[firebird-support] Blob is null performance question

[Maya Opperman]

Hi,

Is it possible to indicate in a SQL statement whether a blob contains data or 
not, without retrieving the entire blob, and thereby making the query very slow?

Eg. If I did:

select
  S.StockCode,
  (case S.StockImageBlob when null then 'No' else 'Yes') as HasImage,
 (case S.StockMemoBlob when null then 'No' else 'Yes') as HasMemo
>From StockTable S

Would that still need to read the entire blob and cause speed degradation?

Thanks
Maya



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