- developers-list - monetdb.org

Parameters in bind function
by Narendra Pradeep 08 Aug '16

08 Aug '16

Hello everyone , I am trying to understand the MAL statements for joining three tables . On which I came across bind function in MAL statement . I have a table lineitem with l_quantity in it . So what does the following statements means 1 ) ( X_94:bat[:oid,:oid] ,X_95:bat[:oid,:int] ) := sql.bind(X_4,"sys","lineitem","l_quantity",2,0,4); 2 ) (X_96:bat[:oid,:oid] ,X_97:bat[:oid,:int] ) := sql.bind(X_4,"sys","lineitem","l_quantity",2,1,4); what does the 5 th and 6 th argument means ? Regards , Pradeep

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jdbc exception
by Panagiotis Koutsourakis 05 Aug '16

05 Aug '16

Hello, has anyone encountered something like the following exception before? java.lang.AssertionError: Server sent a block larger than BLOCKsize: 13456 > 8193 at nl.cwi.monetdb.mcl.net.MapiSocket$BlockInputStream.readBlock(MapiSocket.java:917) at nl.cwi.monetdb.mcl.net.MapiSocket$BlockInputStream.read(MapiSocket.java:966) 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) at java.io.InputStreamReader.read(InputStreamReader.java:184) at java.io.BufferedReader.fill(BufferedReader.java:161) at java.io.BufferedReader.readLine(BufferedReader.java:324) at java.io.BufferedReader.readLine(BufferedReader.java:389) at nl.cwi.monetdb.mcl.io.BufferedMCLReader.readLine(BufferedMCLReader.java:119) at nl.cwi.monetdb.mcl.net.MapiSocket.connect(MapiSocket.java:278) at nl.cwi.monetdb.mcl.net.MapiSocket.connect(MapiSocket.java:398) at nl.cwi.monetdb.mcl.net.MapiSocket.connect(MapiSocket.java:252) at nl.cwi.monetdb.jdbc.MonetConnection.<init>(MonetConnection.java:232) at nl.cwi.monetdb.jdbc.MonetDriver.connect(MonetDriver.java:171) at java.sql.DriverManager.getConnection(DriverManager.java:664) at java.sql.DriverManager.getConnection(DriverManager.java:247) Does anyone has any tips? The jdbc driver version used is 2.13.

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Re: MonetDB: default - We were severely underquoting according to th...
by Niels Nes 01 Aug '16

