Table of Contents

Property SelectCastClob

Namespace
YndigoBlue.Velocity.Data.Teradata
Assembly
YndigoBlue.Velocity.dll

SelectCastClob

Gets or sets whether CLOB columns are converted to VARCHAR before retrieval and export operations.

public bool SelectCastClob { get; set; }

Property Value

bool

Remarks

When enabled (default), CLOBs are automatically cast to VARCHAR when retrieving data via queries, full-text search, or export. This provides significant performance improvement because VARCHAR operations are much faster than CLOB operations in Teradata.

Trade-off:

  • Enabled (True - Default): Much faster retrieve, search, and export operations, but CLOB data is truncated to VarCharCastSize characters (default 32,000). Full-text search only indexes the first 32,000 characters. Most applications only need to display or search the beginning of large text, so this is usually acceptable.
  • Disabled (False): Slower retrieve and search operations, but full CLOB content (up to 2GB) is available. Use when you need to search or display complete CLOB content and query performance is secondary.

This setting applies to: Retrieve(), Search(), and Export() operations.

Recommendation: Keep enabled for performance unless your application specifically requires full-length CLOB retrieval.