3232" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-3232" href="impala_operators.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3199"> + <title>IMPALA-3199: Enable Admission Control by default (without limits)</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3199";>Issue</xref></p> + <ul> +<!-- <li><xref outputclass="issue_IMPALA-3199" href="admin_impala_admission_control.xml"/></li> --> + <li><xref outputclass="issue_IMPALA-3199" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-3199" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3163"> + <title>IMPALA-3163: DECIMAL casting to a TIMESTAMP doesn't keep precision</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3163";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3163" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-3163" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3155"> + <title>IMPALA-3155: CHAR expression in case statement is implicitly cast to string</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3155";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3155" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-3155" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3095"> + <title>IMPALA-3095: Allow additional Kerberos users to be authorized to access internal APIs</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3095";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3095" href="impala_kerberos.xml"/></li> + <li><xref outputclass="issue_IMPALA-3095" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3092"> + <title>IMPALA-3092: Cannot query tables after add columns for AVRO table</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3092";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3092" href="impala_alter_table.xml"/></li> + <li><xref outputclass="issue_IMPALA-3092" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3077"> + <title>IMPALA-3077: Runtime filters should be retained even when spilling</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3077";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3077" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3054"> + <title>IMPALA-3054: Runtime filters are not disabled when spilling in a rare case</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3054";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3054" href="impala_scalability.xml"/></li> + <li><xref outputclass="issue_IMPALA-3054" href="impala_partitioning.xml"/></li> + <li><xref outputclass="issue_IMPALA-3054" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-3054" href="impala_runtime_filtering.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3046"> + <title>IMPALA-3046: Allow per-row filters to evaluate non-SlotRef exprs</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3046";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3046" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3044"> + <title>IMPALA-3044: Fix admission control default value for max requests</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3044";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3044" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3039"> + <title>IMPALA-3039: Restrict the number of runtime filters generated </title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3039";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3039" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3008"> + <title>IMPALA-3008: Improve printing of filter routing table</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3008";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3008" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3007"> + <title>IMPALA-3007: Use planner cardinality estimates when sizing bloom filters</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3007";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3007" href="impala_runtime_bloom_filter_size.xml"/></li> + <li><xref outputclass="issue_IMPALA-3007" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-3007" href="impala_incompatible_changes.xml"/></li> + <li><xref outputclass="issue_IMPALA-3007" href="impala_runtime_filtering.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-3001"> + <title>IMPALA-3001: Improve usability of RUNTIME_FILTER query options</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-3001";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-3001" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2956"> + <title>IMPALA-2956: Filters should be able to target multiple scans</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2956";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2956" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2867"> + <title>IMPALA-2867: Load data inpath chokes on impala staging directories</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2867";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2867" href="impala_load_data.xml"/></li> + <li><xref outputclass="issue_IMPALA-2867" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2844"> + <title>IMPALA-2844: Select count(*) from RCFileTable throw NotImplementedException in Impala 2.3.0</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2844";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2844" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-2844" href="impala_avro.xml"/></li> + <li><xref outputclass="issue_IMPALA-2844" href="impala_complex_types.xml"/></li> + <li><xref outputclass="issue_IMPALA-2844" href="impala_seqfile.xml"/></li> + <li><xref outputclass="issue_IMPALA-2844" href="impala_txtfile.xml"/></li> + <li><xref outputclass="issue_IMPALA-2844" href="impala_rcfile.