May 2015 - users-list

Documenting date time functionality in MonetDB
by Robin Cijvat 22 May '15

22 May '15

I am currently working on documenting date/time functionality that exists in MonetDB and I have run into some problems/questions. I hope someone can help me out: 1) According to the Temporal Types page (https://www.monetdb.org/Documentation/SQLreference/Temporal), there should be a type 'daytime'. However, the following fails: create table t (b daytime);-> type (daytime) unknown in: "create table t (b daytime)" Does anyone know whether this feature has been removed or that this is a bug (or that I am perhaps missing something)? 2) Converting strings to dates works like a charm: *SELECT str_to_date('23-09-1987', '%d-%m-%Y');*-> 1987-09-23 But how about converting strings to times/timestamps: *SELECT str_to_date('11:40', '%H:%M');* -> null I can not seem to find any definitions of built in functions that take a string and produce anything other than a date. Thanks in advance! Robin PS: I am running the latest default branch on Ubuntu 14.04.

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division by zero
by Anthony Damico 22 May '15

22 May '15

i'm just curious/thinking out loud if anything can be done to prevent division by zero from de-railing a huge query? unlike most error messages, division by zero destroys a query *after* the bulk of the processing occurs - so you sit and wait and the command still fails, despite all the time and cpu revving. i assume it's impossible to check for this event *before* a query gets executed, but would it be possible to have a database option that essentially replaces zeroes with NULLs in the circumstances that this does occur so the query still returns the rest of the table? or would doing that be sloppy database management? so maybe this fails select 1 / 0 as x; but you change some setting and it auto-coerces everything under a division operator to select 1 / ( CASE WHEN value = 0 THEN NULL ELSE value END ) as x; that way you lose x but maybe not other columns? sorry if this is stupid..and thank you

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Re: users-list Digest, Vol 33, Issue 14
by Michael Helmke 19 May '15

19 May '15

Hi, Thank you for your reply. I am using mclient to do the inserts. For your question about the monetdb version, I get "MonetDB Database Server Toolkit v1.1 (Oct2014-SP3)" from the monetdb --version switch. If I insert "b\\\\c" that does work fine. And I tried doubling all of the backslashes which worked until I got unicode characters of the form: \\u03c1 for example. That case then doesn't work. Adding backslash escapes on the quotes in my second example didn't change anything. In the short term, I'm going to skip json and simply store strings. I'm also playing with the json parser in the code to do tests and see if I can find a simple fix or workaround there. Thank you, Michael Helmke > Date: Tue, 19 May 2015 08:46:29 +0200 (CEST) > From: Arjen de Rijke <Arjen.de.Rijke(a)cwi.nl> > To: Communication channel for MonetDB users <users-list(a)monetdb.org> > Subject: Re: Known issues with JSON field type? > Message-ID: <1281096997.870323.1432017989628.JavaMail.zimbra(a)cwi.nl> > Content-Type: text/plain; charset=utf-8 > > Hi Michael, > > Since \ is used for escaping characters and " is/can also be a string delimiter, using these within a json object that is inserted in a database, can be tricky. It might also depend on how you do the insertion, for example if you use mclient or if you use for example jdbc from code. > > How do you try to insert these records and what happens if you try something like this: > > insert into foo (jdata) values ('["a", "b\\\\c"]'); > > insert into foo (jdata) values ('{"abc": \"\"}'); > > And which version of monetdb are you using? > > Arjen de Rijke > > ----- Original Message ----- >> From: "Michael Helmke" <michael(a)visan.com> >> To: users-list(a)monetdb.org >> Sent: Tuesday, May 19, 2015 3:42:28 AM >> Subject: Known issues with JSON field type? > >> I am using MonetDB 11.19.9 and using a JSON field type in my database. I am new >> to MonetDB and experienced with SQL and databases. >> >> I find when I try to store some json strings that I think are valid json, the >> database complains on row insert. >> >> For example, the following don't work: >> >> insert into foo (jdata) values ('["a", "b\\c"]'); >> >> insert into foo (jdata) values ('{"abc": ""}'); >> >> The first problem is with the quoted backslash. The second problem is with the >> double quotes. If I remove the quoted backslash it works, likewise replace >> double quotes with null and it works. >> >> This is my table create: >> >> create table foo ( jdata json ); >> >> My read of the JSON spec is that this is legal JSON. Are there known issues >> with JSON support in MonetDB? >> >> Thank you, >> >> Michael Helmke >> _______________________________________________ >> users-list mailing list >> users-list(a)monetdb.org >> https://www.monetdb.org/mailman/listinfo/users-list >

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easiest way to coerce "?m/?d/yyyy" strings to a date in monetdb?
by Anthony Damico 19 May '15

19 May '15

hi, i have a VARCHAR column with dates like "1/1/2014" and also "12/31/2014" since there are no leading zeroes, the months and days are in different positions so i cannot use something like this to CAST it into a date type. CAST( SUBSTRING( x , 7 , 10 ) || '-' || SUBSTRING( x , 1 , 2 ) || '-' || SUBSTRING( x , 4 , 5 ) AS DATE ) AS y could someone offer advice to convert this string field to date in monetdb? thanks!!

