SAP Knowledge Base Article - Preview

2458615 - Converting a three byte FP index to a flat FP index using sp_iqrebuildindex()

Symptom

This is about how to convert a three byte FP index to a flat style FP index.
SAP IQ 15.x supports the new 3 byte FP Indexes in addition to the 1 and 2 byte taking tokenization to 16M values
This will improve both compression and performance.
But, there is a memory issue when handling three byte FP indexes created on wide columns, such as char(300).
If the column has 1.5 milion distinct values, then the lookup table for the three byte FP index will be at least 4.5 Gbytes in size.
It would be very big size to accomodate in memory when considering that it's just one FP index in one table.
So, it may cause overhead in managing the three byte FP index and cost too expensive than expected.


Read more...

Environment

SAP IQ 15.x

Product

SAP Sybase IQ 15.2

Keywords

SAP IQ, optimized FP index, tokenized FP index, rollover, roll over , KBA , BC-SYB-IQ , Sybase IQ , Problem

About this page

This is a preview of a SAP Knowledge Base Article. Click more to access the full version on SAP ONE Support launchpad (Login required).

Search for additional results

Visit SAP Support Portal's SAP Notes and KBA Search.