Frequently Asked Questions about Informix

$Id: informix.htm,v 1.24 2005/05/15 01:15:00 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

David Williams (david@smooth1.co.uk)

Previous Maintainers:

Kerry Sainsbury (kerry@kcbbs.gen.nz)

"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:

Contents

• 0 FAQ Facts:
• 0.1 What's new in this release of the FAQ?
• 0.2 How can I get the latest copy of the FAQ?
• 0.2.1 anonymous ftp
• 0.2.2 World Wide Web
• 0.2.3 comp.databases.informix
• 0.2.4 email
• 0.3 Who do I complain to?
• 1 Frivolous background stuff:
• 1.1 Who, or what, is Informix?
• 1.2 The Informix Time-line
• 1.3 How do you pronounce "Informix"?
• 1.4 What products do Informix sell, and what do they do?
• 1.4.1 Engines
• 1.4.2 Tools
• 1.4.3 Connectivity Packages
• 1.5 What're the differences between Turbo/Online/SE/4GL/RDS/ESQL...
• 1.5.1 Online vs Standard Engine.
• 1.5.2 Online vs Turbo.
• 1.5.3 4GL vs 4GL-RDS.
• 1.5.4 4GL vs 4GL for Windows vs 4GL/GX
• 1.5.5 ESQL/C vs 4GL
• 1.5.6 HyperScript Tools vs WingZ
• 1.5.6.1 What is Datalink?
• 1.6 What are TPC-C benchmarks?
• 1.7 What are the meaning of the acronyms used in this newsgroup?
• 1.8 New Features by product (or: Why you should upgrade)
• 1.9 How does Informix QA their products?
• 1.10 How do Informix version numbers work??
• 2 Not so frivolous background stuff:
• 2.1 Who are we - comp.databases.informix
• 2.1.1 How do I join the list or unsubscribe?
• 2.1.2 How can I search the newsgroup?
• 2.1.3 How should I post a problem to the group?
• 2.3 What's the Consensus on Job Postings?
• 2.4 Other User Groups
• 2.5 Other Mailing lists
• 3 Tell me More about...
• 3.1 The Integrated Debugger
• 3.1.1 How useful is the Interactive Debugger?
• 3.2 4GL for Windows
• 3.2.1 Does 4GX run p-code or does it compile to an object?
• 3.2.2 What is performance like, compared to "normal" 4GL?
• 3.2.3 What's the main benefit of using 4GL/GX
• 3.2.4 What problems might I encounter?
• 3.3 I-Star/I-Net
• 3.3.1 What are they?
• 3.3.2 When do I need one and when the other?
• 4 Common Questions about tools:
• 4.1 Informix-4GL
• 4.1.1 I keep getting -4518 errors! How can I fix this problem?
• 4.1.2 How can I write to a flat ASCII file?
• 4.1.3 How can I read from a flat ASCII file?
• 4.1.4 How can I force INPUT ARRAY onto the next line?
• 4.1.5 How can I make a screen dump?
• 4.1.6 Any undocumented features that I could play with?
• 4.1.6.1 fgl_drawbox(depth, width, y, x, color)
• 4.1.6.2 FREE <statement-id|cursor-name>
• 4.1.6.3 Undocumented math functions from SELECT
• 4.1.6.4 Is there a "get_key" function, or similar
• 4.1.7 Performance tips (Code Optimization)
  • 4.1.7.1 INITIALIZE vs LET
  • 4.1.7.2 String Constants
  • 4.1.7.3 Displaying of forms
  • 4.1.7.4 Function call vs RETURNING
  • 4.1.7.5 ORDER EXTERNAL BY
• 4.1.8 Performance tips (Design Optimization)
  • 4.1.8.1 Modularize Executables
  • 4.1.8.2 RUN WITHOUT WAITING
  • 4.1.8.3 UPDATE WHERE CURRENT OF
  • 4.1.8.4 INSERT CURSOR
  • 4.1.8.5 OPEN vs OPEN, CLOSE
  • 4.1.8.6 Move Math from Query to Application
  • 4.1.8.7 Avoid Scroll Cursors
  • 4.1.8.8 Update Necessary Columns Only
  • 4.1.8.9 Organize Common Operations into Functions
  • 4.1.8.10 Reduce Transaction Length
  • 4.1.8.11 SELECT needed columns only