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Known issues with JSON field type?
by Michael Helmke 19 May '15

19 May '15

I am using MonetDB 11.19.9 and using a JSON field type in my database. I am new to MonetDB and experienced with SQL and databases. I find when I try to store some json strings that I think are valid json, the database complains on row insert. For example, the following don't work: insert into foo (jdata) values ('["a", "b\\c"]'); insert into foo (jdata) values ('{"abc": ""}'); The first problem is with the quoted backslash. The second problem is with the double quotes. If I remove the quoted backslash it works, likewise replace double quotes with null and it works. This is my table create: create table foo ( jdata json ); My read of the JSON spec is that this is legal JSON. Are there known issues with JSON support in MonetDB? Thank you, Michael Helmke

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Re: Facing issues in implementing Embedded R in MonetDB-11.19.11
by Dimitar Nedev 15 May '15

15 May '15

Hi Vishal, Please try the following: separate the sources, build and installation directories, to avoid any overwriting files. Delete the old sources, build and installation directories and unpack the sources again. Once the sources and unpacked, make a directory called 'BUILD' in the sources dir. Go in the BUILD directory and run the configure script from there, also setting an installation location using the '--prefix' option, e.g.: ../configure --prefix=$HOME/monetdb-install --enable-optimize --enable-rintegratioin=yes Then go to '$HOME/monetdb-install' and run monetdbd from there: bin/monetdbd create dbfarm bin/monetdbd start dbfarm ... Do the same for the rest of the monetdb setup. I am asking you to do this, since I just tired the exact same setup on a clean Ubuntu Server 14.04.2 on VBox without any issues. Best regards, Dimitar > On 2015-May-15, at 12:00 , Vishal Virmani <virmani.vishal(a)gmail.com> wrote: > > Hi Dimitar > > I enabled R integration explicitly using monetdb set embed_r=true testdb1. > > Please find attached merovingian.log file generated for your reference, Dimitar i ran the following commands to check if monetdbd, monetdb and mclient are installed properly. > > The console output is generated are mentioned for your reference > > sudo monetdbd –version > > > > MonetDB Database Server v1.7 (Oct2014-SP3) > > > > sudo monetdb –version > > > > MonetDB Database Server Toolkit v1.1 (Oct2014-SP3) > > > > sudo mclient –version > > > > mclient, the MonetDB interactive terminal (Oct2014-SP3) support for command-line editing compiled-in character encoding UTF-8 > > > I think these are properly installed as can be seen from console outputs i mentioned for each of them. > > Kindly guide me to do the needful > > Regards > Vishal Virmani > +91 99108 47231 > @poisoncreed > > On Fri, May 15, 2015 at 5:07 AM, Vishal Virmani <virmani.vishal(a)gmail.com> wrote: > Hi Dimitar > > I enabled R integration explicitly using monetdb set embed_r=true testdb1. > > I have attached the log file for your reference, Dimitar i ran the following commands to check if monetdbd, monetdb and mclient are installed properly. > > The console output is generated are mentioned for your reference > > sudo monetdbd –version > > > > MonetDB Database Server v1.7 (Oct2014-SP3) > > > > sudo monetdb –version > > > > MonetDB Database Server Toolkit v1.1 (Oct2014-SP3) > > > > sudo mclient –version > > > > mclient, the MonetDB interactive terminal (Oct2014-SP3) support for command-line editing compiled-in character encoding UTF-8 > > > I think these are properly installed as can be seen from console outputs i mentioned for each of them. > > Kindly guide me to do the needful > > > > Regards > Vishal Virmani > +91 99108 47231 > @poisoncreed > > On Thu, May 14, 2015 at 12:23 PM, Dimitar Nedev <dimitar.nedev(a)monetdbsolutions.com> wrote: > Hi Vishal, > > Can you please attach the 'merovingian.log' file from the dbfarm directory? > > After step 11, you must enable the R integration for the newly created database, before starting it: > monetdb set embedr=true testdb1 > This in unlikely to be the cause of the "failed to open up a communication channel" error, but is needed to actually enable the R integration. > > Also, it is not necessary to configure, make, install, create dbfarms and start databases with sudo. A regular user should also be able to do that, as long as he has sufficient write access permissions for the target directories. Please try that as well. > > A side note: If you want to get better performance from your database (and not planning to attach a debugger to your it), it's recommended to set the '--enable-optimize' option when configuring the build at step 6. > > Best regards, > Dimitar > > > On 2015-May-14, at 01:49 , Vishal Virmani <virmani.vishal(a)gmail.com> wrote: > > > > Hi Hannes > > > > As you suggested i checked, i am not having any multiple installation of MonetDB. > > > > Further i have done a fresh installation. I am including the messages in the merovingian file as well for your