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2843"> + <title>IMPALA-2843: Impala should read java udfs created from Hive</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2843";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2843" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-2843" href="impala_create_function.xml"/></li> + <li><xref outputclass="issue_IMPALA-2843" href="impala_udf.xml"/></li> + <li><xref outputclass="issue_IMPALA-2843" href="impala_drop_function.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2835"> + <title>IMPALA-2835: Hive/Impala inconsistency with parquet.column.index.access=false</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2835";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2835" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-2835" href="impala_parquet.xml"/></li> + <li><xref outputclass="issue_IMPALA-2835" href="impala_parquet_fallback_schema_resolution.xml"/></li> + <li><xref outputclass="issue_IMPALA-2835" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2749"> + <title>IMPALA-2749: Impala returns NULL when decimal and double values are multiplied in a specific order</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2749";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2749" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-2749" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2736"> + <title>IMPALA-2736: Column-wise value materialisation in Parquet scanner</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2736";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2736" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2728"> + <title>IMPALA-2728: TestTpchMemLimitError.test_low_mem_limit_q21 exceeds mem_limit of 700M</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2728";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2728" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2696"> + <title>IMPALA-2696: Simple scheduler always uses the same replica which can create hot spots</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2696";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2696" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2688"> + <title>IMPALA-2688: Group by on Decimal data type doesn't get CodeGened </title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2688";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2688" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2686"> + <title>IMPALA-2686: Implement google BreakPad based crash handler for impala.</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2686";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2686" href="impala_breakpad.xml"/></li> + <li><xref outputclass="issue_IMPALA-2686" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2681"> + <title>IMPALA-2681: Improve Decimal arithmetic performance by using a cheaper overflow check </title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2681";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2681" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2660"> + <title>IMPALA-2660: Respect auth_to_local rules from hdfs configs (core-site.xml)</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2660";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2660" href="impala_kerberos.xml"/></li> + <li><xref outputclass="issue_IMPALA-2660" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-2660" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2641"> + <title>IMPALA-2641: Add IF EXISTS clause to TRUNCATE TABLE statement</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2641";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2641" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-2641" href="impala_truncate_table.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2599"> + <title>IMPALA-2599: Pseudo-random sleep before acquiring kerberos ticket possibly not really pseudo-random.</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2599";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2599" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2560"> + <title>IMPALA-2560: Large memory consumption on coordinator node when handling a large number of partitions due to redundancy in TDescriptorTable</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2560";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2560" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2552"> + <title>IMPALA-2552: Runtime filter forwarding between operators</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2552";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2552" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2538"> + <title>IMPALA-2538: Per-pool default query memory limits</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2538";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2538" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-2538" href="impala_admission.