• 4.1.9 How can I use #DEFINE-style constructs, like C?
• 4.1.10 Why are RUN's return codes screwy?
• 4.1.11 Are there any RDS compatibility problems?
• 4.1.12 Can you link Compiled I4GL functions into a custom P-code runner?
• 4.1.13 How can I check if any rows exist, without OPEN-FETCH-CLOSE?
• 4.1.14 How do you include Printer control characters in an Informix Report?
• 4.1.15 How can I dynamically change Report OPTIONs at runtime?
• 4.1.16 My .err files are incomplete
• 4.1.17 Can I run a Stored Procedure from 4GL?
• 4.1.18 What problems will I have upgrading from 4.x to 6/7.x?
• 4.1.19 Tips on running 4GL via Cron
• 4.1.20 Will Informix explode in the year 2000?
• 4.1.21 How can I use GNU C (gcc) with 4GL?
• 4.1.22 Why does 4GL generate invalid dates when it performs arithmetic with months?
• 4.1.23 How do I disconnect from the engine in 4GL?
• 4.1.24 How does free work?
• 4.1.25 Removed
• 4.1.26 How do I find the Nth root of Number in 4GL?
• 4.1.27 What was the first version 6.01 release of 4GL?
• 4.1.28 How do I get the P-Code version of a .4go?
• 4.1.29 How do I stop error logging after calling startlog()?
• 4.1.30 How do I use shared libraries under HP-UX?
• 4.1.31 How should I handle locking in 4GL programs?
• 4.1.32 How can I use Purify with 4GL programs?
• 4.1.33 How can I properly log errors with 4GL programs?
• 4.1.34 What should the function main in a 4gl program contain?
• 4.1.35 How can I compile the same 4gl program against multiple databases?
• 4.2 ESQL/C:
• 4.2.1 Why have Informix duplicated stleng, stcopy() etc in ESQL/C?
• 4.2.2 How can I get a list of databases?
• 4.2.3 Can I use ESQL with C++?
• 4.2.4 How are prepared statement id's defined in ESQL/C?
• 4.2.5 How do I use ESQL/C in a makefile?
• 4.2.6 How does the fetch buffer work?
• 4.2.7 Why do set-uid programs not work?
• 4.2.8 How can I generate unique cursor names?
• 4.3 ACE:
• 4.3.1 How do I call a custom C function from ACE?
• 4.3.2 How can I create unique output filenames?
• 4.3.3 How can I set isolation levels in an ACE report?
• 4.3.4 How can I set isolation levels in Perform?
• 4.4 WingZ 1.0:
• 4.4.1 How can I make DataLink not pop-up 'no rows found'-style dialog boxes
• 4.5 Hyperscript Tools:
• 4.5.1 How do I run a Hyperscript Worksheet directly from a Windows Icon?
• 4.5.2 Which is better Datalens or built-in SQL?
• 4.6 Informix-4GL for Windows
• 4.6.1 How can I get a UK Pound sign as my MONEY code?
• 4.7 Informix-NewEra
• 4.7.1 What 4GL to NewEra conversion tools exist?
• 4.7.2 Arrgh: -4518 in NewEra too!
• 4.7.3 How generate 4GL from .WIF without Window Painter?
• 4.7.4 What's the performance difference between base types and object types?
• 4.7.5 Can't run New Era 2.0 applications under Win 95
• 4.7.6 How can I find New Era -1363 errors?
• 4.7.7 What New Era Class Libraries are there?
• 4.8 Stored Procedure Language (SPL)?
• 4.8.1 What is SPL?
• 4.8.2 Advantages of SPL
• 4.8.3 Disadvantages of SPL
• 4.8.4 Can I access the SQLCA via a Stored Procedure?
• 4.8.5 When should I use a SP rather than 4GL?
• 4.8.6 How do I convert Sybase Stored Procedures to Informix?
• 4.8.7 When are Stored Procedures optimized?
• 4.8.8 How do I generate random numbers in SPL?
• 4.8.9 How do return Julian dates in SPL?
• 4.8.10 Can I create Stored Procedures in ISQL?