01 Aug '16

Sjoerd Kunnen we wel voor perl-DBI testen? Nu draaien somige tests niet (geven errors) omdat perl-DBI mist. Niels On Mon, Aug 01, 2016 at 03:55:06PM +0200, Sjoerd Mullender wrote: > Changeset: a64440dcd8bf for MonetDB > URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=a64440dcd8bf > Modified Files: > configure.ag > Branch: default > Log Message: > > We were severely underquoting according to the autoconf documentation. > > > diffs (truncated from 2554 to 300 lines): > > diff --git a/configure.ag b/configure.ag > --- a/configure.ag > +++ b/configure.ag > @@ -9,7 +9,7 @@ dnl Copyright 1997 - July 2008 CWI, Augu > > # Process this file with autoconf to produce a configure script. > > -AC_PREREQ(2.60) > +AC_PREREQ([2.60]) > AC_INIT([MonetDB], [11.24.0], [info(a)monetdb.org] [MonetDB], [http://www.monetdb.org/] > AC_CONFIG_AUX_DIR([buildtools/conf]) > AC_CONFIG_MACRO_DIR([buildtools/conf]) > @@ -22,13 +22,13 @@ AC_CONFIG_HEADERS([monetdb_config.h]) > AC_SUBST([CONFIG_H], [monetdb_config.h]) > > HOST=[$target] > -AC_DEFINE_UNQUOTED(HOST, "$HOST", [Host identifier]) > +AC_DEFINE_UNQUOTED([HOST], ["$HOST"], [Host identifier]) > > if test x"$target_os" = xcygwin; then > - AC_DEFINE(WIN32, 1, [Define on Microsoft Windows (also under Cygwin)]) > + AC_DEFINE([WIN32], 1, [Define on Microsoft Windows (also under Cygwin)]) > fi > -AM_CONDITIONAL(NOT_WIN32, test x"$target_os" != xcygwin) > -AM_CONDITIONAL(NATIVE_WIN32, false) > +AM_CONDITIONAL([NOT_WIN32], [test x"$target_os" != xcygwin]) > +AM_CONDITIONAL([NATIVE_WIN32], [false]) > > m4_ifndef([PKG_PROG_PKG_CONFIG], > [m4_fatal([Could not locate the pkg-config autoconf > @@ -57,16 +57,16 @@ AC_DEFUN([MONETDB_VERSION_TO_NUMBER], > # except set the variables. The command to set them in case we do > # need to escape the \'s is Qvar=`echo "$var" | sed 's/\\\\/\\\\\\\\/g'` > BUILD=[`pwd`] > -AC_SUBST(BUILD) > +AC_SUBST([BUILD]) > > SOURCE=[`(cd $srcdir && pwd)`] > -AC_SUBST(SOURCE) > +AC_SUBST([SOURCE]) > > . $srcdir/libversions > -AC_SUBST(GDK_VERSION) > -AC_SUBST(MAPI_VERSION) > -AC_SUBST(MONETDB5_VERSION) > -AC_SUBST(STREAM_VERSION) > +AC_SUBST([GDK_VERSION]) > +AC_SUBST([MAPI_VERSION]) > +AC_SUBST([MONETDB5_VERSION]) > +AC_SUBST([STREAM_VERSION]) > > # if no --prefix option, we must set Qprefix to the default value > # the problem is that prefix is set very late in the process if it > @@ -77,14 +77,14 @@ else > Qprefix="${prefix}" > fi > Qprefix="`echo "$Qprefix" | sed 's/\\\\/\\\\\\\\/g'`" > -AC_SUBST(Qprefix) > +AC_SUBST([Qprefix]) > # exec_prefix is created very late, so let make do the expansion > if test "${exec_prefix}x" = "NONEx"; then > Qexec_prefix='${prefix}' > else > Qexec_prefix="`echo "$exec_prefix" | sed 's/\\\\/\\\\\\\\/g'`" > fi > -AC_SUBST(Qexec_prefix) > +AC_SUBST([Qexec_prefix]) > > if test -f "$srcdir"/vertoo.data; then > dnl Developers compiling from Mercurial: > @@ -124,21 +124,21 @@ case "$CC" in > ;; > esac > > -AC_DEFINE(MONETDB_RELEASE, "unreleased", [Release name or "unreleased"]) > +AC_DEFINE([MONETDB_RELEASE], ["unreleased"], [Release name or "unreleased"]) > > dft_gdk=yes > -AC_ARG_ENABLE(gdk, > - AS_HELP_STRING([--enable-gdk], > - [enable support for GDK (default=yes)]), > - enable_gdk=$enableval, > - enable_gdk=$dft_gdk) > +AC_ARG_ENABLE([gdk], > + [AS_HELP_STRING([--enable-gdk], > + [enable support for GDK (default=yes)])], > + [enable_gdk=$enableval], > + [enable_gdk=$dft_gdk]) > > dft_monetdb5=yes > -AC_ARG_ENABLE(monetdb5, > - AS_HELP_STRING([--enable-monetdb5], > - [enable support for MonetDB5 (default=yes)]), > - enable_monetdb5=$enableval, > - enable_monetdb5=$dft_monetdb5) > +AC_ARG_ENABLE([monetdb5], > + [AS_HELP_STRING([--enable-monetdb5], > + [enable