- users-list - monetdb.org

M5server.bat error
by Amit Ambekar 22 Mar '18

22 Mar '18

Hi, i had installed monetdb on Microsoft server 12, but now when i want to start M5server , error occured. And i had tried this on various machine of Windows Server 2012, still same issue occurred. Is monetdb is not compatible with Windows 2012 server?

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How to use MonetDB cluster?
by Li Japin 20 Mar '18

20 Mar '18

Hi, Recently, I read the MonetDB cluster management document, but I'm not sure which situation will use the MonetDB cluster and how to use it. I guess the cluster will combine with REMOTE table, is that right? But how can I monitor the remote table is online? using `monetdb discover` command? Best regards, Japin

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merge tables: how to reveal member tabels?
by Stefan Manegold 15 Mar '18

15 Mar '18

Hi, given a merge table, e.g., sql>create table t1(a int, b real); operation successful (9.315ms) sql>create table t2(a int, b real); operation successful (8.497ms) sql>create merge table mt(a int, b real); operation successful (8.218ms) sql>alter table mt add table t1; operation successful (7.174ms) sql>alter table mt add table t2; operation successful (6.178ms) How can I see which tables are members of a merge tables, i.e., in this case, how can I see that t1 & t2 are members of mt? a plain select (obviously) only shows the content of mt, i.e., the combined content of t1 & t2 ... sql>select * from mt; +---+---+ | a | b | +===+===+ +---+---+ 0 tuples (4.690ms) Is there a query to get this directly from mt, or where can I otherwise find that info in the SQL catalog? Thanks! Stefan -- | Stefan.Manegold(a)CWI.nl | DB Architectures (DA) | | www.CWI.nl/~manegold/ | Science Park 123 (L321) | | +31 (0)20 592-4212 | 1098 XG Amsterdam (NL) |

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Can I avoid "n affected rows" messages?
by Eyal Rozenberg 15 Mar '18

15 Mar '18

When you perform an insert or update using mclient, you get a line printed saying "n rows affected". Now, I can avoid this line if I use -f trash on the command line - but I don't want to give up on actual output. I can also pass the output through a grep -Ev "^[0-9]+ rows affected$" as a filter, but I was wondering if I could just turn that message off somehow. I couldn't find a command-line switch which would have this effect. Eyal

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GDK reported error. MT_mremap: mremap failed. !OS: Cannot allocate memory
by RanchoYuan 15 Mar '18

15 Mar '18

Hello all, I did a tpc-ds testing on MonetDB, and when it ran some queries, the error message was appeared: GDK reported error. MT_mremap: mremap(0x7ffdc0000000,2054553600,2465464320) failed !OS: Cannot allocate memory HEAPextend: failed to extend to 2465464320 for 44/4415.tail: GDKmremap() failed It seems that the memory has been ran out. But I have no idea what is the cause of this error. The version of Monetdb is 11.27.13, and OS is Ubunbtu-16.04 with memory is 8G, and with 20G testing data.(It is worth mentioning, a table named store_sales is 7.5G in the query.) The query statement is: with frequent_ss_items as ( select substr(i_item_desc,1,30) itemdesc ,i_item_sk item_sk ,d_date solddate ,count(*) cnt from store_sales ,date_dim ,item where ss_sold_date_sk = d_date_sk and ss_item_sk = i_item_sk and d_year in (1999,1999+1,1999+2,1999+3) group by itemdesc ,i_item_sk ,d_date having count(*) >4 ), max_store_sales as ( select max(csales) tpcds_cmax from ( select c_customer_sk ,sum(ss_quantity*ss_sales_price) csales from store_sales ,customer ,date_dim where ss_customer_sk = c_customer_sk and ss_sold_date_sk = d_date_sk and d_year in (1999,1999+1,1999+2,1999+3) group by c_customer_sk ) x ), best_ss_customer as ( select c_customer_sk ,sum(ss_quantity*ss_sales_price) ssales from store_sales ,customer where ss_customer_sk = c_customer_sk group by c_customer_sk having sum(ss_quantity*ss_sales_price) > (95/100.0) * ( select * from max_store_sales ) ) select sum(sales) from ( select cs_quantity*cs_list_price sales from catalog_sales ,date_dim where d_year = 1999 and d_moy = 1 and ws_sold_date_sk = d_date_sk and ws_item_sk in (select item_sk from frequent_ss_items) and ws_bill_customer_sk in (select c_customer_sk from best_ss_customer)) y limit 100; Please give me some advice if you have any idea, either of the direct question or my expression. Thanks a lot! Regards, Rancho

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MonetDB - table without column- NOT able to delete it or use it
by Sharma, Sreejith 12 Mar '18

12 Mar '18

All, We are finding a strange issue where below table has been created via a shell script. Strangely it doesn't show up any columns and when we try to drop it's saying table doesn't exists. Is there any way below can happen? Is this because it's corrupted? How can we remove this? CREATE TABLE "DM_MON_TSV_STG_T1"."AMA_US_IRI_8135_2001" ( ); Regards, Sreejith

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Backup and restore in Monetdb
by Amit Ambekar 10 Mar '18

10 Mar '18

Hi, How i can take back of monetdb database , and how to restore it?