reference. > > > > Steps followed were > > > > Step 1 : I created a clean VM with Ubuntu 14.04 server. > > > > Step 2: Installed R-3.2.0 from source files. I checked the R environment it is working fine. > > > > Step 3: Downloaded MonetDB source files from http://dev.monetdb.org/downloads/sources/Oct2014-SP3/MonetDB-11.19.11.tar.xz <http://dev.monetdb.org/downloads/sources/Oct2014-SP3/MonetDB-11.19.11.tar.xz> > > > > Step 4: Created an empty directory sourcefiles in which i downloaded MonetDB-11.19.11-tar.xz > > > > Step 5: Unpacked the source files > > > > Step 6: Executed the command sudo ./configure --enable-rintegratioin=yes > > > > The result of executing the above command generated the following output: > > > > Output of running configure command > > > > Enabled/disabled build options: > > > > strict is disabled (by default) > > assert is disabled (by default) > > debug is disabled (by default) > > optimize is disabled (by default) > > developer is disabled (by default) > > instrument is disabled (by default) > > profile is disabled (by default) > > > > > > Enabled/disabled components: > > > > gdk is enabled > > monetdb5 is enabled > > sql is enabled > > geom is disabled (geos library required for geom library) > > gsim is disabled (gsl library not found) > > fits is disabled (cfitsio library not found) > > jsonstore is disabled (by default) > > microhttpd is disabled (by default) > > rdf is disabled (by default) > > rintegration is enabled > > datacell is disabled (by default) > > odbc is disbaled (unixODBC library required for ODBC driver) > > jdbc is disabled (ant is required to build MonetDB JDBC) > > control is disabled (ant is required to build merovingian control library) > > testing is enabled > > > > > > > > > > Step 7 : Executed sudo make and make install respectively. They are working fine. > > > > > > Step 8 : Checked sudo mserver5 --version , it gave the the desired output > > > > Step 9: Created a dbfarm using the command sudo monetdbd create /mydbfarm > > > > Step 10 Started the dbfarm by running sudo monetdbd start /mydbfarm, this also get executed successfully > > > > Step 11. Created a sample database testdb1 using command : sudo monetdb create testdb1. This also gets executed fine. > > > > Step 12 Upon execution of command sudo monetdb start testdb1, it fails showing me an error in merovingian file and on console i am generating following output > > > > starting database 'testdb1'...FAILED > > start: starting 'testdb1' failed: datbase 'testdb1' started up, but failed to open up a communication channel. > > > > > > Looking forward to your suggestion > > > > Regards > > Vishal Virmani > > +91 99108 47231 > > > > > > > > > > Regards > > Vishal Virmani > > +91 99108 47231 > > @poisoncreed > > > > On Tue, May 12, 2015 at 3:30 PM, <users-list-request(a)monetdb.org <mailto:users-list-request@monetdb.org>> wrote: > > Send users-list mailing list submissions to > > users-list(a)monetdb.org <mailto:users-list@monetdb.org> > > > > To subscribe or unsubscribe via the World Wide Web, visit > > https://www.monetdb.org/mailman/listinfo/users-list <https://www.monetdb.org/mailman/listinfo/users-list> > > or, via email, send a message with subject or body 'help' to > > users-list-request(a)monetdb.org <mailto:users-list-request@monetdb.org> > > > > You can reach the person managing the list at > > users-list-owner(a)monetdb.org <mailto:users-list-owner@monetdb.org> > > > > When replying, please edit your Subject line so it is more specific > > than "Re: Contents of users-list digest..." > > > > > > Today's Topics: > > > > 1. Facing issues in implementing Embedded R in MonetDB-11.19.11 > > (Vishal Virmani) > > 2. Re: Facing issues in implementing Embedded R in > > MonetDB-11.19.11 (Hannes M?hleisen) > > > > > > ---------------------------------------------------------------------- > > > > Message: 1 > > Date: Tue, 12 May 2015 05:29:13 +0530 > > From: Vishal Virmani <virmani.vishal(a)gmail.com <mailto:virmani.vishal@gmail.com>> > > To: users-list(a)monetdb.org <mailto:users-list@monetdb.org> > > Subject: Facing issues in implementing Embedded R in MonetDB-11.19.11 > > Message-ID: > > <CA+dsbSFzWfqd=GEuAP17rqVPCfVWySShJa+rnyUPHkNbvrjbLw(a)mail.gmail.com <mailto:GEuAP17rqVPCfVWySShJa%2BrnyUPHkNbvrjbLw@mail.gmail.com>> > > Content-Type: text/plain; charset="utf-8" > > > > Hi > > > > I am implementing Embedded R in MonetDB version 11.19.11. My environment is > > VM with Ubuntu 14.04 Server. I have build MonetDB from source and R as well > > as from source. > > Running the command sudo mserver5 --version shows me the desired output. > > > > When i try to invoke a database using sudo monetdb start testdb1 command, > > where testdb1 is a database i successfully created, it repeatedly throws up > > an error...database 'testdb1' started up, but failed to open up a > > communication channel. > > > > Upon checking the associated merovingian log file i see further messages > > saying the object code to rapi.prelude missing. > > > > Any way to resolve this...? > > > > > > Regards > > Vishal Virmani > > @poisoncreed > >

