在Impala/Hive中删除多个分区 [英] Dropping multiple partitions in Impala/Hive

问题描述

1-我正在尝试一次删除多个分区，但是很难用Impala或Hive做到这一点.我尝试了以下查询，使用和不使用':

1- I'm trying to delete multiple partitions at once, but struggling to do it with either Impala or Hive. I tried the following query, with and without ':

ALTER TABLE cz_prd_corrti_st.s1mme_transstats_info DROP IF EXISTS PARTITION (pr_load_time='20170701000317') PARTITION (pr_load_time='20170701000831')

ALTER TABLE cz_prd_corrti_st.s1mme_transstats_info DROP IF EXISTS PARTITION (pr_load_time='20170701000317') PARTITION (pr_load_time='20170701000831')

我得到的错误如下:

AnalysisException: 第3行的语法错误:PARTITION(pr_load_time ='20170701000831')^ 遇到:预期分区:缓存，位置，清除，设置， 导致未命中的原因:异常:语法错误

AnalysisException: Syntax error in line 3: PARTITION (pr_load_time='20170701000831') ^ Encountered: PARTITION Expected: CACHED, LOCATION, PURGE, SET, UNCACHED CAUSED BY: Exception: Syntax error

分区列为bigint类型，查询仅删除一个分区即可正常工作:

The partition column is bigint type, query for deleting only one partition works as expected:

ALTER TABLE cz_prd_corrti_st.s1mme_transstats_info DROP IF EXISTS
PARTITION   (pr_load_time='20170701000317')

2-是先删除hdfs数据，然后将分区放在Impala/Hive中的好习惯吗?或者反之亦然?

2- Is it a good practice delete the hdfs data first and then drop the partitions in Impala/Hive, or is it supposed to be done vice versa?

推荐答案

1.

您的语法错误.
在DROP命令中，分区应以逗号分隔.

1.

Your syntax is wrong.
In the DROP command the partitions should be separated by commas.

演示

hive> create table t (i int) partitioned by (p int);
OK

hive> alter table t add partition (p=1) partition(p=2) partition(p=3) partition(p=4) partition(p=5);
OK

hive> show partitions t;
OK
partition
p=1
p=2
p=3
p=4
p=5

hive> alter table t drop if exists partition (p=1),partition (p=2),partition(p=3);
Dropped the partition p=1
Dropped the partition p=2
Dropped the partition p=3
OK

hive> show partitions t;
OK
partition
p=4
p=5

2.

您可以放下一个范围.

2.

You can drop a range.

演示

hive> create table t (i int) partitioned by (p int);
OK

hive> alter table t add partition (p=1) partition(p=2) partition(p=3) partition(p=4) partition(p=5);
OK

hive> show partitions t;
OK
partition
p=1
p=2
p=3
p=4
p=5

hive> alter table t drop if exists partition (p<=3);
Dropped the partition p=1
Dropped the partition p=2
Dropped the partition p=3
OK

hive> show partitions t;
OK
partition
p=4
p=5

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