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2499"> + <title>IMPALA-2499: Min/max values on partition columns</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2499";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2499" href="impala_partitioning.xml"/></li> + <li><xref outputclass="issue_IMPALA-2499" href="impala_optimize_partition_key_scans.xml"/></li> + <li><xref outputclass="issue_IMPALA-2499" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2419"> + <title>IMPALA-2419: Extend Probe filter implementation</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2419";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2419" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2382"> + <title>IMPALA-2382: Impala unable to read Java based UDFs that return a standard datatype like Float or String(This works in hive)</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2382";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2382" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2336"> + <title>IMPALA-2336: Failure to execute SQL scripts with trailing comments (including comment-only scripts)</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2336";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2336" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2257"> + <title>IMPALA-2257: Text delimiter breaks data loading build</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2257";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2257" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2251"> + <title>IMPALA-2251: Impala allows creation of text tables with same row and field delimiter</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2251";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2251" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2233"> + <title>IMPALA-2233: Impala should not choose a function signature that results in loss of precision</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2233";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2233" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2204"> + <title>IMPALA-2204: Underscore in where does not work for multi-line text </title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2204";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2204" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2196"> + <title>IMPALA-2196: Add support for DESCRIBE DATABASE similar to Hive</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2196";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2196" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-2196" href="impala_describe.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2180"> + <title>IMPALA-2180: IMPALA-2180: Extend SET command to allow setting variables in Impala Shell.</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2180";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2180" href="impala_set.xml"/></li> + <li><xref outputclass="issue_IMPALA-2180" href="impala_shell_running_commands.xml"/></li> + <li><xref outputclass="issue_IMPALA-2180" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-2180" href="impala_shell_commands.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2179"> + <title>IMPALA-2179: IMPALA-2179: Extend Impala shell to allow passing variables through the command line</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2179";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2179" href="impala_shell_running_commands.xml"/></li> + <li><xref outputclass="issue_IMPALA-2179" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-2179" href="impala_impala_shell.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2147"> + <title>IMPALA-2147: Support for null-safe equal/IS [NOT] DISTINCT FROM</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2147";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2147" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2130"> + <title>IMPALA-2130: hdfs-parquet-scanner's verification of file version is not correct</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2130";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2130" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2111"> + <title>IMPALA-2111: Parquet TIMESTAMP is in milliseconds</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2111";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2111" href="impala_timestamp.xml"/></li> + <li><xref outputclass="issue_IMPALA-2111" href="impala_parquet.xml"/></li> + <li><xref outputclass="issue_IMPALA-2111" href="impala_bigint.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2070"> + <title>IMPALA-2070: Include the database comment when showing databases</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2070";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2070" href="impala_show.xml"/></li> + <li><xref outputclass="issue_IMPALA-2070" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-2070" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-2069"> + <title>IMPALA-2069: Cannot write string column to parquet with UTF-8 annotation</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-2069";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-2069" href="impala_parquet_annotate_strings_utf8.xml"/></li> + <li><xref outputclass="issue_IMPALA-2069" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-2069" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1934"> + <title>IMPALA-1934: impala-shell to support reading password from command line when LDAP authentication is used</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1934";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1934" href="impala_shell_options.xml"/></li> + <li><xref outputclass="issue_IMPALA-1934" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1881"> + <title>IMPALA-1881: Maximize data locality when scanning Parquet files with multiple row groups.