support for MonetDB5 (default=yes)])], > + [enable_monetdb5=$enableval], > + [enable_monetdb5=$dft_monetdb5]) > case "$enable_gdk-$enable_monetdb5" in > no-yes) > AC_MSG_ERROR([MonetDB5 requires GDK.]) > @@ -150,32 +150,32 @@ no-auto) > esac > > dft_fits=auto > -AC_ARG_ENABLE(fits, > - AS_HELP_STRING([--enable-fits], > - [enable support for FITS (default=auto)]), > - enable_fits=$enableval, > - enable_fits=$dft_fits) > +AC_ARG_ENABLE([fits], > + [AS_HELP_STRING([--enable-fits], > + [enable support for FITS (default=auto)])], > + [enable_fits=$enableval], > + [enable_fits=$dft_fits]) > > dft_netcdf=auto > -AC_ARG_ENABLE(netcdf, > - AS_HELP_STRING([--enable-netcdf], > - [enable support for netcdf (default=auto)]), > - enable_netcdf=$enableval, > - enable_netcdf=$dft_netcdf) > +AC_ARG_ENABLE([netcdf], > + [AS_HELP_STRING([--enable-netcdf], > + [enable support for netcdf (default=auto)])], > + [enable_netcdf=$enableval], > + [enable_netcdf=$dft_netcdf]) > > dft_lidar=auto > -AC_ARG_ENABLE(lidar, > - AS_HELP_STRING([--enable-lidar], > - [enable support for LiDAR data (default=auto)]), > - have_lidar=$enableval, > - have_lidar=$dft_lidar) > +AC_ARG_ENABLE([lidar], > + [AS_HELP_STRING([--enable-lidar], > + [enable support for LiDAR data (default=auto)])], > + [have_lidar=$enableval], > + [have_lidar=$dft_lidar]) > > dft_sql=yes > -AC_ARG_ENABLE(sql, > - AS_HELP_STRING([--enable-sql], > - [enable support for MonetDB/SQL (default=yes)]), > - enable_sql=$enableval, > - enable_sql=$dft_sql) > +AC_ARG_ENABLE([sql], > + [AS_HELP_STRING([--enable-sql], > + [enable support for MonetDB/SQL (default=yes)])], > + [enable_sql=$enableval], > + [enable_sql=$dft_sql]) > case "$enable_monetdb5-$enable_sql" in > no-yes) > AC_MSG_ERROR([MonetDB/SQL requires MonetDB5.]) > @@ -187,11 +187,11 @@ no-auto) > esac > > dft_geom=auto > -AC_ARG_ENABLE(geom, > - AS_HELP_STRING([--enable-geom], > - [enable support for geom module (default=auto)]), > - enable_geom=$enableval, > - enable_geom=$dft_geom) > +AC_ARG_ENABLE([geom], > + [AS_HELP_STRING([--enable-geom], > + [enable support for geom module (default=auto)])], > + [enable_geom=$enableval], > + [enable_geom=$dft_geom]) > case "$enable_monetdb5-$enable_geom" in > no-yes) > AC_MSG_ERROR([geom module requires MonetDB5]) > @@ -203,11 +203,11 @@ no-auto) > esac > > dft_shp=auto > -AC_ARG_ENABLE(shp, > - AS_HELP_STRING([--enable-shp], > - [enable support for ESRI Shapefiles (default=auto)]), > - have_shp=$enableval, > - have_shp=$dft_shp) > +AC_ARG_ENABLE([shp], > + [AS_HELP_STRING([--enable-shp], > + [enable support for ESRI Shapefiles (default=auto)])], > + [have_shp=$enableval], > + [have_shp=$dft_shp]) > case "$enable_geom-$have_shp" in > no-yes) > AC_MSG_ERROR([ESRI Shapefile vault requires the geom module]) > @@ -219,85 +219,85 @@ no-auto) > esac > > dft_mapi=yes > -AC_ARG_ENABLE(mapi, > - AS_HELP_STRING([--enable-mapi], > - [Enable MAPI (default=yes)]), > - enable_mapi=$enableval, > - enable_mapi=$dft_mapi) > -AM_CONDITIONAL(HAVE_MAPI, test x$enable_mapi != xno) > +AC_ARG_ENABLE([mapi], > + [AS_HELP_STRING([--enable-mapi], > + [Enable MAPI (default=yes)])], > + [enable_mapi=$enableval], > + [enable_mapi=$dft_mapi]) > +AM_CONDITIONAL([HAVE_MAPI], [test x$enable_mapi != xno]) > if test "x$enable_mapi" != xno; then > - AC_DEFINE(HAVE_MAPI, 1, [Enable MAPI]) > + AC_DEFINE([HAVE_MAPI], 1, [Enable MAPI]) > fi > > dft_embedded=no > -AC_ARG_ENABLE(embedded, > - AS_HELP_STRING([--enable-embedded], > - [enable support for running MonetDB as a library (default=no)]), > - enable_embedded=$enableval, > - enable_embedded=$dft_embedded) > -AM_CONDITIONAL(HAVE_EMBEDDED, test x$enable_embedded != xno) > +AC_ARG_ENABLE([embedded], > + [AS_HELP_STRING([--enable-embedded], > + [enable support for running MonetDB as a library (default=no)])], > + [enable_embedded=$enableval], > + [enable_embedded=$dft_embedded]) > +AM_CONDITIONAL([HAVE_EMBEDDED], [test x$enable_embedded != xno]) > if test "x$enable_embedded" != xno; then > - AC_DEFINE(HAVE_EMBEDDED, 1, [Support for MonetDB as a library]) > + AC_DEFINE([HAVE_EMBEDDED], 1, [Support for MonetDB as a library]) > fi > > dft_embedded_r=no > -AC_ARG_ENABLE(embedded-r, > - AS_HELP_STRING([--enable-embedded-r], > - [enable support for running MonetDB as a library for R (default=no)]), > - enable_embedded_r=$enableval, > - enable_embedded_r=$dft_embedded_r) > -AM_CONDITIONAL(HAVE_EMBEDDED_R, test x$enable_embedded_r != xno) > +AC_ARG_ENABLE([embedded-r], > + [AS_HELP_STRING([--enable-embedded-r], > + [enable support for running MonetDB as a library for R (default=no)])], > + [enable_embedded_r=$enableval], > + [enable_embedded_r=$dft_embedded_r]) > +AM_CONDITIONAL([HAVE_EMBEDDED_R], [test x$enable_embedded_r != xno]) > if test "x$enable_embedded_r" != xno; then > - AC_DEFINE(HAVE_EMBEDDED_R, 1, [Support for MonetDB as a library for R]) > + AC_DEFINE([HAVE_EMBEDDED_R], 1, [Support for MonetDB as a library for R]) > fi > > dft_gsl=auto > -AC_ARG_ENABLE(gsl, > - AS_HELP_STRING([--enable-gsl], > - [enable support for GSL (default=auto)]), > - enable_gsl=$enableval, > - enable_gsl=$dft_gsl) > +AC_ARG_ENABLE([gsl], > + [AS_HELP_STRING([--enable-gsl], > + [enable support for GSL (default=auto)])], > + [enable_gsl=$enableval], > + [enable_gsl=$dft_gsl]) > > dft_rintegration=auto > -AC_ARG_ENABLE(rintegration, > - AS_HELP_STRING([--enable-rintegration], > - [enable support for R integration into MonetDB (default=auto)]), > - enable_rintegration=$enableval, > - enable_rintegration=$dft_rintegration) > +AC_ARG_ENABLE([rintegration], > + [AS_HELP_STRING([--enable-rintegration], > + [enable support for R integration into MonetDB (default=auto)])], > + [enable_rintegration=$enableval], > + [enable_rintegration=$dft_rintegration]) > > dft_pyintegration=auto > -AC_ARG_ENABLE(pyintegration, > - AS_HELP_STRING([--enable-pyintegration], > - [enable support for Python integration into MonetDB (default=auto)]), > - enable_pyintegration=$enableval, > - enable_pyintegration=$dft_pyintegration) > +AC_ARG_ENABLE([pyintegration], > + [AS_HELP_STRING([--enable-pyintegration], > + [enable support for Python integration into MonetDB (default=auto)])], > + [enable_pyintegration=$enableval], > + [enable_pyintegration=$dft_pyintegration]) > > dft_odbc=auto > -AC_ARG_ENABLE(odbc, > - AS_HELP_STRING([--enable-odbc], > - [compile the MonetDB ODBC driver (default=auto)]), > - enable_odbc=$enableval, > - enable_odbc=$dft_odbc) > +AC_ARG_ENABLE([odbc], > + [AS_HELP_STRING([--enable-odbc], > + [compile the MonetDB ODBC driver (default=auto)])], > + [enable_odbc=$enableval], > + [enable_odbc=$dft_odbc]) > > dft_testing=auto > -AC_ARG_ENABLE(testing, > - AS_HELP_STRING([--enable-testing], > - [enable support for testing (default=auto)]), > - enable_testing=$enableval, > _______________________________________________ > checkin-list mailing list > checkin-list(a)monetdb.org > https://www.monetdb.org/mailman/listinfo/checkin-list -- Niels Nes, Manager ITF, Centrum Wiskunde & Informatica (CWI) Science Park 123, 1098 XG Amsterdam, The Netherlands room L3.14, phone ++31 20 592-4098 sip:4098@sip.cwi.nl url: https://www.cwi.nl/people/niels e-mail: Niels.Nes(a)cwi.nl

