Hi, I'm working on a database system and it's indexes, but I'm having a really hard time seing the clear difference between a covering index and a clustered index. I've googled my way around but hasn't got a clear cut answer on: What is the differences between the two types of indexes When do I use Covering index and when do I use Cl...
ASP.net app inserts Microsoft Windows 2007 .docx file into a row on DB2 OS/390 Blob table. A different VB.net app gets the DB2 OS/390 Blob data. VB.net app kicks off Microsoft Word to open the .docx file but then Microsoft Word pops up a message that the data is corrupted. Word will allow you to fix the data so the file can be viewed ...
I would like to learn working with IMS, can somebody suggest me a good source? I'm not sure if it matters to say that I have quite good exposure and experience with INSYNC DB2 and QMF. So anything that can depict and explain the advantages and disadvantages over IMS would be really helpful. Please provide me a good page where i get good ...
I have a simple (actually simplified :) ) scenario that is possibly the cause for the headache I've been having for the last few days... My current application (that serves 100's of users) currently uses Oracle as the database. I have no stored procs (I wish actually). Now, I've been asked if the product will work if I migrate to IBM ...
Hi, I’m having a question about the fine line between the gain of an index to a table there is growing steadily in size every month and the gain of queries with an index. The situation is, that I’ve two tables, Table1 and Table2. Each table grows slowly but regularly each month (with about 100 new rows for Table1 and a couple of rows f...
I have a table Course and every Course has many Resources. Course ========== course_id Resource ========== course_id number I want something like a separate autoincrement for each course_id. Or, in other words, I want to auto-enumerate the resources for a given course. For example, the resource table could look something like: cours...
Hi, I have a question regarding a semi-constant update in a database. In short it is regarding a checkout function on a web page, which each time the checkout function is evoked it do five steps. I want to try to optimize this function and have my eye on a step where I update a table each time the checkout is performed. I take the info...
Hi, I have this Python script: import sys import getopt import timeit import random import os import re import ibm_db import time from string import maketrans runs=5 queries=50 file = open("results.txt", "a") for r in range(5): print "Run %s\n" % r os.system("python reads.py -r1 -pquery1.sql -q50 -sespec") file.write('END...
Hi, I’m working on optimizing some of my queries and I have a query that states: select * from SC where c_id ="+c_id” The schema of ** SC** looks like this: SC ( c_id int not null, date_start date not null, date_stop date not null, r_t_id int not null, nt int, t_p decimal, PRIMARY KEY (c_id, r_t_id, date_start, date_stop)); My ...
I need to execute the command . /home/db2v95/sqllib/db2profile before I can import ibm_db_dbi in Python 2.6. Executing it before I enter Python works: baldurb@gigur:~$ . /home/db2v95/sqllib/db2profile baldurb@gigur:~$ python Python 2.6.4 (r264:75706, Dec 7 2009, 18:45:15) [GCC 4.4.1] on linux2 Type "help", "copyright", "credits" or "...
Hi, I'm trying to create a database connection in a python script to my DB2 database. When the connection is done I've to run some different SQL statements. I googled the problem and has read the ibm_db API (http://code.google.com/p/ibm-db/wiki/APIs) but just can't seem to get it right. Here is what I got so far: import sys import ge...
We had a talk with colleagues about databases yesterday as we will have a DB2 education in few weeks. I'm wondering, what are the differences between DB2 and Oracle as two major enterprise solutions? Are there any limitations in comparison to each other? Are there any tasks more suitable for DB2 or Oracle? (I found this article, but I s...
Hi, I’m working on tuning and increasing the performance of my IBM DB2 version 9.7 database. I’ve been searching around the net for the last couple of days and learned that if I created my tables in COMPRESS mode and created one more bufferpool and set both of them to access 1024mb, then the performance in my queries should increase bec...
Hi, I've a python script which works just as it should but I need to write the time for the execution. I've gooled that I should use timeit but I can't seem to get it to work. My Python script looks like this: import sys import getopt import timeit import random import os import re import ibm_db import time from string import maketran...
how to find all indexes available on table in db2 ...
Hi, I am running some queries in my database and want to increase the performance and have created some indexes but I still think that the response time is to great so I want to see if I can create a better or another index to increase the speed. My schema for the table I think has the biggest bottleneck look like this: R_D( **id** i...
I have been trying to read a file in "cp037" encoding scheme using JAVA. I able to read a file in basic encoding schemes like UTF-8, UTF16 etc...After a bit of research on the internet i came to know that we need charset.jar or international version of JRE be installed to support extended encoding schemes. Can anyone send me a link for i...
Is there any difference between these two queries? select * from tbl where ts < '9999-12-31-24.00.00.000000'; and select * from tbl where ts < timestamp('9999-12-31-24.00.00.000000'); When is the timestamp function required? Is there a difference in performance? ...
Can I use DML in from clause in DB2? thank you ...
I can do any .Net development using v2 of the CLR (.net 2, 3, 3.5) but when I try to use .Net 4.0 then I get an error saying that the version of IBM.Data.DB2 is too old / out of date (it's compiled for CLR v2). Where would I find a .Net 4 version of IBM.Data.DB2? ...