• 4.8.11 How do I find the current database in SPL?
• 4.8.12 How do write a substr function in SPL?
• 4.8.13 Why does CURRENT always return the same value in SPL?
• 4.8.14 How do I use variable table/column names in SPL?
• 4.8.15 Can I declare cursors in SPL?
• 4.9 DBI::Informix (Perl)?
• 4.9.1 How do I unload to a file?
• 4.9.2 How do I write a simple program in DBI?
• 4.10 Java?
• 4.10.1 How can I connect without a password using JDBC?
• 4.10.2 How can I connect to SE using JDBC?
• 5 Common SQL Questions:
• 5.1 How can I speed up my SQL commands?
• 5.1.1 SELECTs using sorts or joins
• 5.1.2 SELECTs using NOT IN or NOT EXISTS clauses
• 5.1.3 Use of SET EXPLAIN ON
• 5.1.4 Avoid "OR"
• 5.1.5 Use Indexes
• 5.2 How can I use the results of an SQL query in a shell script?
• 5.3 Why can't I create a view with a calc column
• 5.4 How can I access data outside the current database?
• 5.4.1 Using Standard Engine
• 5.4.1.1 The Legal Method
• 5.4.1.2 The Dodgey Method
• 5.4.2 Using Online
• 5.5 How can I SELECT rows in detail-table missing a matching header-table row
• 5.6 How can I SELECT a fraction (say 10%) of the database
• 5.7 I want to CREATE a TEMP TABLE LIKE permanent table
• 5.8 How to convince the optimizer to use indexes YOU want
• 5.9 How to alter the next SERIAL number
• 5.10 How can I speed up SELECT COUNT(DISTINCT)?
• 5.11 Is there *really* no "Upper" function!?
• 5.12 How can I remove duplicate keys from a table?
• 5.13 Should I use Constraints?
• 5.14 Removed
• 5.15 How can I stop an SQL script if an error occurs?
• 5.16 Why do I get locks on sysprocplan?
• 5.17 How do I set the number of decimal places used in ISQL?
• 5.18 How do I calculate standard deviations in SQL?
• 5.19 How do I convert intervals?
• 5.20 How do I do case insensitive searches?
• 5.21 How do I run a stored procedure at certain times of the day?
• 5.22 Is UNLOAD (and so also LOAD) a real SQL statement?
• 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 Common Questions about the Engine:
• 6.1 What're some pointers for configuring Online?
• 6.2 What do I need to use MS-Access/Visual Basic with my Informix database?
• 6.3 What do I do if online fails to start?
• 6.4 What error messages are caused by locking problems?
• 6.5 What should I use instead of kill -9?
• 6.6 How can I tell what version I'm running?
  • 6.6.1 Look in the ASCII files:
  • 6.6.2 Ask the programs by passing the -V switch:
  • 6.6.3 Ask the engine itself:
• 6.7 Locking in pre-6.0 engines
• 6.7.1 What is the "Twin Problem"?
• 6.7.2 How does this work and what are the ramifications?
• 6.7.3 What OS bugs may affect online?
• 6.8 Space reclamation
• 6.9 Online Disk Fragmentation
• 6.10 Why do UPDATE STATISTICS?
• 6.11 How do we get serial field starting values for a table
• 6.12 Can I count the number of rows SELECTed, without using SELECT COUNT?
• 6.13 Is the number of rows processed in the SQLERRD structure accurate?
• 6.14 Interpreting SysColumns.ColType and SysColumns.ColLength
• 6.15 More tuning suggestions for Online
• 6.16 DATETIME, INTERVAL and other tricks
• 6.17 Reading SE Audit Trails
• 6.18 Recovering broken (or missing) indexes in SE
• 6.19 What about Replication?
• 6.20 How well does Online scale?
• 6.21 How do I tune KAIO?
