Indexes on Null values
User asked how Informix handles NULL values in indexed columns, contrasting with Oracle's behavior. Experts confirmed that Informix includes NULL values in all standard indexes, treating them as regular values. One respondent noted that GK indexes in XPS were an exception, though this feature was never completed for IDS.
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For oracle, I have read that nulls are not indexed. How does Informix handle null values on a column that has an index? Thanks
NULL values are included in all Informix indexes. Art Art S. Kagel Advanced DataTools (www.advancedatatools.com) Blog: http://informix-myview.blogspot.com/ Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on my employer, Advanced DataTools, the IIUG, nor any other organization with which I am associated either explicitly, implicitly, or by inference. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves. On Mon, Nov 19, 2012 at 12:53 PM, TAWNYA SUTHERLAND <trs@clerk.org> wrote: > For oracle, I have read that nulls are not indexed. How does Informix > handle > null values on a column that has an index? > > Thanks > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > --14dae9399c71178f8a04cedd1a6d
One of the rare ocasions where informix treats NULL as just another value. On Nov 19, 2012 6:54 PM, "TAWNYA SUTHERLAND" <trs@clerk.org> wrote: > For oracle, I have read that nulls are not indexed. How does Informix > handle > null values on a column that has an index? > > Thanks > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > --047d7b6d88b0d4514704cedeb855
Except in GK indexes in XPS. http://publib.boulder.ibm.com/infocenter/idshelp/v10/index.jsp?topic=/com.ibm.sq ls.doc/sqls199.htm Pity project Arrowhead was never completed and they are not available in IDS. I noice that mention of GK indexes is NOT in the version 11.7 Info Centre. When will this be added to IDS then? David. On 19 November 2012 at 18:15 Art Kagel <art.kagel@gmail.com> wrote: > NULL values are included in all Informix indexes. > > Art > > Art S. Kagel > Advanced DataTools (www.advancedatatools.com) > Blog: http://informix-myview.blogspot.com/ > > Disclaimer: Please keep in mind that my own opinions are my own opinions > and do not reflect on my employer, Advanced DataTools, the IIUG, nor any > other organization with which I am associated either explicitly, > implicitly, or by inference. Neither do those opinions reflect those of > other individuals affiliated with any entity with which I am affiliated nor > those of the entities themselves. > > On Mon, Nov 19, 2012 at 12:53 PM, TAWNYA SUTHERLAND <trs@clerk.org> wrote: > > > For oracle, I have read that nulls are not indexed. How does Informix > > handle > > null values on a column that has an index? > > > > Thanks > > > > > > > > > ******************************************************************************* > > Forum Note: Use "Reply" to post a response in the discussion forum. > > > > > > --14dae9399c71178f8a04cedd1a6d > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. >
Do you miss them?... Their usage is very specific... On Tue, Nov 20, 2012 at 12:06 AM, david@smooth1.co.uk <david@smooth1.co.uk>wrote: > Except in GK indexes in XPS. > > > > http://publib.boulder.ibm.com/infocenter/idshelp/v10/index.jsp?topic=/com.ibm.sq ls.doc/sqls199.htm > > Pity project Arrowhead was never completed and they are not available in > IDS. > > I noice that mention of GK indexes is NOT in the version 11.7 Info Centre. > > When will this be added to IDS then? > > David. > > On 19 November 2012 at 18:15 Art Kagel <art.kagel@gmail.com> wrote: > > NULL values are included in all Informix indexes. > > > > Art > > > > Art S. Kagel > > Advanced DataTools (www.advancedatatools.com) > > Blog: http://informix-myview.blogspot.com/ > > > > Disclaimer: Please keep in mind that my own opinions are my own opinions > > and do not reflect on my employer, Advanced DataTools, the IIUG, nor any > > other organization with which I am associated either explicitly, > > implicitly, or by inference. Neither do those opinions reflect those of > > other individuals affiliated with any entity with which I am affiliated > nor > > those of the entities themselves. > > > > On Mon, Nov 19, 2012 at 12:53 PM, TAWNYA SUTHERLAND <trs@clerk.org> > wrote: > > > > > For oracle, I have read that nulls are not indexed. How does Informix > > > handle > > > null values on a column that has an index? > > > > > > Thanks > > > > > > > > > > > > > > > > ******************************************************************************* > > > Forum Note: Use "Reply" to post a response in the discussion forum. > > > > > > > > > > --14dae9399c71178f8a04cedd1a6d > > > > > > > > ******************************************************************************* > > Forum Note: Use "Reply" to post a response in the discussion forum. > > > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > -- Fernando Nunes Portugal http://informix-technology.blogspot.com My email works... but I don't check it frequently... --047d7bb04b68dc70e904cee15ed4
Only because Ids does not have them. DB2 has statistical views, Oracle has cluster tables, IDS has...nothing... Wonder if this will make it into IDS 12? Regards, David. On 19 November 2012 at 23:21 Fernando Nunes <domusonline@gmail.com> wrote: > Do you miss them?... > Their usage is very specific... > > On Tue, Nov 20, 2012 at 12:06 AM, david@smooth1.co.uk > <david@smooth1.co.uk>wrote: > > > Except in GK indexes in XPS. > > > > > > > > > http://publib.boulder.ibm.com/infocenter/idshelp/v10/index.jsp?topic=/com.ibm.sq ls.doc/sqls199.htm > > > > Pity project Arrowhead was never completed and they are not available in > > IDS. > > > > I noice that mention of GK indexes is NOT in the version 11.7 Info Centre. > > > > When will this be added to IDS then? > > > > David. > > > > On 19 November 2012 at 18:15 Art Kagel <art.kagel@gmail.com> wrote: > > > NULL values are included in all Informix indexes. > > > > > > Art > > > > > > Art S. Kagel > > > Advanced DataTools (www.advancedatatools.com) > > > Blog: http://informix-myview.blogspot.com/ > > > > > > Disclaimer: Please keep in mind that my own opinions are my own opinions > > > and do not reflect on my employer, Advanced DataTools, the IIUG, nor any > > > other organization with which I am associated either explicitly, > > > implicitly, or by inference. Neither do those opinions reflect those of > > > other individuals affiliated with any entity with which I am affiliated > > nor > > > those of the entities themselves. > > > > > > On Mon, Nov 19, 2012 at 12:53 PM, TAWNYA SUTHERLAND <trs@clerk.org> > > wrote: > > > > > > > For oracle, I have read that nulls are not indexed. How does Informix > > > > handle > > > > null values on a column that has an index? > > > > > > > > Thanks > > > > > > > > > > > > > > > > > > > > > > > > ******************************************************************************* > > > > Forum Note: Use "Reply" to post a response in the discussion forum. > > > > > > > > > > > > > > --14dae9399c71178f8a04cedd1a6d > > > > > > > > > > > > > > ******************************************************************************* > > > Forum Note: Use "Reply" to post a response in the discussion forum. > > > > > > > > > > > > ******************************************************************************* > > Forum Note: Use "Reply" to post a response in the discussion forum. > > > > > > -- > Fernando Nunes > Portugal > > http://informix-technology.blogspot.com > My email works... but I don't check it frequently... > > --047d7bb04b68dc70e904cee15ed4 > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. >