- users-list - monetdb.org

Plan for feature, external REMOTE table as a plugin (hadoop, jdbc, odbc, etc).
by Aris Setyawan 17 Oct '15

17 Oct '15

Hi, The key value of monetdb is it's parallel query. That many other opensource DBMS doesn't support it. But monetdb have it in the core engine. It is mean a mature feature. Having ability load (on the fly) any other DBMS data using external REMOTE table, and then query them using monetdb parallel query, will attract big community and contribution (as a plugin). The dbms, for example: jdbc, odbc, mysql, postgresql, hadoop, hive, or any commercial dbms. Any dbms which doesn't have parallel query feature, will benefit from this. Any plan for this feature? Regards, Aris

1 0

SQL join involving remote table.
by Aris Setyawan 17 Oct '15

17 Oct '15

Hi, According to https://www.monetdb.org/Documentation/Cookbooks/SQLrecipes/DistributedQuery… It is said that, "Queries involving remote tables are automatically split into subqueries by the master database and executed on remote databases.". I think this scenario: I have 3 server, one master server and two worker servers. I have 2 tables, A (big one, a fact table) and B (small one, a dimension table). A is a merge table of 2 remote tables. The remote table exist in two worker servers. B is a dimension table, that I'm not sure, on which server, I should place it on. And I will do queries, that join A and B. On which server, I should place table B to achieve distributed query processing? Is table B should be replicated on all remote table? Thanks, -Aris

2 2

JDBC Connection to a schema
by Vijay Krishna 16 Oct '15

16 Oct '15

Hi, I am trying to connect a schema within a database directly through JDBC with the following Java code. Connection con = DriverManager.getConnection( > "jdbc:monetdb://localhost/testUser", "monetdb", "monetdb"); > con.setSchema("schema1"); But this throws the following exception. > Exception in thread "main" java.sql.SQLException: syntax error, > unexpected '=' in: "set schema =" > at nl.cwi.monetdb.jdbc.MonetConnection$ResponseList.executeQuery( > MonetConnection.java:2525) > at nl.cwi.monetdb.jdbc.MonetConnection$ResponseList.processQuery( > MonetConnection.java:2273) > at nl.cwi.monetdb.jdbc.MonetStatement.internalExecute( > MonetStatement.java:497) > at nl.cwi.monetdb.jdbc.MonetStatement.execute(MonetStatement.java:338) > at nl.cwi.monetdb.jdbc.MonetStatement.executeUpdate( > MonetStatement.java:533) > at nl.cwi.monetdb.jdbc.MonetConnection.setSchema(MonetConnection.java:1267 > ) > at batcave.Monet.main(Monet.java:11) Is it really possible to connect to a specific schema? Or the only option is to query as "schemaName.tableName" ??? Thanks & Regards, Vijayakrishna.P. Mobile : (+91) 9500402305.

3 3

Baseline Performance Expectation?
by Paul Ramsey 15 Oct '15

15 Oct '15

Hi all, I’ve loaded a relatively small table (I think) of 30M records, 7 columns, and I’m doing some test queries summarizing and filtering the table, like this: select vendor_id, count(*) from taxi where geohash like '90efbc6a6fc%’ group by vendor_id; On my 4-core iMac, the CPU doesn’t get very hot (20% on top, so it’s not even lighting up one of the four CPUs) , but it’s hard to tell since the return time is only 2.5 second. Is that as fast as things will get? I doubled the table size and query times more-or-less doubled. I was just hoping to get query times in the < 1s range. Thanks, P -- Paul Ramsey Solutions Engineer CartoDB—Map Your World's Data 143 Roebling St 2A, New York, 11211, USA T: +1.917.463.3232 Skype: pwramsey3 W: www.cartodb.com Live sessions to learn CartoDB

2 1

Finding the current schema
by Enzo 14 Oct '15

14 Oct '15

Is there a query that would let me know what is the current schema in my db? E.g. I would expect as a response either sys (if I haven't set any schema), or foo (if I've set the schema foo). Kindest regards Enzo enzo(a)smartinsightsfromdata.com

