跳至主要内容

Mysterious sqoop1 export options

Ever want to export periodically generated hive data to RDBMS?

There may be several solutions available, depends on the data size and update interval. But if you decide to use sqoop1 to export the ******Hive table******, don’t follow those handcraft solution suggestions, try the sqoop1 internal one.

The handcraft solution: copy, export, delete

As title, this kind of solution mainly consist of 3 steps.

  1. Copy data out from warehouse to general HDFS path
  2. Run sqoop command against the copied HDFS path
  3. Delete the copied HDFS path

The sqoop1 internal solution: HCatalog arguments

Run sqoop-export –help and pay attention to the ******HCatalog arguments****** section

HCatalog arguments:
--hcatalog-database <arg>                        HCatalog database name
--hcatalog-home <hdir>                           Override $HCAT_HOME
--hcatalog-partition-keys <partition-key>        Sets the partition
                         keys to use when
                         importing to hive
--hcatalog-partition-values <partition-value>    Sets the partition
                         values to use when
                         importing to hive
--hcatalog-table <arg>                           HCatalog table name
--hive-home <dir>                                Override $HIVE_HOME
--hive-partition-key <partition-key>             Sets the partition key
                         to use when importing
                         to hive
--hive-partition-value <partition-value>         Sets the partition
                         value to use when
                         importing to hive
--map-column-hive <arg>                          Override mapping for
                         specific column to
                         hive types.

Note that –hcatalog-partition-keys and –hcatalog-partition-values and –hive-partition-key and –hive-partition-value.

Try to specify partitions and partition values as comma separated list for pural ones.

Even these arguments’ help string is wrongly stated they are ******import****** options, they did the partition filtering job very good when exporting.

评论

此博客中的热门博文

Use MobaDiff with git difftool

Recently there's an activity in IT that forces the deletion of all unauthorized softwares from all work machines. Unfortunately, kdiff3 is one in the list. As it is generally okay to use vimdiff as an alternative for kdiff3, A gui tool is better suited for desktop workflows. Known that MobaXterm is shipping a gui diff tool named MobaDiff. But it only appears in the windows right click context menu. Find the real application name takes me some time to search in the windows registry. "MobaRTE.exe", which is the one invoked by HKCR\*\shell\MobaDiff. And it was invoked with "-contextdiff" switch to show MobaDiff UI, while when the switch is "-contextedit" it shows MobaTextEditor. Too bad that the "-contextdiff" switch do not support pre-image post-image as other diff tool did, which effectively made it unable to be used as a command line diff utility. Also MobaTech did not mention anything in their document of this Mob...

Emacs 26.2 windows Hunspell setup

 Hunspell failed with default setup With my shining new emacs26.2 setup, I am happy until trying to `M-$’ on a word. I got following error message, it used to be work by just set ispell program to hunspell. Starting new Ispell process hunspell with default dictionary... split-string: Wrong type argument: stringp, nil After some check in my customization setting. nothing found. install a copy of hunspell dictionary At first I think it was caused by no hunspell dictionary. I downloaded en US and en CA hunspell dictionary from wordlist.sf.net project. After put the .aff and .dic files into C:directory I’ve also made a symbolic link from en US ones by running the `mklink’ tool: mklink default.aff en_US.aff mklink default.dic en_US.dic Err… hunspell does not work, still. Time to read code Dig into ispell.el I suprisingly find there’re lots of hunspell specific logic. Originally I was thinking hunspell support involves no elisp work. Acturally ispell did many work to de...

XEmacs 21.5 beta 35 "kohlrabi" has been released.

If you are an old XEmacs user, you may feel happy to see this from https://www.xemacs.org/.    After ten years, XEmacs released a new version 21.5. So there's still many people cares about XEmacs. The XEmacs' source repo have been moved from altassian Bitbucket to https://heptapod.net/. As Bitbucket have been dropped Mercurial support many years ago.