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current_time() precision
by Roberto Cornacchia 28 Feb '18

28 Feb '18

sql>select current_time(); +-----------------------+ | L2 | +=======================+ | 17:05:10.000000+01:00 | +-----------------------+ 1 tuple (0.796ms) Is it expected that the result type's precision of current_time() is limited to seconds? Any way to get milliseconds?

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Monetdb hanging on query
by Manuel Pagliai 27 Feb '18

27 Feb '18

Hello, I am using Monetdb as the query engine of an application currently in development. I am connecting to monetdb via a jdbc connection. I can easily reproduce a scenario where monetdb gets stuck on a query, and never complete execution. Although reproducible, the issue is non deterministic, and it can occur while executing different queries, or not occur at all. When it happens I can see the thread stuck at I extracted the queries submitted to monetdb, and execute them via a standalone client (both the native client and a jdbc-based one) rather than our application, but I have been unable to reproduce the issue that way. I guess timing is important. The problem still occur even when queries are submitted sequentially and setting gdk_nr_threads=1 and sql_optimizer=sequential_pipe. The issue happens in Jul 2017-SP3 bugfix release (11.27.11), running on a Windows 7 machine. I have not tried 11.27.13, but by looking at the bug fixes I can't see anything relevant to this issue. Is there something that I can try, or a way to gather more information about what is happening ? I can share both the data, and the complete list of queries used during this scenario. Thanks, Best regards, *Manuel Pagliai* Visokio Ltd www.visokio.com +44 20 7351 4646 P.S. This is the stack-trace of the thread submitting the query when this happens: at java.net.SocketInputStream.socketRead0(Native Method) at java.net.SocketInputStream.socketRead(SocketInputStream.java:116) at java.net.SocketInputStream.read(SocketInputStream.java:171) at java.net.SocketInputStream.read(SocketInputStream.java:141) at java.io.BufferedInputStream.fill(BufferedInputStream.java:246) at java.io.BufferedInputStream.read1(BufferedInputStream.java:286) at java.io.BufferedInputStream.read(BufferedInputStream.java:345) - locked <0x00000000cae0b730> (a java.io.BufferedInputStream) at nl.cwi.monetdb.mcl.net.MapiSocket$BlockInputStream._read(Unknown Source) at nl.cwi.monetdb.mcl.net.MapiSocket$BlockInputStream.readBlock(Unknown Source) at nl.cwi.monetdb.mcl.net.MapiSocket$BlockInputStream.read(Unknown Source) at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284) at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326) at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178) - locked <0x00000000cae13810> (a java.io.InputStreamReader) at java.io.InputStreamReader.read(InputStreamReader.java:184) at java.io.BufferedReader.fill(BufferedReader.java:161) at java.io.BufferedReader.readLine(BufferedReader.java:324) - locked <0x00000000cae13810> (a java.io.InputStreamReader) at java.io.BufferedReader.readLine(BufferedReader.java:389) at nl.cwi.monetdb.mcl.io.BufferedMCLReader.readLine(Unknown Source) at nl.cwi.monetdb.mcl.io.BufferedMCLReader.waitForPrompt(Unknown Source) - locked <0x00000000cae137d8> (a nl.cwi.monetdb.mcl.io.BufferedMCLReader) at nl.cwi.monetdb.jdbc.MonetConnection$ResponseList.executeQuery(Unknown Source) - locked <0x00000000cae0b430> (a nl.cwi.monetdb.mcl.net.MapiSocket) at nl.cwi.monetdb.jdbc.MonetConnection$ResponseList.processQuery(Unknown Source) at nl.cwi.monetdb.jdbc.MonetStatement.internalExecute(Unknown Source) at nl.cwi.monetdb.jdbc.MonetStatement.execute(Unknown Source) at nl.cwi.monetdb.jdbc.MonetStatement.executeQuery(Unknown Source)

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MonetDB :: Alter statement to change datatype
by Sharma, Sreejith 22 Feb '18

22 Feb '18

All, Is it possible to change the datatype of a column in an existing table? With or without data? I saw the only way to change is to create a temporary column and swap if data is present. Is it true? Regards, Sreejith

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