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Parameters in bind function
by Narendra Pradeep 01 Aug '16

01 Aug '16

Hello everyone , I am trying to understand the MAL statements for joining three tables . On which I came across bind function in MAL statement . I have a table lineitem with l_quantity in it . So what does the following statements means 1 ) ( X_94:bat[:oid,:oid] ,X_95:bat[:oid,:int] ) := sql.bind(X_4,"sys","lineitem","l_quantity",2,0,4); 2 ) (X_96:bat[:oid,:oid] ,X_97:bat[:oid,:int] ) := sql.bind(X_4,"sys","lineitem","l_quantity",2,1,4); what does the 5 th and 6 th argument means ?

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does cracking implemented in monetdb
by Narendra Pradeep 28 Jul '16

28 Jul '16

My questions are 1) Does cracking implemented in monetdb ? 2) Which file contains the code for cracking in source ? 3) Can we trace cracking and find whether query reads record from disc or the cracked columns ? Thanks in advance. regards , Pradeep.

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Re: MonetDB: Jun2016 - Trace BATs should be reset before the next TR...
by Sjoerd Mullender 28 Jul '16

28 Jul '16

This is not correct. I made the exact opposite change in changeset 080dcfcb43e4 in order to fix memory leaks. That worked, but now those leaks are back. Clearly another solution is needed. On 28/07/16 00:31, Martin Kersten wrote: > Changeset: 25c896ae6a53 for MonetDB > URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=25c896ae6a53 > Modified Files: > monetdb5/mal/mal_profiler.c > Branch: Jun2016 > Log Message: > > Trace BATs should be reset before the next TRACE call > BBPunfix was slipped in, while it should simply be a BATclear. > > > diffs (36 lines): > > diff --git a/monetdb5/mal/mal_profiler.c b/monetdb5/mal/mal_profiler.c > --- a/monetdb5/mal/mal_profiler.c > +++ b/monetdb5/mal/mal_profiler.c > @@ -761,19 +761,19 @@ clearTrace(void) > return; /* not initialized */ > } > /* drop all trace tables */ > - BBPunfix(TRACE_id_event->batCacheid); > - BBPunfix(TRACE_id_time->batCacheid); > - BBPunfix(TRACE_id_pc->batCacheid); > - BBPunfix(TRACE_id_thread->batCacheid); > - BBPunfix(TRACE_id_ticks->batCacheid); > - BBPunfix(TRACE_id_rssMB->batCacheid); > - BBPunfix(TRACE_id_tmpspace->batCacheid); > - BBPunfix(TRACE_id_inblock->batCacheid); > - BBPunfix(TRACE_id_oublock->batCacheid); > - BBPunfix(TRACE_id_minflt->batCacheid); > - BBPunfix(TRACE_id_majflt->batCacheid); > - BBPunfix(TRACE_id_nvcsw->batCacheid); > - BBPunfix(TRACE_id_stmt->batCacheid); > + BBPclear(TRACE_id_event->batCacheid); > + BBPclear(TRACE_id_time->batCacheid); > + BBPclear(TRACE_id_pc->batCacheid); > + BBPclear(TRACE_id_thread->batCacheid); > + BBPclear(TRACE_id_ticks->batCacheid); > + BBPclear(TRACE_id_rssMB->batCacheid); > + BBPclear(TRACE_id_tmpspace->batCacheid); > + BBPclear(TRACE_id_inblock->batCacheid); > + BBPclear(TRACE_id_oublock->batCacheid); > + BBPclear(TRACE_id_minflt->batCacheid); > + BBPclear(TRACE_id_majflt->batCacheid); > + BBPclear(TRACE_id_nvcsw->batCacheid); > + BBPclear(TRACE_id_stmt->batCacheid); > TRACE_init = 0; > MT_lock_unset(&mal_contextLock); > initTrace(); > _______________________________________________ > checkin-list mailing list > checkin-list(a)monetdb.org > https://www.monetdb.org/mailman/listinfo/checkin-list > -- Sjoerd Mullender

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Instrumentation in monetdb
by Narendra Pradeep 22 Jul '16

22 Jul '16

eello everyone , How can I get instumemtation in monetdb ? I need thedetails like planning time , execution time for each MAL statement in monetdb . Is there any command for it ? regards , Pradeep

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Fwd: Monet php_mapi.inc
by Mark Raasveldt 22 Jul '16

22 Jul '16

> Begin forwarded message: > > From: Alberto Ferrari <aferrari(a)starconnecting.com> > Subject: Monet php_mapi.inc > Date: 21 July 2016 at 17:22:34 GMT+2 > To: Mark Raasveldt <m.raasveldt(a)cwi.nl> > > Hi Mark, > (about https://dev.monetdb.org/hg/MonetDB/file/tip/clients/php/lib/php_mapi.inc) > > I've been using the "php_mapi.inc" in my php web application in the > last few months. So I modified the "php_mapi.inc" to a php class, > which is more efficient and correct (to me). > I am not registered in the Mercurial repo, so , if you (or somebody) > are interested on my "class" version, I can send you attached, and > then feel free to publish it, if you want. > Just tell me. > > regards > Alberto Ferrari.