1 0

Support for UUIDs in R and Python
by Doug Service 09 Oct '15

09 Oct '15

Hello everyone, I discovered this morning that the UUID type is not supported in MonetDB.R package on CRAN Error in monetdbRtype(info$types[i]) : Unknown DB type UUID and UUIDs are not support in the Python API which I installed from source File "/usr/local/lib/python3.4/dist-packages/monetdb/sql/pythonize.py", line 132, in convert raise ProgrammingError("type %s is not supported" % type_code) monetdb.exceptions.ProgrammingError: type uuid is not supported Will UUIDs be supported in R and Python in a future release? We use R extensively for statistical analysis on our data and would also like to use Python in certain cases. Doug

1 0

Re UUID and new crash problem
by Doug Service 09 Oct '15

09 Oct '15

Hello Stefan, I modified the uuid.mal file in the lib directory and that all works great for a small sample test from mclient. Thanks! Now I have run into a problem where the server crashes when I try to insert into one of the tables, though inserts in other tables work fine. I do not think this problem has anything with UUIDS as the table I am inserting into does not use UUIDS and I can do inserts into tables that have uuid columns. This insert that causes the crash worked fine on the last version of our schema that did not use UUIDs. I have a small database from msqldump and an insert statement that causes the server to crash consistently. However, I do not see any way to add attachments to a bug report on the tracker. Is there a way to do this? Is there any other information I can collect that would be useful in a bug report? Here is the monetdb log which shows a sigsegv. Doug 2015-10-06 16:02:19 MSG quantbox[3433]: # MonetDB 5 server v11.21.5 "Jul2015" 2015-10-06 16:02:19 MSG quantbox[3433]: # Serving database 'quantbox', using 4 threads 2015-10-06 16:02:19 MSG quantbox[3433]: # Compiled for x86_64-pc-linux-gnu/64bit with 64bit OIDs and 128bit integers dynamically linked 2015-10-06 16:02:19 MSG quantbox[3433]: # Found 1.907 GiB available main-memory. 2015-10-06 16:02:19 MSG quantbox[3433]: # Copyright (c) 1993-July 2008 CWI. 2015-10-06 16:02:19 MSG quantbox[3433]: # Copyright (c) August 2008-2015 MonetDB B.V., all rights reserved 2015-10-06 16:02:19 MSG quantbox[3433]: # Visit http://www.monetdb.org/ for further information 2015-10-06 16:02:19 MSG quantbox[3433]: # Listening for UNIX domain connection requests on mapi:monetdb:///var/lib/monetdb/quantbox/.mapi.sock 2015-10-06 16:02:19 MSG quantbox[3433]: # Start processing logs sql/sql_logs version 52200 2015-10-06 16:02:19 MSG quantbox[3433]: # Start reading the write-ahead log 'sql_logs/sql/log.4' 2015-10-06 16:02:19 MSG quantbox[3433]: # Finished reading the write-ahead log 'sql_logs/sql/log.4' 2015-10-06 16:02:19 MSG quantbox[3433]: # Finished processing logs sql/sql_logs 2015-10-06 16:02:19 MSG quantbox[3433]: # MonetDB/SQL module loaded 2015-10-06 16:02:19 MSG merovingian[809]: proxying client 10.1.10.101:40633 for database 'quantbox' to mapi:monetdb:///var/lib/monetdb/quantbox/.mapi.sock?database=quantbox 2015-10-06 16:02:19 MSG merovingian[809]: target connection is on local UNIX domain socket, passing on filedescriptor instead of proxying 2015-10-06 16:05:19 MSG merovingian[809]: proxying client (local) for database 'quantbox' to mapi:monetdb:///var/lib/monetdb/quantbox/.mapi.sock?database=quantbox 2015-10-06 16:05:19 MSG merovingian[809]: target connection is on local UNIX domain socket, passing on filedescriptor instead of proxying 2015-10-06 16:05:27 MSG merovingian[809]: proxying client (local) for database 'quantbox' to mapi:monetdb:///var/lib/monetdb/quantbox/.mapi.sock?database=quantbox 2015-10-06 16:05:27 MSG merovingian[809]: target connection is on local UNIX domain socket, passing on filedescriptor instead of proxying 2015-10-06 16:05:48 MSG merovingian[809]: database 'quantbox' (3433) was killed by signal SIGSEGV 2015-10-06 16:05:59 MSG merovingian[809]: starting database 'quantbox', up min/avg/max: 0s/0s/0s, crash average: 1.00 0.30 0.10 (3-0=3) 2015-10-06 16:06:00 MSG quantbox[3532]: arguments: /usr/bin/mserver5 --dbpath=/var/lib/monetdb/quantbox --set merovingian_uri=mapi:monetdb://qbdb:42000/quantbox --set mapi_open=false --set mapi_port=0 --set mapi_usock=/var/lib/monetdb/quantbox/.mapi.sock --set monet_vault_key=/var/lib/monetdb/quantbox/.vaultkey --set gdk_nr_threads=4 --set max_clients=64 --set sql_optimizer=default_pipe --set monet_daemon=yes