• 6.22 Why does ontape not notice when I change device names in onconfig?
• 6.23 How do I reduce checkpoint times?
• 6.24 Why does Online show up as "oninit -r" processes?
• 6.25 What are these CDRD_ threads?
• 6.26 What does onstat -h do?
• 6.27 How do I start up Extended Parallel Server?
• 6.28 How many AIO VPs should I have?
• 6.29 How should I use mirroring + striping?
• 6.30 Why is shared memory not freed when my session ends?
• 6.31 Do deattached indexes take up more space?
• 6.32 How do I reduce bufwaits?
• 6.33 What status codes does onstat return?
• 6.34 Why does ontape dislike norewind devices?
• 6.35 Any known issues with shared memory connections?
• 6.36 Any fast backup methods under IDS 7.3?
• 6.37 Is IDS 7.3 most robust when crashes occur?
• 6.38 Is raw disk faster than cooked files?
• 6.39 Should online run as root or informix?
• 6.40 Should online chunks be owned by root or informix?
• 6.41 Can archives hang the system waiting for a tape?
• 6.42 Is it worth binding Online VPs myself?
• 6.43 Subqueries are not working under IDS 7.3 - help?
• 6.44 What is a .FCx release of Online?
• 6.45 How many semaphores does online need?
• 6.46 Does IDS support chunks more than 2Gb in size?
• 6.47 Why am I getting lots of busy waits?
• 6.48 Why do checkpoints sometimes hang?
• 6.49 What is this mt.c mentioned in online crashes?
• 6.50 Why does onstat sometimes fail with a changing data structure error?
• 6.51 What are the restrictions with Workgroup Server?
• 6.52 How can I tell how well Online buffering is working per table?
• 6.53 What can I do if Online ends up hung?
• 6.54 How do I fix permission on Informix binaries?
• 6.55 How do I detect network errors with Online?
• 6.56 What if I get a mt_notifyvp time out error with Online?
• 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_HASHMAX 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?
• 6.68 Compatibility between NT 4.0 service packs and IDS?
• 6.69 How do I calculate the network bandwidth required for ER?
• 6.70 Why do I get out of disk space during a warm restore?
• 6.71 What is the difference between latches, mutexes and locks?
• 6.72 What does the output of onstat -C (pre IDS 10.0) mean?
• 6.73 What does the output at the end of onstat -u mean?
• 6.74 Why are all sessions hung on the nsf.lock mutex?
• 6.75 Why does the first CPU VP work harder than the others?
• 6.76 How do I fix permissions on files under $INFORMIXDIR?
• 6.77 What is a light scan?
• 6.78 What happens during an archive?
• 6.79 How do I disable fuzzy checkpoints?
• 6.80 How do I see free space in a sbspace?
• 6.81 Do logical log switches affect Enterprise Replication?
• 6.82 What is the sh_lock spin lock?
• 6.83 What does "mt yield n" mean in the wait statistics?
• 6.84 How do I add more than 10 shared memory segments under AIX?
• 6.85 What are the fields of the ixbar file?
• 6.86 Should I use striping?
• 7 Connectivity Questions
• 7.1 I-Net/Star Security
• 7.2 I-Net is slow... Help!
• 7.3 Intermittant problems with I-NET vs SCO
• 7.4 I-NETgives -932 errors and complains about getservbyname (WSANO_DATA)
• 7.5 Intersolves ODBC Driver complain it is unable to load locale categories.
• 7.6 How do I set lock mode from a client server app?
• 8 DBA Issues
• 8.1 Performance - make it go faster!
• 8.2 Should I use Online DSA mirroring?
