Sp_iqrebuildindex error after upgrade to 15.4 ESD5

[Former Member]

Hello gurus,

I assume that lot of you has already done IQ migration from 15.2. I have got simple question.

One of our customers ugpraded his IQ server from 15.2 esd3 to 15.4 esd5.

After upgrade he also decided to rebuild all indexes including FP indexes.

He encoutered error message like this one with some FP indexes : Column ASIQ_IDX_T738_C8_FP has unsupported data type for index rebuild.

In this case column datatype is varbinary(16384). All other indexes like HG,LF ... was succesfully rebuilded.

How could he succeed in such FP index rebuild?

Regards,

Marian Stefancik

[markmumy · Accepted solution]

Certain versions of IQ did not allow you to run sp_iqrebuildindex on columns wider than 255 bytes.  I "think" that was addressed in IQ 16.

Prior to IQ 16, simply ignore rebuilding archer or varbinary larger than 255 bytes.

Mark

[Former Member · Accepted solution]

Hello Mark,

are there any other datatypes which should be ignored in rebuild routine?

Marian

[markmumy · Accepted solution]

No, not really.  Just the wider types that are not supported in IQ 15.  I would also look at the type of FP being rebuilt.  If the FP is already flat and the cardinality is high enough to warrant it always being flat, then why rebuild?  Clearly if an FP flipped to flat but now has a low enough cardinality to be placed in an optimized FP, you would want to rebuild to save space and processing time during loads and queries.

In reality, though, going from IQ 15.2 to IQ 15.4 should not warrant FP indexes being rebuilt other than the situation where we know we can save space.  Now when going to IQ 16, that's a different matter.  In IQ 16 we introduce a new flavor of default indexes (called n-bit).  The only way togged these new structures on existing data is a column rebuild.  And you will want to do it as it will save space and can dramatically help with queries.

Mark