3 4

Problems implementing java jdbc
by Federico G Agripa 09 Oct '15

09 Oct '15

Hi, i'm having some issues implementing the java jdbc with a grails-app. Grails is a framework that runs on the jvm, allowing you to write all your code in java if you want. I'm using exactly the code you provide on your web page but it isn't recognizing a proper driver to connect to monet at runtime. I also tried to search some repo that provides a plugin or extension that allows me to use but i get the same error (the only one i found was www.clojars.com/monetdb) is there any example of a driver implementation you can provide or any forum to forward this? Thanks in advice

3 3

Grails integration
by Federico G Agripa 09 Oct '15

09 Oct '15

Hello, i'm working on a grails plugin to easily integrate with monetDB. So I would like to here what functionalities will be useful to you guys because I want it to be useful to all of you to. I'm implementing it from the monet jar 2.17 and I hope to have it up in grails plugins as soon as possible. Btw any collaboration will be really welcome Regards

1 0

Regex support
by imad hajj chahine 08 Oct '15

08 Oct '15

Hi, Monetdb is using pcre library for regular expression support, and using this function we can allow SQL to use the regex library: CREATE FUNCTION "pcre_replace" (origin string, pat string, repl string,flags string) RETURNS string EXTERNAL NAME pcre."replace"; I want to use regex for date conversion to the format supported by monetdb (yyyy-MM-dd), I have the following format dd/MM/yyyy, and i am trying to run the following with no success: select pcre_replace('15/10/2015', '^(3[01]|[12][0-9]|0?[1-9])/(1[012]|0?[1-9])/([0-9]{4})$', '\\3-\\2-\\1', 'i') select pcre_replace('15/10/2015', '^(3[01]|[12][0-9]|0?[1-9])/(1[012]|0?[1-9])/([0-9]{4})$', '{3}-{2}-{1}', 'i') select pcre_replace('15/10/2015', '^(?<day>3[01]|[12][0-9]|0?[1-9])/(?<month>1[012]|0?[1-9])/(?<year>[0-9]{4})$', '\\k<year>-\\k<month>-\\k<day>', 'i') My question is, is backreference supported in the replacement string; if yes, whats is the right syntax to use to reference the detected groups, if no, is there a clever way then using substring? Thanks

3 6

windows function
by imad hajj chahine 07 Oct '15

07 Oct '15

Hi, Since monetdb support window RANK functions, is it possible to extend the sql library to support also window aggregate function like SUM, AVG ... useful for running total and moving average. Any plan to support this in the near future or the implementation is easy to be done with user defined functions. Thanks.

