Re: Quering the Sysmaster Database

In article <5gqol9$qjo@cssun.mathcs.emory.edu>, Clem Akins <clema@informix.com> writes >Hola, > >>Some time ago, I saw one or two Select statements on the syssqexplain table >>to verify aspects of cost and sorts, scans, indexes and temp files. I >>believe the queries are these : >> >>select [...] from syssqexplain [...] > >First, let's be sure that we all understand that this table (and many >others in the sysmaster db) are not documented, and their use is therefore >questionable. Queries like this one may be obviated at any time by >changing sysmaster schemas without any notice from Informix. I qoute: > "Many other tables in the sysmaster database are part of the > system-monitoring interface but are not documented. Their > schemas and column content might change from version to version." > -Informix-Universal Server > Administrator's Guide, Volume 2 > Version 9.01 > page 38-9, "The System-Monitoring Interface Tables" > (and it says the same thing for version 7.2, too) > Slobber...drool - wish I had Universal Server.... >>Every time I execute one of these queries (or any other query on the >>sysmaster database) my machine hangs and I have to reboot the server. > >*Any* other query? The manual also warns of dire (unpredictable) results >of certain actions involving the sysmaster database. Let us turn in our >hymnal to page 38-6, where it sayeth: > "Only user informix can query the SMI tables sysadtinfo and sysaudit." >(Though the worst you should get is a permission error.) > >>If anyone knows what this can be I'd like to know. I already contacted the >>Tech Support and they don't know why is this occuring. > >I do not know why this would occur, but if I were you I would do several >things before calling Informix support or writing c.d.i.: > >1) Ensure that the test query is run properly as user informix, against > documented, supported sysmaster tables. > >2) Use a very simple query that is immediately easy to understand. > >3) provide all the info you could about the nature of the "hang." (The > entire machine locks up and will not respond to anything but a > manual reboot? Or just the OnLine server?) > >Your goal here is to differentiate yourself from the vast majority of >users with a problem who have simply not RTFM. Do this by addressing the >potential causes of your problem as identified there. Then your purpose >is to provide your helpful audience with the information they need to >solve your problem--not too much data--(that will just get deleted) but >just the right amount. Try to present an interesting challenge to the >many nerds in the world with nothing better to do than searching for the >answers to someone else's problem on c.d.i. ;) Ooooh - that would be me...remember in Online releases < 7.13 you can get segmentation violations when quering the syssqexplain table... > >After all that, good luck. > > >______________________________________________________ >Clem Akins (aka clema@informix.com) >Informix Software, Inc (Standard disclaimers apply) >International Technical Support >Last seen: Strolling across moonlit Tiananmen Square -- David Williams