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Facing issues in implementing Embedded R in MonetDB-11.19.11
by Vishal Virmani 14 May '15

14 May '15

Hi Hannes As you suggested i checked, i am not having any multiple installation of MonetDB. Further i have done a fresh installation. I am including the messages in the merovingian file as well for your reference. Steps followed were Step 1 : I created a clean VM with Ubuntu 14.04 server. Step 2: Installed R-3.2.0 from source files. I checked the R environment it is working fine. Step 3: Downloaded MonetDB source files from http://dev.monetdb.org/downloads/sources/Oct2014-SP3/MonetDB-11.19.11.tar.xz Step 4: Created an empty directory sourcefiles in which i downloaded MonetDB-11.19.11-tar.xz Step 5: Unpacked the source files Step 6: Executed the command sudo ./configure --enable-rintegratioin=yes The result of executing the above command generated the following output: Output of running configure command Enabled/disabled build options: strict is disabled (by default) assert is disabled (by default) debug is disabled (by default) optimize is disabled (by default) developer is disabled (by default) instrument is disabled (by default) profile is disabled (by default) Enabled/disabled components: gdk is enabled monetdb5 is enabled sql is enabled geom is disabled (geos library required for geom library) gsim is disabled (gsl library not found) fits is disabled (cfitsio library not found) jsonstore is disabled (by default) microhttpd is disabled (by default) rdf is disabled (by default) rintegration is enabled datacell is disabled (by default) odbc is disbaled (unixODBC library required for ODBC driver) jdbc is disabled (ant is required to build MonetDB JDBC) control is disabled (ant is required to build merovingian control library) testing is enabled Step 7 : Executed sudo make and make install respectively. They are working fine. Step 8 : Checked sudo mserver5 --version , it gave the the desired output Step 9: Created a dbfarm using the command sudo monetdbd create /mydbfarm Step 10 Started the dbfarm by running sudo monetdbd start /mydbfarm, this also get executed successfully Step 11. Created a sample database testdb1 using command : sudo monetdb create testdb1. This also gets executed fine. Step 12 Upon execution of command sudo monetdb start testdb1, it fails showing me an error in merovingian file and on console i am generating following output starting database 'testdb1'...FAILED start: starting 'testdb1' failed: datbase 'testdb1' started up, but failed to open up a communication channel. Looking forward to your suggestion Regards Vishal Virmani +91 99108 47231 Regards Vishal Virmani +91 99108 47231 @poisoncreed On Tue, May 12, 2015 at 3:30 PM, <users-list-request(a)monetdb.org> wrote: > Send users-list mailing list submissions to > users-list(a)monetdb.org > > To subscribe or unsubscribe via the World Wide Web, visit > https://www.monetdb.org/mailman/listinfo/users-list > or, via email, send a message with subject or body 'help' to > users-list-request(a)monetdb.org > > You can reach the person managing the list at > users-list-owner(a)monetdb.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of users-list digest..." > > > Today's Topics: > > 1. Facing issues in implementing Embedded R in MonetDB-11.19.11 > (Vishal Virmani) > 2. Re: Facing issues in implementing Embedded R in > MonetDB-11.19.11 (Hannes M?hleisen) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Tue, 12 May 2015 05:29:13 +0530 > From: Vishal Virmani <virmani.vishal(a)gmail.com> > To: users-list(a)monetdb.org > Subject: Facing issues in implementing Embedded R in MonetDB-11.19.11 > Message-ID: > <CA+dsbSFzWfqd= > GEuAP17rqVPCfVWySShJa+rnyUPHkNbvrjbLw(a)mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > Hi > > I am implementing Embedded R in MonetDB version 11.19.11. My environment is > VM with Ubuntu 14.04 Server. I have build MonetDB from source and R as well > as from source. > Running the command sudo mserver5 --version shows me the desired output. > > When i try to invoke a database using sudo monetdb start testdb1 command, > where testdb1 is a database i successfully created, it repeatedly throws up > an error...database 'testdb1' started up, but failed to open up a > communication channel. > > Upon checking the associated merovingian log file i see further messages > saying the object code to rapi.prelude missing. > > Any way to resolve this...? > > > Regards > Vishal Virmani > @poisoncreed >

