Actually, what we needed to use inside of the Hive date functions to use our timestamp columns was this:
from_unixtime(bigint unixtime[, string format]) The rest of the points I brought up remain the same, IIRC... -- Felix On Mon, Apr 8, 2013 at 5:44 PM, Felix GV <[email protected]> wrote: > You can use --map-column-hive to manually specify which columns should be > mapped to a timestamp instead of a string. See the sqoop > guide<http://sqoop.apache.org/docs/1.4.1-incubating/SqoopUserGuide.html#_importing_data_into_hive>for > more info. > > A couple caveats: > > - I don't know of any way of changing the default sqoop behavior so > you don't need to manually name all relevant columns in every table you're > sqooping. > - MySQL's date columns break when converted with this mapping > (datetime and timestamp work, but not date). In order to map a MySQL date > column, I had to use a custom query that converted the column to a datetime > (with 00:00:00 time values) inside of MySQL so that sqoop doesn't choke on > it. Obviously, this is even more annoying than having to set > --map-column-hive, since it makes each sqoop command even more ad-hoc. > - In the end, although all of that worked (in a very ad-hoc manner), > we decided to drop it all and just go with string columns in Hive, since > all (or most) of the Hive date-related > functions<https://cwiki.apache.org/Hive/languagemanual-udf.html#LanguageManualUDF-DateFunctions>take > only strings as input parameters, and not timestamps, so having > timestamp columns meant we had to use to_date(string timestamp) inside of > each Hive date function, which made all of our queries a bit unwieldy, and > also (I assume) precluded us from gaining any speed advantages from having > timestamps instead of strings. > > The last point makes me think Hive timestamps are not really ready > for prime time yet... They seem to be tacked on top of the system in a way > that's fully well integrated. > > Please let me know if you think I'm drawing the wrong conclusions from > this :) ...! > > -- > Felix > > > On Sun, Apr 7, 2013 at 6:23 AM, Santosh Achhra <[email protected]>wrote: > >> Hello, >> >> I am using hive version 0.9 which supports timestamp fields. When I >> import data using sqoop using hive-import option, sqoop converts timestamp >> fields to string. >> >> sqoop version is Sqoop 1.4.1-cdh4.1.0 >> >> >> Good wishes,always ! >> Santosh >> > >