</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1881";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1881" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1878"> + <title>IMPALA-1878: Support INSERT and LOAD DATA to S3</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1878";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1878" href="impala_s3.xml"/></li> + <li><xref outputclass="issue_IMPALA-1878" href="impala_alter_table.xml"/></li> + <li><xref outputclass="issue_IMPALA-1878" href="impala_create_table.xml"/></li> + <li><xref outputclass="issue_IMPALA-1878" href="impala_load_data.xml"/></li> + <li><xref outputclass="issue_IMPALA-1878" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-1878" href="impala_drop_database.xml"/></li> + <li><xref outputclass="issue_IMPALA-1878" href="impala_insert.xml"/></li> + <li><xref outputclass="issue_IMPALA-1878" href="impala_create_database.xml"/></li> + <li><xref outputclass="issue_IMPALA-1878" href="impala_drop_table.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1787"> + <title>IMPALA-1787: Case-insensitivity modifier for regular expressions</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1787";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1787" href="impala_string_functions.xml"/></li> + <li><xref outputclass="issue_IMPALA-1787" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1772"> + <title>IMPALA-1772: Additional date / time fns</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1772";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1772" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1771"> + <title>IMPALA-1771: Hyperbolic trig fns etc.</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1771";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1771" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-1771" href="impala_math_functions.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1755"> + <title>IMPALA-1755: Disabling codegen on parquet scanner causes some queries' performance to regress</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1755";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1755" href="impala_scan_node_codegen_threshold.xml"/></li> + <li><xref outputclass="issue_IMPALA-1755" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1748"> + <title>IMPALA-1748: Provide support for registering permanent udfs</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1748";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1748" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-1748" href="impala_create_function.xml"/></li> + <li><xref outputclass="issue_IMPALA-1748" href="impala_udf.xml"/></li> + <li><xref outputclass="issue_IMPALA-1748" href="impala_incompatible_changes.xml"/></li> + <li><xref outputclass="issue_IMPALA-1748" href="impala_processes.xml"/></li> + <li><xref outputclass="issue_IMPALA-1748" href="impala_drop_function.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1740"> + <title>IMPALA-1740: Impala cannot deal with skip.header.line.count</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1740";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1740" href="impala_new_features.xml"/></li> + <li><xref outputclass="issue_IMPALA-1740" href="impala_txtfile.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1675"> + <title>IMPALA-1675: Timestamp: Adding/subtracting very large time intervals to timestamps produces incorrect result</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1675";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1675" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1651"> + <title>IMPALA-1651: CREATE TABLE LIKE should not copy caching directives of the source table.</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1651";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1651" href="impala_incompatible_changes.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1599"> + <title>IMPALA-1599: Improve query start-up time with many fragment instances</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1599";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1599" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1588"> + <title>IMPALA-1588: Cache HDFS file handle to avoid repeated hdfs fopen call</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1588";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1588" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1568"> + <title>IMPALA-1568: Find / repair missing partitions command</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1568";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1568" href="impala_alter_table.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1480"> + <title>IMPALA-1480: Slow DDL statements for tables with large number of partitions</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1480";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1480" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1477"> + <title>IMPALA-1477: Add UUID function</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1477";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1477" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1305"> + <title>IMPALA-1305: Improve performance of high cardinality / low reduction aggs</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1305";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1305" href="impala_disable_streaming_preaggregations.xml"/></li> + <li><xref