There are also problems with aggregate functions. Some of them, for example, return the result with double type instead of decimal.
Queries on decimal columns may fail with exceptions, return the wrong result or run slower than similar queries with other types. For more details please see document [1]. There were analyzed major problems, connected with the decimal data type and ways to improve current approach and fix mentioned bugs. [1] https://docs.google.com/document/d/1kfWUZ_OsEmLOJu_tKZO0-ZUJwc52drrm15fyif7BmzQ/edit?usp=sharing 2018-02-06 16:28 GMT+02:00 <john.humphr...@nomura.com>: > Oh cool, thank you so much for the information. > > Any chance you can elaborate on the nature of the problems? Assuming you > stayed away from decimal UDFs, would doing regular selects and aggregates > (like max) on decimal columns cause failures? > > Also, are we talking about drill-bits actually crashing, or decimal > related queries just throwing normal exceptions/errors? > > -----Original Message----- > From: Vova Vysotskyi [mailto:vvo...@gmail.com] > Sent: Tuesday, February 06, 2018 5:24 AM > To: user@drill.apache.org > Subject: Re: Decimal Support Target Date & Workarounds? > > Hi John, > > Enabling decimal support does not make drill unstable if decimal types do > not process. > Problems may appear only when you trying to use decimal columns or some > problematic decimal UDFs. > Currently, we are actively working on completing decimal support and I > suppose it will be available in 1.13 release. > > > 2018-02-05 23:17 GMT+02:00 <john.humphr...@nomura.com>: > > > Hey, > > > > I’m on the MapR platform using Drill 1.10 at the minute. > > > > I have numerous parquet files that I need to query, but they have > > decimal data types in them. > > > > I do not actually need to query the decimal columns in general, but > > drill prevents me from querying the files as a whole even when I avoid > > those columns. > > > > I know I can “enable” decimal support. So I guess my questions are: > > > > > > 1. Will enabling decimal support actually make drill unstable, or > > does it just slow some queries down? > > > > 2. Is there any risk in enabling the support as long as I avoid > > querying the decimal columns? > > > > 3. Is decimal support being actively worked on and will it be > > available soon-ish? > > > > Thanks, > > > > -John > > > > > > PLEASE READ: This message is for the named person's use only. It may > > contain confidential, proprietary or legally privileged information. > > No confidentiality or privilege is waived or lost by any > > mistransmission. If you receive this message in error, please delete > > it and all copies from your system, destroy any hard copies and notify > > the sender. You must not, directly or indirectly, use, disclose, > > distribute, print, or copy any part of this message if you are not the > > intended recipient. Nomura Holding America Inc., Nomura Securities > > International, Inc, and their respective subsidiaries each reserve the > > right to monitor all e-mail communications through its networks. Any > > views expressed in this message are those of the individual sender, > > except where the message states otherwise and the sender is authorized > > to state the views of such entity. Unless otherwise stated, any > > pricing information in this message is indicative only, is subject to > > change and does not constitute an offer to deal at any price quoted. > > Any reference to the terms of executed transactions should be treated as > preliminary only and subject to our formal written confirmation. > > > > > > -- > Kind regards, > Volodymyr Vysotskyi > > PLEASE READ: This message is for the named person's use only. It may > contain confidential, proprietary or legally privileged information. No > confidentiality or privilege is waived or lost by any mistransmission. If > you receive this message in error, please delete it and all copies from > your system, destroy any hard copies and notify the sender. You must not, > directly or indirectly, use, disclose, distribute, print, or copy any part > of this message if you are not the intended recipient. Nomura Holding > America Inc., Nomura Securities International, Inc, and their respective > subsidiaries each reserve the right to monitor all e-mail communications > through its networks. Any views expressed in this message are those of the > individual sender, except where the message states otherwise and the sender > is authorized to state the views of such entity. Unless otherwise stated, > any pricing information in this message is indicative only, is subject to > change and does not constitute an offer to deal at any price quoted. Any > reference to the terms of executed transactions should be treated as > preliminary only and subject to our formal written confirmation. > -- Kind regards, Volodymyr Vysotskyi