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Reclaiming Hard Disk Space occupied by Intermidiates
by Ashish Kumar Singh 12 May '15

12 May '15

Dear List, I understand from monetdb documentation that intermediates can be materialised in to hard disk in certain scenarios. In our scenario we were running out of disk space infrequently , Is there any way we can suggest monetdb to get rid of all intermediates? Any pointers on this will be really helpful. Regards, Ashish Kumar Singh Mobile: +91-9972045095 Skype: toashishk(a)gmail.com

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Facing issues in implementing Embedded R in MonetDB-11.19.11
by Vishal Virmani 12 May '15

12 May '15

Hi I am implementing Embedded R in MonetDB version 11.19.11. My environment is VM with Ubuntu 14.04 Server. I have build MonetDB from source and R as well as from source. Running the command sudo mserver5 --version shows me the desired output. When i try to invoke a database using sudo monetdb start testdb1 command, where testdb1 is a database i successfully created, it repeatedly throws up an error...database 'testdb1' started up, but failed to open up a communication channel. Upon checking the associated merovingian log file i see further messages saying the object code to rapi.prelude missing. Any way to resolve this...? Regards Vishal Virmani @poisoncreed

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Problem selecting entries newer than a certain date
by Maarten Sander 01 May '15

01 May '15

Hi everyone, I’m probably missing something, but it seems that I cannot select entries that are newer than a given timestamp. Below are my attempts and the schema of the table. Any help would be greatly appreciated! Regards, Maarten sql>SELECT completed FROM "reporting"."transactions" WHERE completed >= '2015-04-10 00:00:00.0000' ORDER BY completed DESC; +-----------+ | completed | +===========+ +-----------+ 0 tuples (0.595ms) sql>SELECT completed FROM "reporting"."transactions" WHERE completed >= CAST('2015-04-10 00:00:00.0000' AS TIMESTAMP) ORDER BY completed DESC; +-----------+ | completed | +===========+ +-----------+ 0 tuples (0.328ms) sql>SELECT completed FROM "reporting"."transactions" ORDER BY completed DESC LIMIT 10; +----------------------------+ | completed | +============================+ | 2015-04-10 11:50:22.051000 | | 2015-04-10 10:55:50.039000 | | 2015-04-09 09:41:13.023000 | | 2015-04-09 09:39:09.079000 | | 2015-04-09 09:35:56.085000 | | 2015-04-08 12:55:13.007000 | | 2015-04-08 12:37:07.002000 | | 2015-04-08 12:28:22.000000 | | 2015-04-08 12:25:25.052000 | | 2015-04-07 21:59:59.099000 | +----------------------------+ 10 tuples (0.683ms) sql>\d "reporting"."transactions" CREATE TABLE "reporting"."transactions" ( "id" CHAR(36) NOT NULL, "status" VARCHAR(25) NOT NULL, "created" TIMESTAMP NOT NULL, "completed" TIMESTAMP, "currency" CHAR(3) NOT NULL, "amount" BIGINT NOT NULL, "balance" VARCHAR(25) NOT NULL, "payment_method" VARCHAR(50) NOT NULL, "fee_currency" CHAR(3), "fee_amount" BIGINT, "order_id" CHAR(36) NOT NULL, "order_status" VARCHAR(25) NOT NULL, "project_id" CHAR(36) NOT NULL, "merchant_id" CHAR(36) NOT NULL, CONSTRAINT "transactions_id_pkey" PRIMARY KEY ("id") );

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