outputclass="issue_IMPALA-1305" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1168"> + <title>IMPALA-1168: Finer grain Admission Control timeout control</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1168";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1168" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1139"> + <title>IMPALA-1139: Implement TRUNCATE TABLE statement</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1139";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1139" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1079"> + <title>IMPALA-1079: Impalad crashes while trying to run tpcds-q34</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1079";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1079" href="impala_shell_options.xml"/></li> + </ul> + +</conbody> +</concept> + + <concept id="issue_IMPALA-1067"> + <title>IMPALA-1067: Passing Arguments through Impala Shell</title> + <conbody> + <p><xref scope="external" format="html" href="https://issues.cloudera.org/browse/IMPALA-1067";>Issue</xref></p> + <ul> + <li><xref outputclass="issue_IMPALA-1067" href="impala_new_features.xml"/></li> + </ul> + +</conbody> +</concept> + + </concept> +</concept>
http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/3be0f122/docs/topics/impala_exec_single_node_rows_threshold.xml ---------------------------------------------------------------------- diff --git a/docs/topics/impala_exec_single_node_rows_threshold.xml b/docs/topics/impala_exec_single_node_rows_threshold.xml new file mode 100644 index 0000000..a7cf102 --- /dev/null +++ b/docs/topics/impala_exec_single_node_rows_threshold.xml @@ -0,0 +1,96 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> +<concept rev="2.0.0" id="exec_single_node_rows_threshold"> + + <title>EXEC_SINGLE_NODE_ROWS_THRESHOLD Query Option (<keyword keyref="impala21"/> or higher only)</title> + <titlealts audience="PDF"><navtitle>EXEC_SINGLE_NODE_ROWS_THRESHOLD</navtitle></titlealts> + <prolog> + <metadata> + <data name="Category" value="Impala"/> + <data name="Category" value="Impala Query Options"/> + <data name="Category" value="Scalability"/> + <data name="Category" value="Performance"/> + <data name="Category" value="Developers"/> + <data name="Category" value="Data Analysts"/> + </metadata> + </prolog> + + <conbody> + + <p rev="2.0.0"> + <indexterm audience="Cloudera">EXEC_SINGLE_NODE_ROWS_THRESHOLD query option</indexterm> + This setting controls the cutoff point (in terms of number of rows scanned) below which Impala treats a query + as a <q>small</q> query, turning off optimizations such as parallel execution and native code generation. The + overhead for these optimizations is applicable for queries involving substantial amounts of data, but it + makes sense to skip them for queries involving tiny amounts of data. Reducing the overhead for small queries + allows Impala to complete them more quickly, keeping YARN resources, admission control slots, and so on + available for data-intensive queries. + </p> + + <p conref="../shared/impala_common.xml#common/syntax_blurb"/> + +<codeblock>SET EXEC_SINGLE_NODE_ROWS_THRESHOLD=<varname>number_of_rows</varname></codeblock> + + <p> + <b>Type:</b> numeric + </p> + + <p> + <b>Default:</b> 100 + </p> + + <p> + <b>Usage notes:</b> Typically, you increase the default value to make this optimization apply to more queries. + If incorrect or corrupted table and column statistics cause Impala to apply this optimization + incorrectly to queries that actually involve substantial work, you might see the queries being slower as a + result of remote reads. In that case, recompute statistics with the <codeph>COMPUTE STATS</codeph> + or <codeph>COMPUTE INCREMENTAL STATS</codeph> statement. If there is a problem collecting accurate + statistics, you can turn this feature off by setting the value to -1. + </p> + + <p conref="../shared/impala_common.xml#common/internals_blurb"/> + + <p> + This setting applies to query fragments where the amount of data to scan can be accurately determined, either + through table and column statistics, or by the presence of a <codeph>LIMIT</codeph> clause. If Impala cannot + accurately estimate the size of the input data, this setting does not apply. + </p> + + <p rev="2.3.0"> + In <keyword keyref="impala23_full"/> and higher, where Impala supports the complex data types <codeph>STRUCT</codeph>, + <codeph>ARRAY</codeph>, and <codeph>MAP</codeph>, if a query refers to any column of those types, + the small-query optimization is turned off for that query regardless of the + <codeph>EXEC_SINGLE_NODE_ROWS_THRESHOLD</codeph> setting. + </p> + + <p> + For a query that is determined to be <q>small</q>, all work is performed on the coordinator node. This might + result in some I/O being performed by remote reads. The savings from not distributing the query work and not + generating native code are expected to outweigh any overhead from the remote reads. + </p> + + <p conref="../shared/impala_common.xml#common/added_in_210"/> + + <p conref="../shared/impala_common.xml#common/example_blurb"/> + + <p> + A common use case is to query just a few rows from a table to inspect typical data values. In this example, + Impala does not parallelize the query or perform native code generation because the result set is guaranteed + to be smaller than the threshold value from this query option: + </p> + +<codeblock>SET EXEC_SINGLE_NODE_ROWS_THRESHOLD=500; +SELECT * FROM enormous_table LIMIT 300; +</codeblock> + +<!