2 4

UUIDs in MonetDB
by Doug Service 01 Oct '15

01 Oct '15

The documentation at https://www.monetdb.org/Documentation/Manuals/SQLreference/UUItype indicates that a UUID type is supported in MonetDB and gives the example select uuid(); +--------------------------------------+ | uuid | +======================================+ | 65950c76-a2f6-4543-660a-b849cf5f2453 | +--------------------------------------+ which appears to output from mclient. When I try the same with mclient I receive auto commit mode: on sql>select uuid(); SELECT: no such operator 'uuid' mapi.h only shows support for the following types #define MAPI_AUTO 0 /* automatic type detection */#define MAPI_TINY 1#define MAPI_UTINY 2#define MAPI_SHORT 3#define MAPI_USHORT 4#define MAPI_INT 5#define MAPI_UINT 6#define MAPI_LONG 7#define MAPI_ULONG 8#define MAPI_LONGLONG 9#define MAPI_ULONGLONG 10#define MAPI_CHAR 11#define MAPI_VARCHAR 12#define MAPI_FLOAT 13#define MAPI_DOUBLE 14#define MAPI_DATE 15#define MAPI_TIME 16#define MAPI_DATETIME 17#define MAPI_NUMERIC 18 Is it possible to get MonetDB to generate UUIDs and how is the type supported in mapi. Thanks Doug Service

4 8

R aggregation fails when input is exactly 200K tuples
by Roberto Cornacchia 01 Oct '15

01 Oct '15

Hi, I have a suspect failure at exactly 200K tuples in input. I declared a simple aggregate on two columns (here it doesn't aggregate, for simplicity, it just returns 42). START TRANSACTION; CREATE table test (customer int, d string, n int); INSERT INTO test VALUES(1,'2015-01-01', 100); INSERT INTO test VALUES(1, '2015-01-02', 100); INSERT INTO test VALUES(2, '2015-01-03', 100); INSERT INTO test VALUES(2, '2015-01-01', 100); INSERT INTO test VALUES(2, '2015-01-02', 100); CREATE AGGREGATE sow(d string, n int) RETURNS DOUBLE LANGUAGE R { # aggregation function is constant, not important here sow_aggr <- function(df) { 42.0 } df <- cbind(d,n) as.vector(by(df, aggr_group, sow_aggr)) }; select customer, sow(d,n) from test group by customer; ROLLBACK; +----------+--------------------------+ | customer | L1 | +==========+==========================+ | 1 | 42 | | 2 | 42 | +----------+--------------------------+ The result is what I had expected. That is true until table test is long 199999 tuples. When it's exactly 200000 tuples, I get: Error running R expression. Error message: Error in tapply(seq_len(200000L), list(INDICES = c(0, 1, 2, 3, 4, 5, 6, : arguments must have same length Calls: as.data.frame ... by.data.frame -> structure -> eval -> eval -> tapply I checked the vector aggr_group, and indeed it is not 200000 long, as it should be. Instead, it is just one longer than then number of distinct values for customer (the grouping column). Any thought? Roberto

2 3

COPY INTO string attribute containing single quote, succeed in Jan2014-SP2, fail in Jul2015
by Constantine Feng 30 Sep '15

30 Sep '15

Dear all, I am trying to bulk load the TPC-DS database benchmark into MonetDB. One of the data file "customer.csv" contains data in this format: 27|AAAAAAAALBAAAAAA|111621|835|16096|2450611|2450581|Dr.|Shawn|Prather|N|7|3|1972|PUERTO RICO||Shawn.Prather(a)8BusRYegn6.org|2452353 28|AAAAAAAAMBAAAAAA|889961|897|183480|2452615|2452585|Miss|Edith|Hernandez|Y|17|8|1959|CÔTE D'IVOIRE||Edith.Hernandez(a)BNHL0k.com|2452631 Note in the second row, there is a string attribute containing a single quote. And I use the below command to load it: COPY INTO customer from 'path/to/customer.csv' USING DELIMITERS '|','\n' NULL AS ''; I have two machines with two installations: one installed last year via Ubuntu apt-get, "monetdb version" shows "MonetDB Database Server Toolkit v1.1 (Jan2014-SP2)" the other recently follows the instructions here: https://www.monetdb.org/downloads/deb/ (Ubuntu), "MonetDB Database Server Toolkit v1.1 (Jul2015)" Somehow the loading succeeded in the former but failed in the latter. Is it due to some version difference? How can I fix it? Error: field 15 expecting varchar(15) 'CÔTE D'IVOIRE' Thanks in advance. - Neo

