Frequently Asked Questions about Informix

$Id: ifaq.htm,v 1.21 2000/11/21 03:54:00 root Exp $

This document answers some of the questions which regularly appear in the Usenet Newsgroup comp.databases.informix. In addition to "frequent" questions I've also included questions which I consider useful or interesting.

Suggestions for improvement are most welcome.

Enjoy yourselves,

Current Maintainer


Previous Maintainers:


"Creator and Maintainer of the Informix FAQ, 1994-1997". Without Kerry this FAQ would not exist.

PS: Here is Kerry's awesome collection of awards:

Selected by PC Webopaedia


0 FAQ Facts

0.1 What's new in this release of the FAQ?


4.1.35 How can I compile the same 4gl program against multiple databases?
4.8.14 How do I use variable table/column names in SPL?
4.9 DBI::Informix (Perl)?
4.9.1 How do I unload to a file?
4.10.1 How can I connect without a password using JDBC?
4.10.2 How can I connect to SE using JDBC?
5.21 How do I run a stored procedure at certain times of the day?
5.23 Why do I get -1210 char to numeric errors in queries?
5.24 How good is statement caching under IDS 2000?
5.25 How do I keep my SQL portable?
6.57 How do I tune buffer waits?
6.58 Why should I not use RAID 5?
6.59 Are indexes bigger under 9.2?
6.60 Why is Online 9.14 so slow?
6.61 How do I configure DD_MASHMAX and DD_HASHSIZE?
6.62 How does Online page size vary across platforms?
6.63 What should I check when Online hangs?
6.64 Is IDS affected by Windows service packs?
6.65 When does onbar read the onconfig file?
6.66 Why are archives so slow and do they use the buffer cache?
6.67 How does NETTYPE work and how do I tune it?
8.52 Why do onspaces and other on-utilitys core dump?
8.53 How should I finish a restore (e.g. ontape -r)?
8.54 What are Codd's rules?
8.55 How do I link Informix tables to MS-Access?
8.56 How does OnBar compare to Ontape?
8.57 What are the main Informix bugs?
8.58 How do I debug onarchive failures?
8.59 How do I load blobs using dbaccess?
8.60 How do I identify outstanding in-place table alters?
8.61 How do I identify Server Versions from SQL?
8.62 How do I tell which session is using the most logical log space?
APPENDIX R Notes on Outer Joins


NOTE Nothing to add here

1.8 New Features by product (or: Why you should upgrade) Added info about the soon to be release 9.30.
8.13 What undocumented Online things are there? Add info from Art Kagel about LRUPOLICY to reduce LRU contention.
6.32 How do I reduce bufwaits? Added amended script from Daniel Willems to measure bufwaits
6.46 Does IDS support chunks more than 2Gb in size? Added info from Obnoxio The Clown that 8.3 has a larger platform dependent size, and that 9.3 could change things. Allegedly.
8.13 What undocumented Online things are there? Corrected PC_HASHSIZE and PC_POOLSIZE info. Also added info on DS_HASHSIZE and DS_POOLSIZE. All from Art Kagel. Also added from Tony Flaherty that setting SHMBASE to 0x0 on HPUX results in unreadable shared memory dumps as the internal pointers get screwed up in the dump file.

0.2 How can I get the latest copy of the FAQ?

0.2.1 anonymous ftp

The latest version of this document can be retrieved via anonymous ftp from the USA at ftp://ftp.iiug.org/pub/informix/faq/ifaq.tar.gz

If you've no knowledge of Unix, and have never heard of .gz or .tar formats, just get a copy of WinZip from http://www.winzip.com/ it's a very sexy Windows95/NT program which can decipher these for you.

0.2.2 World Wide Web

The primary site is London,England at http://www.smooth1.demon.co.uk/

Although the Informix-FAQ is available at many other sites on the Web, it is really only the two sites listed below who make an effort to keep their copies up-to-date.

If you are aware of somebody who *does* keep their version current please let me know and I'l be happy to include them in this list.


http://www.iiug.org/techinfo/faq/ifaq.htm (The International Informix User Group's site)

http://www.garpac.com/informix/ (Contact clay@garpac.com (Clay Irving))

0.2.3 comp.databases.informix

The FAQ is NEVER posted to c.d.i. because it's rather large, and posting hundreds of K into people's mailboxes isn't nice.

0.2.4 email

If you don't have access to FTP try using a FTP-by-mail server. Send a message with "help" in the subject line to the nearest one of:

0.3 Who do I complain to?

David Wiiliams
Home: djw@smooth1.demon.co.uk . Ph +44 0181 943 1889 (GMT)