Informix Experts




For a complete list of current SQL reserved words, see the IBM Informix Guide to SQL: Syntax.


Sanjit Chakraborty[Read More]

OAT Version 2.23 Available Now!

cheetahblog Tags:  openadmin oat 4,091 Views

The newest version of OpenAdmin Tool for IDS, Version 2.23, has just been released! Download the new version today to get the enhanced SQL Explorer and version 2.0 of the ER Plugin.



New feature highlights:



The SQL Explorer has been newly redesigned. New features include

  • Filters and search fields for viewing SQL tracing data.
  • Support for different SQL trace levels - global or user - so you can manage what kinds of SQL information are traced for IDS V11.50.xC1 servers.
  • Support for suspending and resuming history tracing, without releasing resources, on IDS V11.50.xC1 servers.


ER Plug-in Version 2.0: Version 2.0 of OAT’s ER plug-in includes a new Replicate Explorer and becomes the first step in supporting ER administration graphically through OAT.





  • The Replicate Explorer now lets you monitor your replicates and replicate sets.
  • Screenshot of the Replicate Explorer



  • The Node Details -> Configuration page now supports the editing and updating of ER configuration parameters






Download OAT Version 2.23 now at https://www14.software.ibm.com/webapp/iwm/web/preLogin.do?lang=en_US&source=swg-informixfpd



For additional information on OpenAdmin Tool for IDS, including feature details, screenshots and demos, go to www.openadmintool.org.

Erika Von Bargen

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C-Style Comment Indicator with DB-Access

cheetahblog Tags:  dbaccess comment 4,088 Views


Earlier versions of Informix Dynamic Server (IDS) had restriction with C-style comment indicators ( /* ... */ ) in SQL statements, within the DB–Access operations.



Without the C-style comment indicator it was not compliance with SQL-99 standard and caused problems while migrate from other databases server.



Starting with IDS Version 11.10, restrictions with C-style comment are no longer in effect. Any of the following styles SQL comment indicators can be use in all DB–Access statements.



  • Double hyphen ( -- ) complies with the ANSI/ISO standard for SQL
  • Braces ( { } ) are an Informix extension to the ANSI/ISO standard
  • C-style slash-and-asterisk ( /* . . . */ ) comply with the SQL-99 standard



The comment symbol indicator can be choosing depends on ANSI/ISO compliance requirements.



Comment symbol indicator can be use on the same line with the SQL statement. It can spans across single-line or multiple-line, but cannot be nested.



DB-Access will filter any comments before sending SQL statement to the database server.



Examples:  -- Double hyphen comment  SELECT * FROM orders;     -- Selects all columns and rows                            -- from the orders table

{ Comment using braces } SELECT * FROM orders; { Selects all columns and rows from the orders table }

/* C-style comment */ SELECT * FROM orders; /* Selects all columns and rows from the orders table */


Sanjit Chakraborty
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How to monitor your SQL Shared Memory Caches

cheetahblog Tags:  performance cache 4,083 Views


I don’t know about the rest of you, but I have had a lot ofproblems truly determining if my SQL Cache settings are efficient. If my UserDefined Routine (UDR) cache, for example, always seems to be 50% full, does that mean thecache only uses 50% and so the settings are to high, or are they at 50% becauseI’m constantly cleaning the pools, and thus I’m configured too low. Beginning in Cheetah you now have a means to diagnose thattype of information, and it’s located in the sysmaster database. The table name is syssqlcacheprof, and it contains profileinformation for each of the caches.



 



Below is a sample output from this table:



 





 



 



As you can see in the above you can now quickly identify how often the cache is removing entries (orcleaning), and what the efficiency is of your cache, in terms of a hit rate. Infact a very simple query that could be used for analyzing the hit ratio for the caches would be:



 



select *, (hits/(hits+misses)) hit_ratio from syssqlcacheprof



 



This table also provides youthe benefit of quickly seeing how much memory each cache is actually using,something that before Cheetah was a bit awkward to calculate. While not a major feature of Cheetah, this new sysmaster table is a valuable new asset in performance tuning.




Mark Jamison[Read More]