2 1

Strange characters with ODBC driver
by Dennis Pallett 28 Sep '15

28 Sep '15

Hi all, We're trying to use MonetDB together with SAP Business Objects using the ODBC driver but we're getting some strange results when using the table browser. The names of the schema's seem to be all mangled up (see attached screenshot). Any ideas what might be wrong? It works fine with the JDBC driver btw. Any advantages/disadvantages with both drivers? Best regards, Dennis Pallett

2 2

Version vs release naming schemes
by Eyal Rozenberg 28 Sep '15

28 Sep '15

What's the relation between the Month+Year release naming scheme (e.g. Jul2015, Oct2014-SP2) and the numeric versions (e.g. 11.19.9)? The website has a release history page: https://www.monetdb.org/Documentation/UserGuide/ReleaseNotes But I haven't found a page discussing the numeric version numbers. I'm not even sure the X.Y.Z format means version.subversion.subsubversion ... Eyal

2 1

Jul2015 not availbale for debian Wheezy
by imad hajj chahine 28 Sep '15

28 Sep '15

Hi, I am trying to upgrade my installation on debian from 11.19 to 11.21, i cant find the Jul2015 in the https://www.monetdb.org/downloads/deb/dists/wheezy/monetdb/binary-amd64/ and the apt-get is pointing to the 11.19.15 version, any idea how to get the latest release. Thank you

2 1

Issue importing certain character combinations
by andy.barlow＠datum360.com 25 Sep '15

25 Sep '15

I filed a bug earlier, the gist of which is below but perhaps there is some setting or flag I am missing when importing? If your import file contains a number of character combinations, such as \560, \561, \700 and probably lots of others, the copy into fails with a message like: Failed to import table line 5 field 1 'varchar(20)' expected in 'FIVE\700' Reproducible: Always Steps to Reproduce: 1. create table test (test varchar(20)); 2. create a load file test.txt with the following: ONE TWO THREE FOUR FIVE\700 3. copy into test from 'test.txt' using delimiters '\t','\n'; 4. fails with message: Failed to import table line 5 field 1 'varchar(20)' expected in 'FIVE\700' Actual Results: Failed to import table line 5 field 1 'varchar(20)' expected in 'FIVE\700' Expected Results: should import OK, the character combinations are valid Andy Barlow Datum360

1 1

Re: Disk space running out
by scArcer 24 Sep '15

24 Sep '15

"create table" and "insert data" are separate. And the disk is consumed by queries. because when I finished data loading, it was, only 3~4G. Thank you for the link. I will try restart server to see if monetdb can unlink these files too. I execute queries in auto commit mode, should I control transactions myself? ------------------ Original ------------------ From: "Guillaume Savary";<guillaume.savary(a)securactive.net>; Date: Thu, Sep 24, 2015 02:30 PM To: "Communication channel for MonetDB users"<users-list(a)monetdb.org>; Cc: "scArcer"<53308768(a)qq.com>; Subject: Re: Disk space running out Hi, Are you repeating this "create table + insert data" multiple times on this disk? Because there is a bug on the BAT files which are never freed : https://www.monetdb.org/bugzilla/show_bug.cgi?id=3802 Work around : try to do the "create table" in an other transaction than the "insert data". Le 24/09/2015 08:17, scArcer a écrit : Here is my situation. I create a table A, load about 3~4G data into it. Then a lot of queries are executed, making it using disk up to 1T. [hadoop@falco001-bi-30-141 data3]$ du -sh monetdb/ 1.1T monetdb/ and when I try to execute new query, I got this error: sql>select * from ods.attr_user_c_profile limit 10; could not allocate space for GDKsave: error -1 on: name=06/62/66261, ext=theap, mode=0 !OS: No space left on device HEAPextend: failed to extend to 983040 for 06/62/66261.theap: h->storage == STORE_MEM && can_map && fd >= 0 && HEAPsave_intern() < 0 ------------------ Original ------------------ From: "Martin Kersten";<martin.kersten(a)cwi.nl>; Date: Thu, Sep 24, 2015 02:03 PM To: "users-list"<users-list(a)monetdb.org>; Subject: Re: Disk space running out On 24/09/15 06:04, scArcer wrote: > Hi, I'm facing the problem of disk space running out. > Since monetdb will store the query intermediates into the disk when the memory is not enough to hold them all, I'm wondering that does monetdb will automatically free the disk space? > And if it doesn't, how can I do it manually? > > Hi It will release disk space as soon as possible. > _______________________________________________ > users-list mailing list > users-list(a)monetdb.org > https://www.monetdb.org/mailman/listinfo/users-list > _______________________________________________ users-list mailing list users-list(a)monetdb.org https://www.monetdb.org/mailman/listinfo/users-list _______________________________________________ users-list mailing list users-list(a)monetdb.org https://www.monetdb.org/mailman/listinfo/users-list -- Guillaume Savary Securactive R&D

