SAP Knowledge Base Article - Preview

2353544 - SAP IQ 16 query performance degradation when selecting a NULL AS column name in a VIEW


  • Queries using table VIEW's that JOIN multiple tables together via UNION ALL's
  • Missing column definitions for tables in the view are defined using NULL AS <column name>
  • Queries affected referencing the NULL AS defined column may see a performance degradation of up to 15x slower
  • Query plan comparisons between a query referencing a NULL AS column and one that does not shows the faster query uses a HASH PUSH DOWN JOIN and the slower uses JOIN HASH



  • SAP IQ 15.x and 16.x  systems on all platforms


SAP IQ 16.0


iq16, slow, deadlock, degradation, sybase table_view, tableview , 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 for Me (Login required).

Search for additional results

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