Re: Reading csv-files in parallel

2018-05-09 Thread Fabian Hueske
; Best, Esa > > > > *From:* Fabian Hueske > *Sent:* Tuesday, May 8, 2018 10:26 PM > > *To:* Esa Heikkinen > *Cc:* user@flink.apache.org > *Subject:* Re: Reading csv-files in parallel > > > > Hi, > > the Table API / SQL and the DataSet API can be used

RE: Reading csv-files in parallel

2018-05-09 Thread Esa Heikkinen
Hi Sorry the stupid question, but how to connect readTextFile (or readCsvFile), MapFunction and SQL together in Scala code ? Best, Esa From: Fabian Hueske Sent: Tuesday, May 8, 2018 10:26 PM To: Esa Heikkinen Cc: user@flink.apache.org Subject: Re: Reading csv-files in parallel Hi, the Table

Re: Reading csv-files in parallel

2018-05-08 Thread Fabian Hueske
> > *From:* Fabian Hueske > *Sent:* Tuesday, May 8, 2018 2:00 PM > > *To:* Esa Heikkinen > *Cc:* user@flink.apache.org > *Subject:* Re: Reading csv-files in parallel > > > > Hi, > > the easiest approach is to read the CSV files linewise as regular text &g

RE: Reading csv-files in parallel

2018-05-08 Thread Esa Heikkinen
(state-machine-based) logic for reading csv-files by certain order. Esa From: Fabian Hueske Sent: Tuesday, May 8, 2018 2:00 PM To: Esa Heikkinen Cc: user@flink.apache.org Subject: Re: Reading csv-files in parallel Hi, the easiest approach is to read the CSV files linewise as regular text files

Re: Reading csv-files in parallel

2018-05-08 Thread Fabian Hueske
t; > > > Best, Esa > > > > *From:* Fabian Hueske > *Sent:* Monday, May 7, 2018 3:48 PM > *To:* Esa Heikkinen > *Cc:* user@flink.apache.org > *Subject:* Re: Reading csv-files in parallel > > > > Hi Esa, > > you can certainly read CSV files in p

RE: Reading csv-files in parallel

2018-05-08 Thread Esa Heikkinen
To: Esa Heikkinen Cc: user@flink.apache.org Subject: Re: Reading csv-files in parallel Hi Esa, you can certainly read CSV files in parallel. This works very well in a batch query. For streaming queries, that expect data to be ingested in timestamp order this is much more challenging, because you

Re: Reading csv-files in parallel

2018-05-07 Thread Fabian Hueske
Hi Esa, you can certainly read CSV files in parallel. This works very well in a batch query. For streaming queries, that expect data to be ingested in timestamp order this is much more challenging, because you need 1) read the files in the right order and 2) cannot split files (unless you guarante

Re: Reading csv-files

2018-03-01 Thread Fabian Hueske
ail.com] > *Sent:* Thursday, March 1, 2018 11:23 AM > > *To:* Esa Heikkinen > *Cc:* user@flink.apache.org > *Subject:* Re: Reading csv-files > > > > Hi Esa, > > IMO, the easiest approach would be to implement a custom source function > that reads the CSV files li

RE: Reading csv-files

2018-03-01 Thread Esa Heikkinen
Hi Should the custom source function be written by Java, but no Scala, like in that RideCleansing exercise ? Best, Esa From: Fabian Hueske [mailto:fhue...@gmail.com] Sent: Thursday, March 1, 2018 11:23 AM To: Esa Heikkinen Cc: user@flink.apache.org Subject: Re: Reading csv-files Hi Esa, IMO

Re: Reading csv-files

2018-03-01 Thread Fabian Hueske
ueske [mailto:fhue...@gmail.com] > *Sent:* Tuesday, February 27, 2018 11:27 PM > *To:* Esa Heikkinen > *Cc:* user@flink.apache.org > *Subject:* Re: Reading csv-files > > > > Yes, that is mostly correct. > You can of course read files in parallel, assign watermarks, and

RE: Reading csv-files

2018-02-28 Thread Esa Heikkinen
do not know better. I also tried Spark, but it also had its own problems. For example CEP is not good in Spark than in Flink. Best, Esa From: Fabian Hueske [mailto:fhue...@gmail.com] Sent: Tuesday, February 27, 2018 11:27 PM To: Esa Heikkinen Cc: user@flink.apache.org Subject: Re: Reading csv

Re: Reading csv-files

2018-02-27 Thread Fabian Hueske
Yes, that is mostly correct. You can of course read files in parallel, assign watermarks, and obtain a DataStream with correct timestamps and watermarks. If you do that, you should ensure that each parallel source tasks reads the files in the order of increasing timestamps. As I said before, you ca

Re: Reading csv-files

2018-02-27 Thread Esa Heikkinen
Hi Thanks for the answer. All csv-files are already present and they will not change during the processing. Because Flink can read many streams in parallel, i think it is also possbile to read many csv-files in parallel. From what i have understand, it is possible to convert csv-files to

Re: Reading csv-files

2018-02-27 Thread Fabian Hueske
Hi Esa, Reading records from files with timestamps that need watermarks can be tricky. If you are aware of Flink's watermark mechanism, you know that records should be ingested in (roughly) increasing timestamp order. This means that files usually cannot be split (i.e, need to be read by a single