-- Don't have any other places that tie into this particular optimization technique yet. +Potentially: conceptual topics about code generation, distributed queries + +<p conref="../shared/impala_common.xml#common/related_info"/> +<p> +</p> +--> + + </conbody> + +</concept> http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/3be0f122/docs/topics/impala_explain.xml ---------------------------------------------------------------------- diff --git a/docs/topics/impala_explain.xml b/docs/topics/impala_explain.xml new file mode 100644 index 0000000..81cc17b --- /dev/null +++ b/docs/topics/impala_explain.xml @@ -0,0 +1,228 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> +<concept id="explain"> + + <title>EXPLAIN Statement</title> + <titlealts audience="PDF"><navtitle>EXPLAIN</navtitle></titlealts> + <prolog> + <metadata> + <data name="Category" value="Impala"/> + <data name="Category" value="SQL"/> + <data name="Category" value="Querying"/> + <data name="Category" value="Reports"/> + <data name="Category" value="Planning"/> + <data name="Category" value="Performance"/> + <data name="Category" value="Troubleshooting"/> + <data name="Category" value="Administrators"/> + <data name="Category" value="Developers"/> + <data name="Category" value="Data Analysts"/> + </metadata> + </prolog> + + <conbody> + + <p> + <indexterm audience="Cloudera">EXPLAIN statement</indexterm> + Returns the execution plan for a statement, showing the low-level mechanisms that Impala will use to read the + data, divide the work among nodes in the cluster, and transmit intermediate and final results across the + network. Use <codeph>explain</codeph> followed by a complete <codeph>SELECT</codeph> query. For example: + </p> + + <p conref="../shared/impala_common.xml#common/syntax_blurb"/> + +<codeblock>EXPLAIN { <varname>select_query</varname> | <varname>ctas_stmt</varname> | <varname>insert_stmt</varname> } +</codeblock> + + <p> + The <varname>select_query</varname> is a <codeph>SELECT</codeph> statement, optionally prefixed by a + <codeph>WITH</codeph> clause. See <xref href="impala_select.xml#select"/> for details. + </p> + + <p> + The <varname>insert_stmt</varname> is an <codeph>INSERT</codeph> statement that inserts into or overwrites an + existing table. It can use either the <codeph>INSERT ... SELECT</codeph> or <codeph>INSERT ... + VALUES</codeph> syntax. See <xref href="impala_insert.xml#insert"/> for details. + </p> + + <p> + The <varname>ctas_stmt</varname> is a <codeph>CREATE TABLE</codeph> statement using the <codeph>AS + SELECT</codeph> clause, typically abbreviated as a <q>CTAS</q> operation. See + <xref href="impala_create_table.xml#create_table"/> for details. + </p> + + <p conref="../shared/impala_common.xml#common/usage_notes_blurb"/> + + <p> + You can interpret the output to judge whether the query is performing efficiently, and adjust the query + and/or the schema if not. For example, you might change the tests in the <codeph>WHERE</codeph> clause, add + hints to make join operations more efficient, introduce subqueries, change the order of tables in a join, add + or change partitioning for a table, collect column statistics and/or table statistics in Hive, or any other + performance tuning steps. + </p> + + <p> + The <codeph>EXPLAIN</codeph> output reminds you if table or column statistics are missing from any table + involved in the query. These statistics are important for optimizing queries involving large tables or + multi-table joins. See <xref href="impala_compute_stats.xml#compute_stats"/> for how to gather statistics, + and <xref href="impala_perf_stats.xml#perf_stats"/> for how to use this information for query tuning. + </p> + + <p conref="../shared/impala_common.xml#common/explain_interpret"/> + + <p> + If you come from a traditional database background and are not familiar with data warehousing, keep in mind + that Impala is optimized for full table scans across very large tables. The structure and distribution of + this data is typically not suitable for the kind of indexing and single-row lookups that are common in OLTP + environments. Seeing a query scan entirely through a large table is common, not necessarily an indication of + an inefficient query. Of course, if you can reduce the volume of scanned data by orders of magnitude, for + example by using a query that affects only certain partitions within a partitioned table, then you might be + able to optimize a query so that it executes in seconds rather than minutes. + </p> + + <p> + For more information and examples to help you interpret <codeph>EXPLAIN</codeph> output, see + <xref href="impala_explain_plan.xml#perf_explain"/>. + </p> + + <p rev="1.2"> + <b>Extended EXPLAIN output:</b> + </p> + + <p rev="1.2"> + For performance tuning of complex queries, and capacity planning (such as using the admission control and + resource management features), you can enable more detailed and informative output for the + <codeph>EXPLAIN</codeph> statement. In the <cmdname>impala-shell</cmdname> interpreter, issue the command + <codeph>SET EXPLAIN_LEVEL=<varname>level</varname></codeph>, where <varname>level</varname> is an integer + from 0 to 3 or corresponding mnemonic values <codeph>minimal</codeph>, <codeph>standard</codeph>, + <codeph>extended</codeph>, or <codeph>verbose</codeph>. + </p> + + <p rev="1.2"> + When extended <codeph>EXPLAIN</codeph> output is enabled, <codeph>EXPLAIN</codeph> statements print + information about estimated memory requirements, minimum number of virtual cores, and so on. + <!