• 8.3 Questions about NFS mounted databases
• 8.4 How can I run ontape/tbtape from a cron job?
• 8.5 Calculating extent sizes
• 8.6 How can I list a table's dbspace?
• 8.7 How should I use the "informix" user & group?
• 8.8 How can I measure CPU time?
• 8.9 Using ISQL/DBACCESS to optimize SELECTs
• 8.10 dbexported & imported - now runs like a dog!
• 8.11 How do I find which dbspace a database resides in?
• 8.12 How do I find out if the network is causing performance problems?
• 8.13 What undocumented Online things are there?
• 8.14 How do I enable KAIO?
• 8.15 How do I do a warm restore of a dbspace using OnBar?
• 8.16 Which queries are not parallelized?
• 8.17 How do I check my backups?
• 8.18 How do I find out how much of my logical logs are in use?
• 8.19 Do I need a storage manager to run OnBar?
• 8.20 How do I track which sessions are doing the most I/O?
• 8.21 How do I setup the High Performance Loader (HPL)?
• 8.22 How do access NT databases from UNIX?
• 8.23 How do use SMI tables to locate logical logs?
• 8.24 How do use SMI tables to find table space usage?
• 8.25 Why does oncheck warn me about more than 8 extents?
• 8.26 Why does the High Performance Loader give no errors?
• 8.27 Why does fragment elimination using dates fail?
• 8.28 When dbimporting why do I get string to date errors?
• 8.29 How can I speed up sorts and index builds?
• 8.30 How can I handle duplicates when loading data?
• 8.31 How do I dbexport when CDR is enabled?
• 8.32 Why can the DBA not grant permissions on this view?
• 8.33 Can I run ontape to a disk file?
• 8.34 How can I list all tables in a dbspace?
• 8.35 Is there anything faster than dbexport?
• 8.36 How do I setup OnBar and Legato?
• 8.37 How do I get information about tables from sysmaster?
• 8.38 How do I use Oncockpit?
• 8.39 Where do sqexplain.out's appear under NT?
• 8.40 How do I use locales under Informix?
• 8.41 How do I use optimize index builds?
• 8.42 How do I calculate how much space an index will use?
• 8.43 Why do I get error -197?
• 8.44 How do I log the queries informix receives?
• 8.45 Any hints for running more than one onbar process at a time?
• 8.46 How can I use Legato with onbar?
• 8.47 How can I update statistics in parallel?
• 8.48 How do I locate temporary tables?
• 8.49 How do I set tables memory resident?
• 8.50 How do I find column dependencies for a Stored Procedure?
• 8.51 How do I performance tune Onbar?
• 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?
• 8.63 Is the High Performance Loader (HPL) really that quick?
• 8.64 Can I connect to the database server without connecting to a database?
• 8.65 How do I run HPL job without the GUI?
• 8.66 Are there any tools that can display table relationships visually?
• 8.67 Are there any tools that check SQL for portability?
• 8.68 What is the ISO standard date format?
• 8.69 What does the "mode" column indicate in the sysprocedures table?
• 8.70 How can I drop a database in a down dbspace?
• 8.71 How can I find the number of index and data pages for a table from sysmaster?
• 8.72 How can I debug dbschema when it fails?
• 8.73 How can I debug onbar when it fails?
• 8.74 When should I use varchars?
• 8.75 How does Enterprise Replication do timestamp conflict resolution?