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Announcement: New Jun2016-SP1 Bugfix release of MonetDB suite
by Sjoerd Mullender 22 Jul '16

22 Jul '16

The MonetDB team at CWI/MonetDB BV is pleased to announce the Jun2016-SP1 bugfix release of the MonetDB suite of programs. More information about MonetDB can be found on our website at <http://www.monetdb.org/>. For details on this release, please see the release notes at <http://www.monetdb.org/Downloads/ReleaseNotes>. As usual, the download location is <http://dev.monetdb.org/downloads/>. Jun 2016-SP1 bugfix release . * Lots of memory leaks have been plugged across the whole system. Java Module * Corrected PROCEDURE_TYPE output value of method DatabaseMetaData.getProcedures(). It used to return procedureReturnsResult. Now it returns procedureNoResult. Corrected ORDINAL_POSITION output value of method DatabaseMetaData.getProcedureColumns(). It used to start with 0, but as procedures do not return a result value it now starts with 1 for all the procedure arguments, as defined by the JDBC API. * Improved output of method DatabaseMetaData.getProcedures(). The REMARKS column now contains the procedure definition as stored in sys.functions.func. The SPECIFIC_NAME column now contains the procedure unique identifier as stored in sys.functions.id. This allows the caller to retrieve the specific overloaded procedure which has the same name, but different arguments. Also improved output of method DatabaseMetaData.getProcedureColumns(). The SPECIFIC_NAME column now contains the procedure unique identifier as stored in sys.functions.id. This allows the caller to retrieve the proper arguments of the specific overloaded procedure by matching the SPECIFIC_NAME value. * Improved output of method DatabaseMetaData.getFunctions(). The REMARKS column now contains the function definition as stored in sys.functions.func. The SPECIFIC_NAME column now contains the function unique identifier as stored in sys.functions.id. This allows the caller to retrieve the specific overloaded function which has the same name, but different arguments. Also improved output of method DatabaseMetaData.getFunctionColumns(). The SPECIFIC_NAME column now contains the function unique identifier as stored in sys.functions.id. This allows the caller to retrieve the proper arguments of the specific overloaded function by matching the SPECIFIC_NAME value. Bug Fixes * 4014: KILL signal * 4021: Analyze query does not escape input [security] * 4026: JDBC driver incorrectly converts TINYINT fields to String instead of an integer type. * 4028: inputs not the same size * 4031: mclient doesn't accept - argument to refer to stdin * 4032: no decimal places after update. ODBC driver * 4035: SQL Function call bug * 4036: Possible sql_catalog corruption due to unclean backuped tail

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Tracking query & user information during execution
by Playfair, Daniel 19 Jul '16

19 Jul '16

Hi MonetDB Developers, I'm working to add intra-query checkpoint/restart functionality to MonetDB as part of my PhD work. I have a partial implementation and have completed the component for transmitting intermediate values (to a separate middleware), and have a plan that I think should work for replay. Most of these modifications are in the runMALsequence function in the mal interpreter. Currently my implementation transmits all intermediates and I'm having some difficulty on the component to selectively transmit selected intermediates. I was hoping you might be able answer some of my questions to point me in the right direction on this aspect. I intend for the actual checkpoint planning to be performed on the query plan graphs in an offline step. This relates to one of my problems - The MAL variable names for intermediates seem to change accross executions. 1. Is there a way to have these identifiers be consistent? 2. What factors determine the values they take? Secondly, I am having difficulty with tracking/accessing information about the user, original SQL query, and current MAL operation step to be able to tag the transmitted intermediates with sufficient data for the middleware & load balancer to be able to relate this to a user session & query. I believe this should be accessible via 3. How can I access this information from the inputs available in runMALsequence (in mal_interpreter.c) I believe it's probably somewhere in the mal stack, instruction record, or client structs, but I am having difficulty here. Any help and input would be greatly appreciated. Many thanks, ~ Daniel.

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