1 0

Disk space running out
by scArcer 24 Sep '15

24 Sep '15

Hi, I'm facing the problem of disk space running out.Since monetdb will store the query intermediates into the disk when the memory is not enough to hold them all, I'm wondering that does monetdb will automatically free the disk space? And if it doesn't, how can I do it manually?

3 4

monetdb cluster on EC2
by imad hajj chahine 23 Sep '15

23 Sep '15

Hi, As per this link https://www.monetdb.org/pipermail/users-list/2013-August/006744.html, to be able to have monetdb cluster to work in ec2, a VPN must be used to connect the nodes. Following this link: https://www.buckhill.co.uk/blog/how-to-enable-broadcast-and-multicast-on-am…, i configured the VPN between the cluster nodes. Now for each node I have the eth0 and edge0 network interface, when i start monetdbd it directly bind to the eth0 interface, thats why i suppose the discover is not working. Any idea how to start monetdbd and bind to the interface used for VPN to be able to use TCP broadcast hence discover the other nodes. Any help will be appreciated. Thank You.

1 0

if i run these commands in R, mserver dies.. any ideas how to fix? thanks
by Anthony Damico 22 Sep '15

22 Sep '15

# MonetDB 5 server v11.21.3 "Jul2015" # Serving database 'marketscan', using 4 threads # Compiled for x86_64-pc-winnt/64bit with 64bit OIDs dynamically linked # Found 64.000 GiB available main-memory. # Copyright (c) 1993-July 2008 CWI. # Copyright (c) August 2008-2015 MonetDB B.V., all rights reserved # Visit http://www.monetdb.org/ for further information # Listening for connection requests on mapi:monetdb://127.0.0.1:49700/ # Start processing logs sql/sql_logs version 52200 # Start reading the write-ahead log 'sql_logs\sql\log.211' # Finished reading the write-ahead log 'sql_logs\sql\log.211' !ERROR: log_sequence_: write failed # Finished processing logs sql/sql_logs # MonetDB/SQL module loaded > ========================= > pid <- monetdb.server.start( batfile ) > dbname <- "marketscan" > dbport <- 49700 > monet.url <- paste0( "monetdb://localhost:" , dbport , "/" , dbname ) > db <- dbConnect( MonetDB.R() , monet.url , wait = TRUE ) Server not ready(cannot open the connection), retrying (ESC or CTRL+C to abort) > dbListTables(db) Error in .local(conn, statement, ...) : Unable to execute statement 'select schemas.name as sn, tables.name as tn from sys.tables join sys.schemas on tables.schema_id=sc...'. Server says 'ERROR: BBPdir_subcommit: Syncing BBP.dir file failed' [#GDKerror:]. > dbListTables(db) Error in .local(conn, statement, ...) : Unable to execute statement 'select schemas.name as sn, tables.name as tn from sys.tables join sys.schemas on tables.schema_id=sc...'. Server says 'ERROR: GDKsave: error on: name=06\651, ext=timprints, mode=0' [#GDKerror:]. > dbListTables(db) [1] "ccaea" "ccaed" "ccaef" "ccaei" "ccaeo" [6] "ccaep" "ccaes" "ccaet" "redbook" "state" [11] "wgt" "ccaea_st_wt" "ccaet_st_wt" "ccaes_monthly" "ccaes_annual" [16] "ccaeo_monthly" "ccaeo_annual" "ccaed_monthly" "ccaed_annual" "ccaes_admmon_xwalk" [21] "ccaes_monthly_wxw" "ccaed_svcmon_xwalk" "ccaed_monthly_wxw" "ccaeo_svcmon_xwalk" "ccaeo_monthly_wxw" [26] "acons_pre" "mcons_pre" "ccs" "acons_diag" "mcons_diag" [31] "readm" "acons_readm" "mcons_readm" "mcons" "acons" > > > # create a temporary person-year table > dbSendQuery( + db , + 'CREATE TABLE temp AS + SELECT + datatyp , + yr , + enrolid , + SUM( wgt ) AS sum_wgt , + SUM( CAST( ( rx_pay ) > 250 AS INTEGER ) ) AS rx_pay_above_250 , + SUM( CAST( ( rx_copay + rx_coins + rx_deduct ) > 250 AS INTEGER ) ) AS rx_copay_coins_deduct_above_250 + FROM + mcons + WHERE + datatyp = 1 + GROUP BY + datatyp , yr , enrolid + ORDER BY + datatyp , yr , enrolid + WITH DATA' + ) Error in readBin(con, "integer", n = 1, size = 2, signed = FALSE, endian = "little") : error reading from the connection > # # # # mserver is dead