• 8.76 How can I calculate the remaining extents for a table?
• 8.77 Is it ok to use buffered logging for databases?
• 8.78 Should I fragment my indicies?
• 8.79 Can I see what temporary tables are in use?
• 8.80 How can I calculate suggested extent sizes for a table?
• 8.81 How can I calculate the memory needed for a hash join?
• 8.82 How do I setup Enterprise Replication (ER)?
• 8.83 How do I handle a long transaction?
• 9 Configuring things
• 9.1 Environment variables
• 9.1.1 DBESCWT
• 9.1.2 DBSCREENOUT and DBSCREENDUMP
• 9.2 How do you read termcap's ZA string?
• 9.3 Where can I get a termcap for ...?
• 9.4 How do I define function keys 37 thru 64?
• 9.5 How can I run Informix Online under Solaris 2.4?
• 10 Gimme something for nothing, what's available?
• 10.1 Informix Archive Sites
• 10.2 Is there a Perl interface to Informix?
• 10.2.1 A simple interface
• 10.2.2 isqlperl
• 10.2.3 DBD::Informix
• 10.2.4 Vortex Perl
• 10.2.5 DBD::Illustra
• 10.3 What about Mac Client Software?
• 10.4 Is there an RDS de-compiler available?
• 10.5 What about a GUI interface?
• 10.6 Recommended free software
• 10.7 Is there any Web Server software available?
• 10.8 Are there any Technical Interview Questions available?
• 10.9 Is there a Python interface to Informix?
• 10.10 Is there an OLE DB interface to Informix?
• 10.11 Are there any notes on sysmaster?
• 10.12 Are there any notes on onstat?
• 11 Miscellany
• 11.1 What machines get ported to first?
• 11.2 I've finished the FAQ, what else can I read?
• 11.3 Is there any Informix info on The Web?
• 11.4 List of major bugs fixed in the various versions
• 11.5 What is Informix-Link?
• 11.6 Does Informix run under Linux?
• 11.7 Tell me more about product X, Y, or Z
• 11.8 Are the Informix Manuals available electronically?
• 11.9 How do I get my own Informix engineer on-site?
• 12 Third Party Products
• 12.1 Hyperscript Tools
• 12.2 4GL Clones
• 12.2.1 Querix
• 12.2.2 F4GL Compiler
• 12.2.3 Etrus Software Corporation
• 12.2.4 A 4GL for Linux clone
• 12.3 Fourgen-CASE
• 12.4 ODBC Drivers
• 12.5 JDBC Drivers
• 12.6 Talking to a Mac
• 12.7 Crystal Reports Class Library
• 12.8 Any pointers on configuring Peoplesoft?
• 12.9 What about Metacube OLAP?
• 12.10 Infoflex ESQL and SE clone
• 12.11 Peerdirect Data Replication
• 12.12 Peoplesoft Mailing List
• 12.13 SPL Debugger for Informix
• 12.14 OLE DB
• 13. Datablades
• 13.1 How do I write a simple datablade?
• Appendices
• APPENDIX A Temporary String Space (TSS)
• APPENDIX B Sample 4GL Routine to read ASCII files
• APPENDIX C Sample C Routine to read ASCII files
• APPENDIX D C Routine to give a list of databases
• APPENDIX E How to interpret syscolumns (in English)
• APPENDIX F How to interpret syscolumns (in 4GL)
• APPENDIX G GUI builders summary
• APPENDIX H Shell to list Informix versions
• APPENDIX I DATETIME, INTERVAL and other tricks
• APPENDIX J Dynamically changing Report OPTIONs
• APPENDIX K Calculating extent sizes
• APPENDIX L dbschema with extents
• APPENDIX M How to put Blobs into Reports
• APPENDIX N How do I compile ESQL/C code for use with C++?
• APPENDIX O A Review of Informix vs. Oracle
• APPENDIX P Logical Log Tape Validator for Online 5.x
• APPENDIX Q OnBar setup with Legato
• APPENDIX R Notes on Outer Joins
• APPENDIX S Chars and Varchars
• Credits

