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ftOraBlob

ftOraBlob = 30

Example​

function IsOracleBinaryLOB(Field: TField): Boolean;
begin
  Result := Field.DataType = ftOraBlob;
end;

Usage​

ftOraBlob identifies a legacy Oracle BLOB provider type that Velox exposes through generic binary blob streaming.

Additional Technical Info​

ftOraBlob is declaration ordinal 30 of TFieldType. It is the historic Delphi provider marker for an Oracle 8 binary large object. Modern providers may instead report a generic ftBlob, so code should normally test for the required capability rather than demand this legacy member.

The installed RTL maps ftOraBlob to TBlobField and treats it as base ftBlob during compatibility checks. Access therefore follows the dataset's blob-stream implementation. The marker supplies no file type, MIME type, compression, character encoding or object schema.

Use opaque byte or stream operations unless the column contract defines a payload. Whole-value conversions consume memory proportional to LOB size. Oracle locator lifetime, transaction visibility, prefetching, maximum size and concurrent-read behavior belong to the active database driver and session; this constant does not stabilise them.

When moving values across providers, preserve Null separately from a zero-length LOB and verify whether a live locator remains valid after scrolling, closing or committing. Do not retain the ordinal as an external database type code.

The example only inspects metadata and was source-reviewed; no Oracle connection, LOB, stream, dataset, database, runtime or image test ran.

External references

Created 2026-07-15