Indexes created by dbt3 (TPC-H)
February 7th, 2012
DBT3 creates many indexes: one primary index on the primary key of each table, and the following secondary indexes:
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Archive
Archive for the ‘Coding’ Category
Error in rf2 of DBT3 (TPC-H)
February 3rd, 2012
First of all, I am using PostgreSQL. The error message looks like this:
ERROR: missing FROM-clause entry for table "tmp_orderkey1" LINE 1: delete from lineitem where l_orderkey=tmp_orderkey1.orderkey... ERROR: missing FROM-clause entry for table "tmp_orderkey1" LINE 1: delete from orders where o_orderkey=tmp_orderkey1.orderkey...
A bug in DBT3 (TPC-H)
February 2nd, 2012
First of all, this bug may not occur in every environment. I suspect that it has something to do the implementation of C library on your machine, specifically, the implementation of function “strcpy”.
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Write a kernel module that its parameters can be dynamically changed
February 2nd, 2012
We know that every Linux kernel module can accept parameters from command line when it is first loaded, but sometimes we want to change the behavior of a module on the fly, without requiring the module to be removed and inserted again. To achieve this flexibility, we take advantage of the sysfs.
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Location of the kernel symbol table on Fedora Linux
February 2nd, 2012
check out /proc/kallsyms. You don’t have to be a root to read its content. The normal place “/proc/ksyms” does not exist on my Fedora.
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Adjust Vim split window size
January 18th, 2012
1. Change the height (number of rows) of a split window
To increase by 10, type command
:res+10
Error when compiling postgresql
July 27th, 2011
It looks like the following compiling error has something to do pg_class.h
../../../../src/include/catalog/pg_class.h:32: error: expected \u2018)\u2019 before \u2018,\u2019 token
../../../../src/include/catalog/pg_class.h:78: warning: data definition has no type or storage class
../../../../src/include/catalog/pg_class.h:78: warning: type defaults to \u2018int\u2019 in declaration of \u2018FormData_pg_class\u2019
../../../../src/include/catalog/pg_class.h:89: error: expected \u2018=\u2019, \u2018,\u2019, \u2018;\u2019, \u2018asm\u2019 or \u2018__attribute__\u2019 before \u2018*\u2019 token
How to debug postgresql during initdb
July 25th, 2011
First, assume that you know how to debug postgresql on Linux (with gdb) during usual operations, such as the bugs appearing during a specific query processing.
Following is about how to troubleshoot problems that appear during initdb.
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Postgresql: how an index is physically created on disk
July 23rd, 2011
I am interested in where the files (holding the index) are being written, instead of the various indexing algorithms involved in building an index.
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A usable template database on Postgresql
July 21st, 2011
The contained database is named “test”. It contains only one table, whose schema is
create table tb(f1 int, f2 int);
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