0 FAQ Facts

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

• Cosmo gets his own section (a new one - the first proper new section I've done) in the FAQ - 13. Datablades...All hail Cosmo!
• Obnoxio, Paul Watson,Rajib Sarkar,Andrew Hamm,Stefan Weideneder Colin Bull and Jacob Salomon all get their first entries
• First update in an even longer time
• New Primary location for the FAQ (www.smooth1.co.uk) and new email address for the maintainer (david@smooth1.co.uk)
• Updated to include version IDS version 10!

NEW!

1.10 How do Informix version numbers work??

4.8.15 Can I declare cursors in SPL?

4.9.2 How do I write a simple program in DBI?

6.3 What do I do if online fails to start?

6.68 Compatibility between NT 4.0 service packs and IDS?

6.69 How do I calculate the network bandwidth required for ER?

6.70 Why do I get out of disk space during a warm restore?

6.71 What is the difference between latches, mutexes and locks?

6.72 What does the output of onstat -C (pre IDS 10.0) mean?

6.73 What does the output at the end of onstat -u mean?

6.74 Why are all sessions hung on the nsf.lock mutex?

6.75 Why does the first CPU VP work harder than the others?

6.76 How do I fix permissions on files under $INFORMIXDIR?

6.77 What is a light scan?

6.78 What happens during an archive?

6.79 How do I disable fuzzy checkpoints?

6.80 How do I see free space in a sbspace?

6.81 Do logical log switches affect Enterprise Replication?

6.82 What is the sh_lock spin lock?

6.83 What does "mt yield n" mean in the wait statistics?

6.84 How do I add more than 10 shared memory segments under AIX?

6.85 What are the fields of the ixbar file?

6.86 Should I use striping?

8.63 Is the High Performance Loader (HPL) really that quick?

8.64 Can I connect to the database server without connecting to a database?

8.65 How do I run HPL job without the GUI?

8.66 Are there any tools that can display table relationships visually?

8.67 Are there any tools that check SQL for portability?

8.68 What is the ISO standard date format?

8.69 What does the "mode" column indicate in the sysprocedures table?

8.70 How can I drop a database in a down dbspace?

8.71 How can I find the number of index and data pages for a table from sysmaster?

8.72 How can I debug dbschema when it fails?

8.73 How can I debug onbar when it fails?

8.74 When should I use varchars?

8.75 How does Enterprise Replication do timestamp conflict resolution?

8.76 How can I calculate the remaining extents for a table?

8.77 Is it ok to use buffered logging for databases?

8.78 Should I fragment my indicies?

8.79 Can I see what temporary tables are in use?

8.80 How can I calculate suggested extent sizes for a table?

8.81 How can I calculate the memory needed for a hash join?

8.82 How do I setup Enterprise Replication (ER)?

8.83 How do I handle a long transaction?

10.12 Are there any notes on onstat?

13.1 How do I write a simple datablade?

IMPROVED!

1.8 New Features by product (or: Why you should upgrade) Added info from Jonathan Leffler on XPS 8.3. Added info from Raj Muralidharan on max chunk size for XPS 8.3

1.9 How does Informix QA their products? Added info from Madison Pruet on the testing suite Informix use. Added info from Madison Pruet on how porting and betas are done.

1.10 How do Informix version numbers work?? Added info from Andrew Hamm about what does and does not get included in an interim release.

4.8.13 Why does CURRENT always return the same value in SPL? Added info from Leonid Belov on how to get the current datetime from sysmaster.

5.9 How to alter the next SERIAL number Added info from Jonathan Leffler on C-ISAM.

6.32 How do I reduce bufwaits? Added info from Art Kagel that gives more detail.

6.33 What status codes does onstat return? Replaced with info from Mark D. Stock that includes XPS onstat return codes.

6.36 Any fast backup methods under IDS 7.3? Added info from Andrew Hamm (his first mention in the FAQ!) suggesting increasing TAPEBLK and LTAPEBLK.

6.38 Is raw disk faster than cooked files? Added more tests by Toni Arte that show raw disk is faster. Added more tests by Colin Bull that show raw disk is faster.

6.58 Why should I not use RAID 5? Added info from Paul Watson (Another new person in the FAQ!) confirming the disk failures run in batches.

6.61 How do I configure DD_HASHMAX and DD_HASHSIZE? Added info from Michael Mueller.

6.62 How does Online page size vary across platforms? Added info from Obnoxio The Clown that sequent is also a 4K page size. Obnoxio finally gets a credit in the FAQ! Added info from Art Kagel on XPS, that the old Turbo engine on Amdahl mainframes was 4K and that although 5.xx has a PAGESIZE onconfig parameter it should not be changed!

8.13 What undocumented Online things are there? Mentioned NOLRUPRIO. Added info from Stefan Weideneder on WSTATS are how to read the output. (Stefan gets his first entry in the FAQ!) Added info from Glyn Balmer on smartdisk. Added info from Madison Pruet. (Clarence?)

10.11 Are there any notes on sysmaster? Updated URL and Paul Watson's email address.

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.co.uk

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.

USA:

http://www.iiug.org/techinfo/faq/informix.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:

ftpmail@decwrl.dec.com

ftpmail@sunsite.unc.edu

ftpmail@doc.ic.ac.uk

ftp-mailer@informatik.tu-muenchen.de

ftpmail@grasp.insa-lyon.fr

ftpmail@cs.uow.edu.au

0.3 Who do I complain to?

David Wiiliams

Home: david@smooth1.co.uk . Ph +44 0208 662 0864 (GMT)