-- + that you can use to fine-tune the resource management options explained in <xref href="impala_resource_management.xml#rm_options"/>. + (The estimated memory requirements are intentionally on the high side, to allow a margin for error, + to avoid cancelling a query unnecessarily if you set the <codeph>MEM_LIMIT</codeph> option to the estimated memory figure.) + --> + </p> + + <p> + See <xref href="impala_explain_level.xml#explain_level"/> for details and examples. + </p> + + <p conref="../shared/impala_common.xml#common/example_blurb"/> + + <p> + This example shows how the standard <codeph>EXPLAIN</codeph> output moves from the lowest (physical) level to + the higher (logical) levels. The query begins by scanning a certain amount of data; each node performs an + aggregation operation (evaluating <codeph>COUNT(*)</codeph>) on some subset of data that is local to that + node; the intermediate results are transmitted back to the coordinator node (labelled here as the + <codeph>EXCHANGE</codeph> node); lastly, the intermediate results are summed to display the final result. + </p> + +<codeblock id="explain_plan_simple">[impalad-host:21000] > explain select count(*) from customer_address; ++----------------------------------------------------------+ +| Explain String | ++----------------------------------------------------------+ +| Estimated Per-Host Requirements: Memory=42.00MB VCores=1 | +| | +| 03:AGGREGATE [MERGE FINALIZE] | +| | output: sum(count(*)) | +| | | +| 02:EXCHANGE [PARTITION=UNPARTITIONED] | +| | | +| 01:AGGREGATE | +| | output: count(*) | +| | | +| 00:SCAN HDFS [default.customer_address] | +| partitions=1/1 size=5.25MB | ++----------------------------------------------------------+ +</codeblock> + + <p> + These examples show how the extended <codeph>EXPLAIN</codeph> output becomes more accurate and informative as + statistics are gathered by the <codeph>COMPUTE STATS</codeph> statement. Initially, much of the information + about data size and distribution is marked <q>unavailable</q>. Impala can determine the raw data size, but + not the number of rows or number of distinct values for each column without additional analysis. The + <codeph>COMPUTE STATS</codeph> statement performs this analysis, so a subsequent <codeph>EXPLAIN</codeph> + statement has additional information to use in deciding how to optimize the distributed query. + </p> + + <!-- To do: + Re-run these examples with more substantial tables populated with data. + --> + +<codeblock rev="1.2">[localhost:21000] > set explain_level=extended; +EXPLAIN_LEVEL set to extended +[localhost:21000] > explain select x from t1; +[localhost:21000] > explain select x from t1; ++----------------------------------------------------------+ +| Explain String | ++----------------------------------------------------------+ +| Estimated Per-Host Requirements: Memory=32.00MB VCores=1 | +| | +| 01:EXCHANGE [PARTITION=UNPARTITIONED] | +| | hosts=1 per-host-mem=unavailable | +<b>| | tuple-ids=0 row-size=4B cardinality=unavailable |</b> +| | | +| 00:SCAN HDFS [default.t2, PARTITION=RANDOM] | +| partitions=1/1 size=36B | +<b>| table stats: unavailable |</b> +<b>| column stats: unavailable |</b> +| hosts=1 per-host-mem=32.00MB | +<b>| tuple-ids=0 row-size=4B cardinality=unavailable |</b> ++----------------------------------------------------------+ +</codeblock> + +<codeblock rev="1.2">[localhost:21000] > compute stats t1; ++-----------------------------------------+ +| summary | ++-----------------------------------------+ +| Updated 1 partition(s) and 1 column(s). | ++-----------------------------------------+ +[localhost:21000] > explain select x from t1; ++----------------------------------------------------------+ +| Explain String | ++----------------------------------------------------------+ +| Estimated Per-Host Requirements: Memory=64.00MB VCores=1 | +| | +| 01:EXCHANGE [PARTITION=UNPARTITIONED] | +| | hosts=1 per-host-mem=unavailable | +| | tuple-ids=0 row-size=4B cardinality=0 | +| | | +| 00:SCAN HDFS [default.t1, PARTITION=RANDOM] | +| partitions=1/1 size=36B | +<b>| table stats: 0 rows total |</b> +<b>| column stats: all |</b> +| hosts=1 per-host-mem=64.00MB | +<b>| tuple-ids=0 row-size=4B cardinality=0 |</b> ++----------------------------------------------------------+ +</codeblock> + + <p conref="../shared/impala_common.xml#common/security_blurb"/> + <p conref="../shared/impala_common.xml#common/redaction_yes"/> + + <p conref="../shared/impala_common.xml#common/cancel_blurb_no"/> + + <p conref="../shared/impala_common.xml#common/permissions_blurb"/> + <p rev="CDH-19187"> + <!-- Doublecheck these details. Does EXPLAIN really need any permissions? --> + The user ID that the <cmdname>impalad</cmdname> daemon runs under, + typically the <codeph>impala</codeph> user, must have read + and execute permissions for all applicable directories in all source tables + for the query that is being explained. + (A <codeph>SELECT</codeph> operation could read files from multiple different HDFS directories + if the source table is partitioned.) + </p> + + <p conref="../shared/impala_common.xml#common/related_info"/> + <p> + <xref href="impala_select.xml#select"/>, + <xref href="impala_insert.xml#insert"/>, + <xref href="impala_create_table.xml#create_table"/>, + <xref href="impala_explain_plan.xml#explain_plan"/> + </p> + + </conbody> +</concept>
