WitrynaThe SHOW CURRENT ROLE statement displays roles assigned to the current user. This syntax is available in Impala 2.0 and later only, when you are using the Sentry authorization framework along with the Sentry service, as described in Using Impala with the Sentry Service (Impala 1.4 or higher only).It does not apply when you use the … Witryna7 gru 2024 · 收集信息使用COMPUTE STATS命令，查看信息使用show table/column stats。 COMPUTE STATS. 和HIVE的ANALYZE TABLE类似，这个命令主要也是为了优化查询。本来IMPALA是依靠HIVE的ANALYZE TABLE的，但是这个命令不是很好用同时不稳定，所以IMPALA自己实现个命令完成相同功能。 有两类 ...
Generating Table and Column Statistics - Cloudera
Witryna7 lut 2015 · Observations Made. We observe different behavior from impala every time we run compute stats on this particular table. Some time it finishes in 8-10 minutes, while at other times it gets stuck and keeps running for 2 hrs before throwing an exception. On occasions when the compute stats works successfully in Impala, the backend impala … Witryna4 lip 2014 · 4 Answers. Use show create table. Read the hive manual for more detail. It is DESCRIBE [EXTENDED FORMATTED] also. show create table doesn't give enough information sometimes, but DESCRIBE always does; For a view, DESCRIBE EXTENDED or FORMATTED can be used to retrieve the view's definition. cubot network
impala COMPUTE STATS 指令_小小聪的博客-CSDN博客
Witryna因为Impala目前在查询规划期间不使用空计数，所以Impala 1.4.0及更高版本通过跳过这个空计数来加速COMPUTE STATS语句。 内部细节: 在后台，COMPUTE STATS语句执行两条语句:一条通过count(*)函数计算表中每个分区(或者未分区的整个表)的行数，另一条通过NDV()函数计算每列 ... Witryna30 mar 2024 · 使用compute stats进行表信息搜集，当一个内容表或分区明显变化，重新计算统计相关数据表或分区。因为行和不同值的数量差异可能导致impala选择不同的连接顺序时，表中使用的查询。避免产生很多小文件（如果有其他程序产生的小文件，可以使用中间表，将小文件数据存放到中间表。 WitrynaSHOW TABLE STATS provides some general information about the table, such as the number of files, overall size of the data, whether some or all of the data is in … eastenders 11th february 2008