2 2

Monetdb clusters VS Distributed Query Processing
by imad hajj chahine 22 Sep '15

22 Sep '15

Hi, I am trying to understand the main difference between clusters and the remote table introduced in JUL2015 . Correct me if I am wrong, in clusters the complete table is copied over all nodes, and monetdb will do the query parallel execution on the nodes and result concat. In the remote table I have more control on executing the query on a part of a table on a selected node depending on resources availables. If this is true, are the following point valid: 1. its better to have identical nodes for clusters 2. the execution time is inversely proportional to the number of nodes in the clusters 3. the executing time is dictated by the slowest node in cluster 4. fail-over is by default supported in cluster configuration One last question about the supported queries in these 2 modes(groupby, order, limit). if any, a reference to a documentation about the clustering is appreciated. Thank you.

2 1

Two questions about R integration
by Roberto Cornacchia 22 Sep '15

22 Sep '15

Hi, I have 2 questions about R integration. 1) I see that missing packages are automatically installed when invoked by library() calls. That is really cool. The question: if I need a library in a function, will this actually be loaded at every function call? 2) How is a SQL type date translated to R? Apparently not "Date", because I tried to use it as such in the declared procedure and I got a complaint. I tried to figure the type myself with this: sql> create function dt(d date) returns string language R { class(d) }; sql> select dt( cast('2015-09-21' as date) ); but unfortunately this triggered a server assertion :/ mserver5: .../src/monetdb5/mal/mal_interpreter.c:648: runMALsequence: Assertion `t == stk->stk[a].vtype' failed. Thanks, Roberto

2 2

sys.analyze not working
by Robert Koch 19 Sep '15

19 Sep '15

Following the manual https://www.monetdb.org/Documentation/Cookbooks/SQLrecipes/statistics I am trying to reproduce this, but it fails with a type conversion error: sql>call sys.analyze('sys', 'types'); conversion of string 'sys' to type int failed. sql>SELECT * FROM sys.statistics; +-----------+------+-------+-------+--------+-------+--------+------+--------+--------+ | column_id | type | width | stamp | sample | count | unique | nils | minval | maxval |> +===========+======+=======+=======+========+=======+========+======+========+========+ +-----------+------+-------+-------+--------+-------+--------+------+--------+--------+ 0 tuples (3.013ms) !1 column dropped! Tried it with different schema/table/column names. Both with system and user-generated tables. Always the same error. Running 11.21.5 here. Thanks.

3 2